From b7a03f7dc3b6eb47957d0840d76178f2f42933eb Mon Sep 17 00:00:00 2001 From: Stefan Feilmeier Date: Sat, 8 Jan 2022 00:24:21 +0100 Subject: [PATCH] Backend-Code clean-up and modernization for Java 11 (#1692) - Clean-up code using Eclipse IDE - Apply checkstyle - Use Java 11 features - mainly the `var` keyword, where appropriate --- cnf/checkstyle.xml | 2 +- .../backend/application/BackendApp.java | 25 ++- .../io/openems/backend/b2brest/B2bRest.java | 6 +- .../openems/backend/b2brest/RestHandler.java | 24 +-- .../backend/b2bwebsocket/B2bWebsocket.java | 8 +- .../openems/backend/b2bwebsocket/OnClose.java | 5 +- .../openems/backend/b2bwebsocket/OnOpen.java | 10 +- .../backend/b2bwebsocket/OnRequest.java | 6 +- .../SubscribedEdgesChannelsWorker.java | 19 +- .../backend/b2bwebsocket/WebsocketServer.java | 2 +- .../openems/backend/b2bwebsocket/WsData.java | 15 +- .../EdgesCurrentDataNotification.java | 15 +- .../SubscribeEdgesChannelsRequest.java | 57 +++-- .../b2bwebsocket/B2bWebsocketTest.java | 43 ++-- .../backend/b2bwebsocket/TestClient.java | 22 +- .../AbstractOpenemsBackendComponent.java | 12 +- .../common/edgewebsocket/EdgeWebsocket.java | 6 +- .../common/jsonrpc/JsonRpcRequestHandler.java | 2 +- .../jsonrpc/request/AddEdgeToUserRequest.java | 12 +- .../GetEdgesChannelsValuesRequest.java | 30 +-- .../request/GetEdgesStatusRequest.java | 8 +- .../request/GetSetupProtocolRequest.java | 8 +- .../request/GetUserInformationRequest.java | 6 +- .../jsonrpc/request/RegisterUserRequest.java | 8 +- .../request/SetUserInformationRequest.java | 10 +- .../request/SubmitSetupProtocolRequest.java | 12 +- .../response/AddEdgeToUserResponse.java | 4 +- .../GetEdgesChannelsValuesResponse.java | 8 +- .../response/GetEdgesStatusResponse.java | 4 +- .../response/GetUserInformationResponse.java | 8 +- .../common/metadata/AbstractMetadata.java | 2 +- .../openems/backend/common/metadata/Edge.java | 82 +++++-- .../backend/common/metadata/Metadata.java | 74 ++++--- .../openems/backend/common/metadata/User.java | 37 ++-- .../backend/common/timedata/EdgeCache.java | 22 +- .../backend/common/timedata/Timedata.java | 8 +- .../common/uiwebsocket/UiWebsocket.java | 6 +- .../EdgeRpcRequestHandler.java | 32 ++- .../JsonRpcRequestHandlerImpl.java | 40 ++-- .../edgewebsocket/EdgeWebsocketImpl.java | 74 ++++--- .../backend/edgewebsocket/OnClose.java | 9 +- .../backend/edgewebsocket/OnError.java | 10 +- .../backend/edgewebsocket/OnNotification.java | 29 ++- .../openems/backend/edgewebsocket/OnOpen.java | 13 +- .../backend/edgewebsocket/OnRequest.java | 2 +- .../edgewebsocket/SystemLogHandler.java | 27 ++- .../edgewebsocket/WebsocketServer.java | 30 +-- .../openems/backend/edgewebsocket/WsData.java | 40 ++-- .../backend/metadata/dummy/DummyMetadata.java | 34 ++- .../backend/metadata/file/FileMetadata.java | 20 +- .../backend/metadata/odoo/EdgeCache.java | 53 +++-- .../openems/backend/metadata/odoo/Field.java | 39 ++-- .../openems/backend/metadata/odoo/MyUser.java | 2 +- .../backend/metadata/odoo/OdooMetadata.java | 46 ++-- .../metadata/odoo/odoo/Credentials.java | 2 +- .../metadata/odoo/odoo/FieldValue.java | 2 +- .../metadata/odoo/odoo/OdooHandler.java | 185 ++++++++-------- .../metadata/odoo/odoo/OdooUserRole.java | 8 +- .../backend/metadata/odoo/odoo/OdooUtils.java | 203 +++++++++--------- .../metadata/odoo/postgres/Credentials.java | 2 +- .../odoo/postgres/InitializeEdgesWorker.java | 6 +- .../odoo/postgres/PeriodicWriteWorker.java | 29 ++- .../metadata/odoo/postgres/PgUtils.java | 17 +- .../odoo/postgres/PostgresHandler.java | 8 +- .../odoo/postgres/QueueWriteWorker.java | 30 +-- .../odoo/postgres/task/DatabaseTask.java | 4 +- .../postgres/task/InsertEdgeConfigUpdate.java | 4 +- .../task/InsertOrUpdateDeviceStates.java | 6 +- .../odoo/postgres/task/UpdateEdgeConfig.java | 4 +- .../postgres/task/UpdateEdgeProducttype.java | 4 +- .../postgres/task/UpdateEdgeStateActive.java | 4 +- .../odoo/postgres/task/UpdateSumState.java | 4 +- .../backend/timedata/dummy/TimedataDummy.java | 8 +- .../timedata/influx/ChannelFormula.java | 8 +- .../influx/FieldTypeConflictHandler.java | 54 +++-- .../backend/timedata/influx/Influx.java | 112 +++++----- .../backend/uiwebsocket/impl/OnClose.java | 7 +- .../backend/uiwebsocket/impl/OnRequest.java | 64 +++--- .../impl/SubscribedChannelsWorker.java | 6 +- .../uiwebsocket/impl/UiWebsocketImpl.java | 44 ++-- .../uiwebsocket/impl/WebsocketServer.java | 4 +- .../backend/uiwebsocket/impl/WsData.java | 25 ++- 82 files changed, 1027 insertions(+), 955 deletions(-) diff --git a/cnf/checkstyle.xml b/cnf/checkstyle.xml index cc887fb5119..ba4b0fbf0ee 100644 --- a/cnf/checkstyle.xml +++ b/cnf/checkstyle.xml @@ -108,7 +108,7 @@ - + diff --git a/io.openems.backend.application/src/io/openems/backend/application/BackendApp.java b/io.openems.backend.application/src/io/openems/backend/application/BackendApp.java index 66b58e5c16d..03b6c1165c8 100644 --- a/io.openems.backend.application/src/io/openems/backend/application/BackendApp.java +++ b/io.openems.backend.application/src/io/openems/backend/application/BackendApp.java @@ -1,7 +1,6 @@ package io.openems.backend.application; import java.io.IOException; -import java.util.Dictionary; import java.util.Hashtable; import org.osgi.service.cm.Configuration; @@ -23,22 +22,22 @@ public class BackendApp { private final Logger log = LoggerFactory.getLogger(BackendApp.class); @Reference - ConfigurationAdmin cm; + private ConfigurationAdmin cm; @Activate - void activate() { - String message = "OpenEMS Backend version [" + OpenemsConstants.VERSION + "] started"; - String line = Strings.repeat("=", message.length()); - log.info(line); - log.info(message); - log.info(line); + private void activate() { + final var message = "OpenEMS Backend version [" + OpenemsConstants.VERSION + "] started"; + final var line = Strings.repeat("=", message.length()); + this.log.info(line); + this.log.info(message); + this.log.info(line); Configuration config; try { - config = cm.getConfiguration("org.ops4j.pax.logging", null); - Dictionary properties = config.getProperties(); + config = this.cm.getConfiguration("org.ops4j.pax.logging", null); + final var properties = config.getProperties(); if (properties == null || properties.isEmpty() || properties.get("log4j2.rootLogger.level") == null) { - Hashtable log4j = new Hashtable<>(); + final var log4j = new Hashtable(); log4j.put("log4j2.appender.console.type", "Console"); log4j.put("log4j2.appender.console.name", "console"); log4j.put("log4j2.appender.console.layout.type", "PatternLayout"); @@ -58,8 +57,8 @@ void activate() { } @Deactivate - void deactivate() { - log.info("Deactivate BackendApp"); + private void deactivate() { + this.log.info("Deactivate BackendApp"); } } diff --git a/io.openems.backend.b2brest/src/io/openems/backend/b2brest/B2bRest.java b/io.openems.backend.b2brest/src/io/openems/backend/b2brest/B2bRest.java index fd165f6c747..a7d7f97ec5c 100644 --- a/io.openems.backend.b2brest/src/io/openems/backend/b2brest/B2bRest.java +++ b/io.openems.backend.b2brest/src/io/openems/backend/b2brest/B2bRest.java @@ -42,18 +42,18 @@ public B2bRest() { } @Activate - void activate(Config config) throws OpenemsException { + private void activate(Config config) throws OpenemsException { this.startServer(config.port()); } @Deactivate - void deactivate() { + private void deactivate() { this.stopServer(); } /** * Create and start new server. - * + * * @param port the port * @throws OpenemsException on error */ diff --git a/io.openems.backend.b2brest/src/io/openems/backend/b2brest/RestHandler.java b/io.openems.backend.b2brest/src/io/openems/backend/b2brest/RestHandler.java index f038015f9c7..ef6cc491eeb 100644 --- a/io.openems.backend.b2brest/src/io/openems/backend/b2brest/RestHandler.java +++ b/io.openems.backend.b2brest/src/io/openems/backend/b2brest/RestHandler.java @@ -72,7 +72,7 @@ public void handle(String target, Request baseRequest, HttpServletRequest reques /** * Authenticate a user. - * + * * @param request the HttpServletRequest * @return the {@link User} * @throws OpenemsNamedException on error @@ -80,7 +80,7 @@ public void handle(String target, Request baseRequest, HttpServletRequest reques private User authenticate(HttpServletRequest request) throws OpenemsNamedException { String authHeader = request.getHeader("Authorization"); if (authHeader != null) { - StringTokenizer st = new StringTokenizer(authHeader); + var st = new StringTokenizer(authHeader); if (st.hasMoreTokens()) { String basic = st.nextToken(); if (basic.equalsIgnoreCase("Basic")) { @@ -92,8 +92,8 @@ private User authenticate(HttpServletRequest request) throws OpenemsNamedExcepti } int p = credentials.indexOf(":"); if (p != -1) { - String username = credentials.substring(0, p).trim(); - String password = credentials.substring(p + 1).trim(); + var username = credentials.substring(0, p).trim(); + var password = credentials.substring(p + 1).trim(); // authenticate using username & password return this.parent.metadata.authenticate(username, password); } @@ -140,7 +140,7 @@ private void sendErrorResponse(Request baseRequest, HttpServletResponse response /** * Parses a Request to JSON. - * + * * @param baseRequest the Request * @return the {@link JsonObject} * @throws OpenemsException on error @@ -159,7 +159,7 @@ private static JsonObject parseJson(Request baseRequest) throws OpenemsException /** * Handles an http request to 'jsonrpc' endpoint. - * + * * @param user the {@link User} * @param baseRequest the {@link Request} * @param httpRequest the {@link HttpServletRequest} @@ -167,7 +167,7 @@ private static JsonObject parseJson(Request baseRequest) throws OpenemsException */ private void handleJsonRpc(User user, Request baseRequest, HttpServletRequest httpRequest, HttpServletResponse httpResponse) { - UUID requestId = new UUID(0L, 0L); /* dummy UUID */ + var requestId = new UUID(0L, 0L); /* dummy UUID */ try { // call handler methods if (!httpRequest.getMethod().equals("POST")) { @@ -176,7 +176,7 @@ private void handleJsonRpc(User user, Request baseRequest, HttpServletRequest ht } // parse json and add "jsonrpc" and "id" properties if missing - JsonObject json = RestHandler.parseJson(baseRequest); + var json = RestHandler.parseJson(baseRequest); if (!json.has("jsonrpc")) { json.addProperty("jsonrpc", "2.0"); } @@ -184,9 +184,9 @@ private void handleJsonRpc(User user, Request baseRequest, HttpServletRequest ht json.addProperty("id", UUID.randomUUID().toString()); } if (json.has("params")) { - JsonObject params = JsonUtils.getAsJsonObject(json, "params"); + var params = JsonUtils.getAsJsonObject(json, "params"); if (params.has("payload")) { - JsonObject payload = JsonUtils.getAsJsonObject(params, "payload"); + var payload = JsonUtils.getAsJsonObject(params, "payload"); if (!payload.has("jsonrpc")) { payload.addProperty("jsonrpc", "2.0"); } @@ -198,11 +198,11 @@ private void handleJsonRpc(User user, Request baseRequest, HttpServletRequest ht json.add("params", params); } // parse JSON-RPC Request - JsonrpcMessage message = JsonrpcMessage.from(json); + var message = JsonrpcMessage.from(json); if (!(message instanceof JsonrpcRequest)) { throw new OpenemsException("Only JSON-RPC Request is supported here."); } - JsonrpcRequest request = (JsonrpcRequest) message; + var request = (JsonrpcRequest) message; // handle the request CompletableFuture responseFuture = this.parent.jsonRpcRequestHandler diff --git a/io.openems.backend.b2bwebsocket/src/io/openems/backend/b2bwebsocket/B2bWebsocket.java b/io.openems.backend.b2bwebsocket/src/io/openems/backend/b2bwebsocket/B2bWebsocket.java index 1adc16df348..98e4587567e 100644 --- a/io.openems.backend.b2bwebsocket/src/io/openems/backend/b2bwebsocket/B2bWebsocket.java +++ b/io.openems.backend.b2bwebsocket/src/io/openems/backend/b2bwebsocket/B2bWebsocket.java @@ -52,17 +52,17 @@ public B2bWebsocket() { private Config config; private final Runnable startServerWhenMetadataIsInitialized = () -> { - this.startServer(config.port(), config.poolSize(), config.debugMode()); + this.startServer(this.config.port(), this.config.poolSize(), this.config.debugMode()); }; @Activate - void activate(Config config) { + private void activate(Config config) { this.config = config; this.metadata.addOnIsInitializedListener(this.startServerWhenMetadataIsInitialized); } @Deactivate - void deactivate() { + private void deactivate() { ThreadPoolUtils.shutdownAndAwaitTermination(this.executor, 5); this.metadata.removeOnIsInitializedListener(this.startServerWhenMetadataIsInitialized); this.stopServer(); @@ -70,7 +70,7 @@ void deactivate() { /** * Create and start new server. - * + * * @param port the port * @param poolSize number of threads dedicated to handle the tasks * @param debugMode activate a regular debug log about the state of the tasks diff --git a/io.openems.backend.b2bwebsocket/src/io/openems/backend/b2bwebsocket/OnClose.java b/io.openems.backend.b2bwebsocket/src/io/openems/backend/b2bwebsocket/OnClose.java index 10789be885d..cd6d1427d80 100644 --- a/io.openems.backend.b2bwebsocket/src/io/openems/backend/b2bwebsocket/OnClose.java +++ b/io.openems.backend.b2bwebsocket/src/io/openems/backend/b2bwebsocket/OnClose.java @@ -1,12 +1,9 @@ package io.openems.backend.b2bwebsocket; -import java.util.Optional; - import org.java_websocket.WebSocket; import org.slf4j.Logger; import org.slf4j.LoggerFactory; -import io.openems.backend.common.metadata.User; import io.openems.common.exceptions.OpenemsException; public class OnClose implements io.openems.common.websocket.OnClose { @@ -21,7 +18,7 @@ public OnClose(B2bWebsocket parent) { @Override public void run(WebSocket ws, int code, String reason, boolean remote) throws OpenemsException { WsData wsData = ws.getAttachment(); - Optional user = wsData.getUserOpt(); + var user = wsData.getUserOpt(); if (user.isPresent()) { this.parent.logInfo(this.log, "User [" + user.get().getName() + "] closed connection"); } else { diff --git a/io.openems.backend.b2bwebsocket/src/io/openems/backend/b2bwebsocket/OnOpen.java b/io.openems.backend.b2bwebsocket/src/io/openems/backend/b2bwebsocket/OnOpen.java index 310d2c971fe..917ef5eecd9 100644 --- a/io.openems.backend.b2bwebsocket/src/io/openems/backend/b2bwebsocket/OnOpen.java +++ b/io.openems.backend.b2bwebsocket/src/io/openems/backend/b2bwebsocket/OnOpen.java @@ -28,21 +28,21 @@ public void run(WebSocket ws, JsonObject handshake) throws OpenemsNamedException try { // Read "Authorization" header for Simple HTTP authentication. Source: // https://stackoverflow.com/questions/16000517/how-to-get-password-from-http-basic-authentication - final String authorization = JsonUtils.getAsString(handshake, "Authorization"); + final var authorization = JsonUtils.getAsString(handshake, "Authorization"); if (authorization == null || !authorization.toLowerCase().startsWith("basic")) { throw OpenemsError.COMMON_AUTHENTICATION_FAILED.exception(); } String base64Credentials = authorization.substring("Basic".length()).trim(); byte[] credDecoded = Base64.getDecoder().decode(base64Credentials); - String credentials = new String(credDecoded, StandardCharsets.UTF_8); + var credentials = new String(credDecoded, StandardCharsets.UTF_8); // credentials = username:password - final String[] values = credentials.split(":", 2); + final var values = credentials.split(":", 2); if (values.length != 2) { throw OpenemsError.COMMON_AUTHENTICATION_FAILED.exception(); } - String username = values[0]; - String password = values[1]; + var username = values[0]; + var password = values[1]; User user = this.parent.metadata.authenticate(username, password); WsData wsData = ws.getAttachment(); diff --git a/io.openems.backend.b2bwebsocket/src/io/openems/backend/b2bwebsocket/OnRequest.java b/io.openems.backend.b2bwebsocket/src/io/openems/backend/b2bwebsocket/OnRequest.java index b85f866ad23..591341b0ff9 100644 --- a/io.openems.backend.b2bwebsocket/src/io/openems/backend/b2bwebsocket/OnRequest.java +++ b/io.openems.backend.b2bwebsocket/src/io/openems/backend/b2bwebsocket/OnRequest.java @@ -27,7 +27,7 @@ public OnRequest(B2bWebsocket parent) { public CompletableFuture run(WebSocket ws, JsonrpcRequest request) throws OpenemsException, OpenemsNamedException { WsData wsData = ws.getAttachment(); - User user = wsData.getUserWithTimeout(5, TimeUnit.SECONDS); + var user = wsData.getUserWithTimeout(5, TimeUnit.SECONDS); switch (request.getMethod()) { @@ -42,7 +42,7 @@ public CompletableFuture run(WebSocket ws, Jso /** * Handles a {@link SubscribeEdgesChannelsRequest}. - * + * * @param wsData the WebSocket attachment * @param user the {@link User} * @param messageId the JSON-RPC Message-ID @@ -58,7 +58,7 @@ private CompletableFuture handleSubscribeEdgesCha } // activate SubscribedChannelsWorker - SubscribedEdgesChannelsWorker worker = wsData.getSubscribedChannelsWorker(); + var worker = wsData.getSubscribedChannelsWorker(); worker.handleSubscribeEdgesChannelsRequest(request); // JSON-RPC response diff --git a/io.openems.backend.b2bwebsocket/src/io/openems/backend/b2bwebsocket/SubscribedEdgesChannelsWorker.java b/io.openems.backend.b2bwebsocket/src/io/openems/backend/b2bwebsocket/SubscribedEdgesChannelsWorker.java index 1d4f7d4b9e4..f3a8f42c4e9 100644 --- a/io.openems.backend.b2bwebsocket/src/io/openems/backend/b2bwebsocket/SubscribedEdgesChannelsWorker.java +++ b/io.openems.backend.b2bwebsocket/src/io/openems/backend/b2bwebsocket/SubscribedEdgesChannelsWorker.java @@ -6,7 +6,6 @@ import java.util.concurrent.ScheduledFuture; import java.util.concurrent.TimeUnit; -import org.java_websocket.WebSocket; import org.slf4j.Logger; import org.slf4j.LoggerFactory; @@ -15,7 +14,6 @@ import io.openems.backend.b2bwebsocket.jsonrpc.notification.EdgesCurrentDataNotification; import io.openems.backend.b2bwebsocket.jsonrpc.request.SubscribeEdgesChannelsRequest; -import io.openems.backend.common.metadata.User; import io.openems.common.exceptions.OpenemsError.OpenemsNamedException; import io.openems.common.session.Role; import io.openems.common.types.ChannelAddress; @@ -54,7 +52,7 @@ public SubscribedEdgesChannelsWorker(B2bWebsocket parent, WsData wsData) { /** * Applies a SubscribeChannelsRequest. - * + * * @param request the SubscribeEdgesChannelsRequest */ public synchronized void handleSubscribeEdgesChannelsRequest(SubscribeEdgesChannelsRequest request) { @@ -66,7 +64,7 @@ public synchronized void handleSubscribeEdgesChannelsRequest(SubscribeEdgesChann /** * Updates the Subscription data. - * + * * @param edgeIds Set of Edge-IDs * @param channels Set of ChannelAddresses */ @@ -91,7 +89,7 @@ private synchronized void updateSubscription(Set edgeIds, Set edgeIds, Set user = new CompletableFuture(); + private final CompletableFuture user = new CompletableFuture<>(); public WsData(B2bWebsocket parent) { this.parent = parent; @@ -35,6 +35,14 @@ public CompletableFuture getUser() { return this.user; } + /** + * Gets the logged in User with a timeout. + * + * @param timeout the timeout length + * @param unit the {@link TimeUnit} of the timeout + * @return the {@link User} + * @throws OpenemsNamedException on error + */ public User getUserWithTimeout(long timeout, TimeUnit unit) throws OpenemsNamedException { try { return this.user.get(timeout, unit); @@ -49,7 +57,7 @@ public Optional getUserOpt() { /** * Gets the SubscribedChannelsWorker to take care of subscribe to CurrentData. - * + * * @return the SubscribedChannelsWorker */ public SubscribedEdgesChannelsWorker getSubscribedChannelsWorker() { @@ -60,9 +68,8 @@ public SubscribedEdgesChannelsWorker getSubscribedChannelsWorker() { public String toString() { if (this.user == null) { return "B2bWebsocket.WsData [user=UNKNOWN]"; - } else { - return "B2bWebsocket.WsData [user=" + user + "]"; } + return "B2bWebsocket.WsData [user=" + this.user + "]"; } @Override diff --git a/io.openems.backend.b2bwebsocket/src/io/openems/backend/b2bwebsocket/jsonrpc/notification/EdgesCurrentDataNotification.java b/io.openems.backend.b2bwebsocket/src/io/openems/backend/b2bwebsocket/jsonrpc/notification/EdgesCurrentDataNotification.java index 7d6143e13bf..36a50f361d7 100644 --- a/io.openems.backend.b2bwebsocket/src/io/openems/backend/b2bwebsocket/jsonrpc/notification/EdgesCurrentDataNotification.java +++ b/io.openems.backend.b2bwebsocket/src/io/openems/backend/b2bwebsocket/jsonrpc/notification/EdgesCurrentDataNotification.java @@ -14,7 +14,7 @@ /** * Represents a JSON-RPC Notification for sending the current data of all * subscribed Channels of multiple Edges. - * + * * 
  * {
  *   "jsonrpc": "2.0",
@@ -34,20 +34,27 @@ public class EdgesCurrentDataNotification extends JsonrpcNotification {
 	private final Table values = HashBasedTable.create();
 
 	public EdgesCurrentDataNotification() {
-		super(METHOD);
+		super(EdgesCurrentDataNotification.METHOD);
 	}
 
+	/**
+	 * Adds a value to the notification.
+	 * 
+	 * @param edgeId  the Edge-ID
+	 * @param channel the {@link ChannelAddress}
+	 * @param value   the value
+	 */
 	public void addValue(String edgeId, ChannelAddress channel, JsonElement value) {
 		this.values.put(edgeId, channel, value);
 	}
 
 	@Override
 	public JsonObject getParams() {
-		JsonObject j = new JsonObject();
+		var j = new JsonObject();
 		for (Entry> row : this.values.rowMap().entrySet()) {
 			String edgeId = row.getKey();
 			Map columns = row.getValue();
-			JsonObject jEdge = new JsonObject();
+			var jEdge = new JsonObject();
 			for (Entry column : columns.entrySet()) {
 				ChannelAddress channel = column.getKey();
 				JsonElement value = column.getValue();
diff --git a/io.openems.backend.b2bwebsocket/src/io/openems/backend/b2bwebsocket/jsonrpc/request/SubscribeEdgesChannelsRequest.java b/io.openems.backend.b2bwebsocket/src/io/openems/backend/b2bwebsocket/jsonrpc/request/SubscribeEdgesChannelsRequest.java
index 38ccd729fff..733100b96b9 100644
--- a/io.openems.backend.b2bwebsocket/src/io/openems/backend/b2bwebsocket/jsonrpc/request/SubscribeEdgesChannelsRequest.java
+++ b/io.openems.backend.b2bwebsocket/src/io/openems/backend/b2bwebsocket/jsonrpc/request/SubscribeEdgesChannelsRequest.java
@@ -14,7 +14,7 @@
 
 /**
  * Represents a JSON-RPC Request to subscribe to Channels of multiple Edges.
- * 
+ *
  * 
  * {
  *   "jsonrpc": "2.0",
@@ -32,24 +32,38 @@ public class SubscribeEdgesChannelsRequest extends JsonrpcRequest {
 
 	public static final String METHOD = "subscribeEdgesChannels";
 
+	/**
+	 * Builds a {@link SubscribeEdgesChannelsRequest} from a {@link JsonrpcRequest}.
+	 * 
+	 * @param r the {@link JsonrpcRequest}
+	 * @return the {@link SubscribeEdgesChannelsRequest}
+	 * @throws OpenemsNamedException on error
+	 */
 	public static SubscribeEdgesChannelsRequest from(JsonrpcRequest r) throws OpenemsNamedException {
-		JsonObject p = r.getParams();
-		int count = JsonUtils.getAsInt(p, "count");
-		SubscribeEdgesChannelsRequest result = new SubscribeEdgesChannelsRequest(r, count);
-		JsonArray edgeIds = JsonUtils.getAsJsonArray(p, "ids");
+		var p = r.getParams();
+		var count = JsonUtils.getAsInt(p, "count");
+		var result = new SubscribeEdgesChannelsRequest(r, count);
+		var edgeIds = JsonUtils.getAsJsonArray(p, "ids");
 		for (JsonElement edgeId : edgeIds) {
 			result.addEdgeId(JsonUtils.getAsString(edgeId));
 		}
-		JsonArray channels = JsonUtils.getAsJsonArray(p, "channels");
+		var channels = JsonUtils.getAsJsonArray(p, "channels");
 		for (JsonElement channel : channels) {
-			ChannelAddress address = ChannelAddress.fromString(JsonUtils.getAsString(channel));
+			var address = ChannelAddress.fromString(JsonUtils.getAsString(channel));
 			result.addChannel(address);
 		}
 		return result;
 	}
 
+	/**
+	 * Builds a {@link SubscribeEdgesChannelsRequest} from a {@link JsonObject}.
+	 * 
+	 * @param j the {@link JsonObject}
+	 * @return the {@link SubscribeEdgesChannelsRequest}
+	 * @throws OpenemsNamedException on error
+	 */
 	public static SubscribeEdgesChannelsRequest from(JsonObject j) throws OpenemsNamedException {
-		return from(GenericJsonrpcRequest.from(j));
+		return SubscribeEdgesChannelsRequest.from(GenericJsonrpcRequest.from(j));
 	}
 
 	private final int count;
@@ -57,27 +71,42 @@ public static SubscribeEdgesChannelsRequest from(JsonObject j) throws OpenemsNam
 	private final TreeSet channels = new TreeSet<>();
 
 	private SubscribeEdgesChannelsRequest(JsonrpcRequest request, int count) {
-		super(request, METHOD);
+		super(request, SubscribeEdgesChannelsRequest.METHOD);
 		this.count = count;
 	}
 
 	public SubscribeEdgesChannelsRequest(int count) {
-		super(METHOD);
+		super(SubscribeEdgesChannelsRequest.METHOD);
 		this.count = count;
 	}
 
+	/**
+	 * Adds an Edge-ID.
+	 * 
+	 * @param edgeId the Edge-ID.
+	 */
 	public void addEdgeId(String edgeId) {
 		this.edgeIds.add(edgeId);
 	}
 
+	/**
+	 * Removes an Edge-ID.
+	 * 
+	 * @param edgeId the Edge-ID
+	 */
 	public void removeEdgeId(String edgeId) {
 		this.edgeIds.remove(edgeId);
 	}
 
 	public TreeSet getEdgeIds() {
-		return edgeIds;
+		return this.edgeIds;
 	}
 
+	/**
+	 * Adds a Channel.
+	 * 
+	 * @param address the {@link ChannelAddress}
+	 */
 	public void addChannel(ChannelAddress address) {
 		this.channels.add(address);
 	}
@@ -87,16 +116,16 @@ public int getCount() {
 	}
 
 	public TreeSet getChannels() {
-		return channels;
+		return this.channels;
 	}
 
 	@Override
 	public JsonObject getParams() {
-		JsonArray edgeIds = new JsonArray();
+		var edgeIds = new JsonArray();
 		for (String edgeId : this.edgeIds) {
 			edgeIds.add(edgeId);
 		}
-		JsonArray channels = new JsonArray();
+		var channels = new JsonArray();
 		for (ChannelAddress address : this.channels) {
 			channels.add(address.toString());
 		}
diff --git a/io.openems.backend.b2bwebsocket/test/io/openems/backend/b2bwebsocket/B2bWebsocketTest.java b/io.openems.backend.b2bwebsocket/test/io/openems/backend/b2bwebsocket/B2bWebsocketTest.java
index 4ad0fc7a177..fa63b164e9f 100644
--- a/io.openems.backend.b2bwebsocket/test/io/openems/backend/b2bwebsocket/B2bWebsocketTest.java
+++ b/io.openems.backend.b2bwebsocket/test/io/openems/backend/b2bwebsocket/B2bWebsocketTest.java
@@ -6,14 +6,12 @@
 import java.util.Base64;
 import java.util.HashMap;
 import java.util.Map;
-import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
 
 import io.openems.backend.b2bwebsocket.jsonrpc.request.SubscribeEdgesChannelsRequest;
 import io.openems.backend.common.jsonrpc.request.GetEdgesChannelsValuesRequest;
 import io.openems.backend.common.jsonrpc.request.GetEdgesStatusRequest;
 import io.openems.common.exceptions.OpenemsError.OpenemsNamedException;
-import io.openems.common.jsonrpc.base.JsonrpcResponseSuccess;
 import io.openems.common.jsonrpc.request.SetGridConnScheduleRequest;
 import io.openems.common.jsonrpc.request.SetGridConnScheduleRequest.GridConnSchedule;
 import io.openems.common.types.ChannelAddress;
@@ -32,22 +30,23 @@ public class B2bWebsocketTest {
 
 	private static TestClient prepareTestClient() throws URISyntaxException, InterruptedException {
 		Map httpHeaders = new HashMap<>();
-		String auth = new String(Base64.getEncoder().encode((USERNAME + ":" + PASSWORD).getBytes()),
+		var auth = new String(
+				Base64.getEncoder().encode((B2bWebsocketTest.USERNAME + ":" + B2bWebsocketTest.PASSWORD).getBytes()),
 				StandardCharsets.UTF_8);
 		httpHeaders.put("Authorization", "Basic " + auth);
-		TestClient client = new TestClient(new URI(URI), httpHeaders);
+		var client = new TestClient(new URI(B2bWebsocketTest.URI), httpHeaders);
 		client.startBlocking();
 		return client;
 	}
 
 	// @Test
-	public void testGetEdgesStatusRequest()
+	protected void testGetEdgesStatusRequest()
 			throws URISyntaxException, InterruptedException, ExecutionException, OpenemsNamedException {
-		TestClient client = prepareTestClient();
+		var client = B2bWebsocketTest.prepareTestClient();
 
-		GetEdgesStatusRequest request = new GetEdgesStatusRequest();
+		var request = new GetEdgesStatusRequest();
 		try {
-			CompletableFuture responseFuture = client.sendRequest(request);
+			var responseFuture = client.sendRequest(request);
 			System.out.println(responseFuture.get().toString());
 		} catch (InterruptedException | ExecutionException | OpenemsNamedException e) {
 			System.out.println(e.getMessage());
@@ -56,15 +55,15 @@ public void testGetEdgesStatusRequest()
 	}
 
 	// @Test
-	public void testGetEdgesChannelsValuesRequest() throws URISyntaxException, InterruptedException {
-		TestClient client = prepareTestClient();
+	protected void testGetEdgesChannelsValuesRequest() throws URISyntaxException, InterruptedException {
+		var client = B2bWebsocketTest.prepareTestClient();
 
-		GetEdgesChannelsValuesRequest request = new GetEdgesChannelsValuesRequest();
+		var request = new GetEdgesChannelsValuesRequest();
 		request.addEdgeId("edge0");
 		request.addChannel(new ChannelAddress("_sum", "EssSoc"));
 		request.addChannel(new ChannelAddress("_sum", "ProductionActivePower"));
 		try {
-			CompletableFuture responseFuture = client.sendRequest(request);
+			var responseFuture = client.sendRequest(request);
 			System.out.println(responseFuture.get().toString());
 		} catch (InterruptedException | ExecutionException | OpenemsNamedException e) {
 			System.out.println(e.getMessage());
@@ -73,19 +72,19 @@ public void testGetEdgesChannelsValuesRequest() throws URISyntaxException, Inter
 	}
 
 	// @Test
-	public void testSubscribeEdgesChannelsRequest()
+	protected void testSubscribeEdgesChannelsRequest()
 			throws URISyntaxException, InterruptedException, ExecutionException, OpenemsNamedException {
-		TestClient client = prepareTestClient();
+		var client = B2bWebsocketTest.prepareTestClient();
 		client.setOnNotification((ws, notification) -> {
 			System.out.println(notification.toString());
 		});
 
-		SubscribeEdgesChannelsRequest request = new SubscribeEdgesChannelsRequest(0);
+		var request = new SubscribeEdgesChannelsRequest(0);
 		request.addEdgeId("edge0");
 		request.addChannel(new ChannelAddress("_sum", "EssSoc"));
 		request.addChannel(new ChannelAddress("_sum", "ProductionActivePower"));
 		try {
-			CompletableFuture responseFuture = client.sendRequest(request);
+			var responseFuture = client.sendRequest(request);
 			System.out.println(responseFuture.get().toString());
 		} catch (InterruptedException | ExecutionException | OpenemsNamedException e) {
 			System.out.println(e.getMessage());
@@ -95,16 +94,16 @@ public void testSubscribeEdgesChannelsRequest()
 		client.stop();
 	}
 
-//	@Test
-	public void testSetGridConnSchedule() throws URISyntaxException, InterruptedException {
-		TestClient client = prepareTestClient();
+	// @Test
+	protected void testSetGridConnSchedule() throws URISyntaxException, InterruptedException {
+		var client = B2bWebsocketTest.prepareTestClient();
 
-		SetGridConnScheduleRequest request = new SetGridConnScheduleRequest("edge0");
-		long now = System.currentTimeMillis() / 1000;
+		var request = new SetGridConnScheduleRequest("edge0");
+		var now = System.currentTimeMillis() / 1000;
 		request.addScheduleEntry(new GridConnSchedule(now, 60, 0));
 		// request.addScheduleEntry(new GridConnSchedule(now + 60, 60, -5000));
 		try {
-			CompletableFuture responseFuture = client.sendRequest(request);
+			var responseFuture = client.sendRequest(request);
 			System.out.println(responseFuture.get().toString());
 		} catch (InterruptedException | ExecutionException | OpenemsNamedException e) {
 			System.out.println(e.getMessage());
diff --git a/io.openems.backend.b2bwebsocket/test/io/openems/backend/b2bwebsocket/TestClient.java b/io.openems.backend.b2bwebsocket/test/io/openems/backend/b2bwebsocket/TestClient.java
index fd7a14ad926..ea09598672f 100644
--- a/io.openems.backend.b2bwebsocket/test/io/openems/backend/b2bwebsocket/TestClient.java
+++ b/io.openems.backend.b2bwebsocket/test/io/openems/backend/b2bwebsocket/TestClient.java
@@ -17,7 +17,7 @@
 
 public class TestClient extends AbstractWebsocketClient {
 
-	private Logger log = LoggerFactory.getLogger(TestClient.class);
+	private final Logger log = LoggerFactory.getLogger(TestClient.class);
 
 	private OnOpen onOpen;
 	private OnRequest onRequest;
@@ -28,26 +28,26 @@ public class TestClient extends AbstractWebsocketClient {
 	protected TestClient(URI serverUri, Map httpHeaders) {
 		super("B2bwebsocket.Unittest", serverUri, httpHeaders);
 		this.onOpen = (ws, handshake) -> {
-			log.info("OnOpen: " + handshake);
+			this.log.info("OnOpen: " + handshake);
 		};
 		this.onRequest = (ws, request) -> {
-			log.info("OnRequest: " + request);
+			this.log.info("OnRequest: " + request);
 			return null;
 		};
 		this.onNotification = (ws, notification) -> {
-			log.info("OnNotification: " + notification);
+			this.log.info("OnNotification: " + notification);
 		};
 		this.onError = (ws, ex) -> {
-			log.info("onError: " + ex.getMessage());
+			this.log.info("onError: " + ex.getMessage());
 		};
 		this.onClose = (ws, code, reason, remote) -> {
-			log.info("onClose: " + reason);
+			this.log.info("onClose: " + reason);
 		};
 	}
 
 	@Override
 	public OnOpen getOnOpen() {
-		return onOpen;
+		return this.onOpen;
 	}
 
 	public void setOnOpen(OnOpen onOpen) {
@@ -56,7 +56,7 @@ public void setOnOpen(OnOpen onOpen) {
 
 	@Override
 	public OnRequest getOnRequest() {
-		return onRequest;
+		return this.onRequest;
 	}
 
 	public void setOnRequest(OnRequest onRequest) {
@@ -65,7 +65,7 @@ public void setOnRequest(OnRequest onRequest) {
 
 	@Override
 	public OnError getOnError() {
-		return onError;
+		return this.onError;
 	}
 
 	public void setOnError(OnError onError) {
@@ -74,7 +74,7 @@ public void setOnError(OnError onError) {
 
 	@Override
 	public OnClose getOnClose() {
-		return onClose;
+		return this.onClose;
 	}
 
 	public void setOnClose(OnClose onClose) {
@@ -83,7 +83,7 @@ public void setOnClose(OnClose onClose) {
 
 	@Override
 	protected OnNotification getOnNotification() {
-		return onNotification;
+		return this.onNotification;
 	}
 
 	public void setOnNotification(OnNotification onNotification) {
diff --git a/io.openems.backend.common/src/io/openems/backend/common/component/AbstractOpenemsBackendComponent.java b/io.openems.backend.common/src/io/openems/backend/common/component/AbstractOpenemsBackendComponent.java
index 3579857fd7f..433c67a0846 100644
--- a/io.openems.backend.common/src/io/openems/backend/common/component/AbstractOpenemsBackendComponent.java
+++ b/io.openems.backend.common/src/io/openems/backend/common/component/AbstractOpenemsBackendComponent.java
@@ -9,7 +9,7 @@ public class AbstractOpenemsBackendComponent {
 
 	/**
 	 * Initializes the AbstractOpenemsBackendComponent.
-	 * 
+	 *
 	 * @param name a descriptive name for this component. Available via
 	 *             {@link #getName()}
 	 */
@@ -19,7 +19,7 @@ public AbstractOpenemsBackendComponent(String name) {
 
 	/**
 	 * A descriptive name for this component.
-	 * 
+	 *
 	 * @return the name
 	 */
 	public String getName() {
@@ -28,7 +28,7 @@ public String getName() {
 
 	/**
 	 * Log an info message including the Component ID.
-	 * 
+	 *
 	 * @param log     the Logger that is used for writing the log
 	 * @param message the Info-message
 	 */
@@ -38,7 +38,7 @@ protected void logInfo(Logger log, String message) {
 
 	/**
 	 * Log a warn message including the Component ID.
-	 * 
+	 *
 	 * @param log     the Logger that is used for writing the log
 	 * @param message the Warn-message
 	 */
@@ -48,7 +48,7 @@ protected void logWarn(Logger log, String message) {
 
 	/**
 	 * Log an error message including the Component ID.
-	 * 
+	 *
 	 * @param log     the Logger that is used for writing the log
 	 * @param message the Error-message
 	 */
@@ -58,7 +58,7 @@ protected void logError(Logger log, String message) {
 
 	/**
 	 * Log a debug message including the Component ID.
-	 * 
+	 *
 	 * @param log     the Logger that is used for writing the log
 	 * @param message the Debug-message
 	 */
diff --git a/io.openems.backend.common/src/io/openems/backend/common/edgewebsocket/EdgeWebsocket.java b/io.openems.backend.common/src/io/openems/backend/common/edgewebsocket/EdgeWebsocket.java
index 9418e2e6b44..c661efc99d8 100644
--- a/io.openems.backend.common/src/io/openems/backend/common/edgewebsocket/EdgeWebsocket.java
+++ b/io.openems.backend.common/src/io/openems/backend/common/edgewebsocket/EdgeWebsocket.java
@@ -17,7 +17,7 @@ public interface EdgeWebsocket {
 	/**
 	 * Send an authenticated JSON-RPC Request to an Edge via Websocket and expect a
 	 * JSON-RPC Response.
-	 * 
+	 *
 	 * @param edgeId  the Edge-ID
 	 * @param user    the authenticated {@link User}
 	 * @param request the {@link JsonrpcRequest}
@@ -29,7 +29,7 @@ public CompletableFuture send(String edgeId, User user,
 
 	/**
 	 * Send a JSON-RPC Notification to an Edge.
-	 * 
+	 *
 	 * @param edgeId       the Edge-ID
 	 * @param notification the JsonrpcNotification
 	 * @throws OpenemsNamedException on error
@@ -38,7 +38,7 @@ public CompletableFuture send(String edgeId, User user,
 
 	/**
 	 * Handles a {@link SubscribeSystemLogRequest}.
-	 * 
+	 *
 	 * @param edgeId  the Edge-ID
 	 * @param user    the {@link User}
 	 * @param token   the UI session token
diff --git a/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/JsonRpcRequestHandler.java b/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/JsonRpcRequestHandler.java
index 4a418c1a575..875fc9b39f9 100644
--- a/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/JsonRpcRequestHandler.java
+++ b/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/JsonRpcRequestHandler.java
@@ -11,7 +11,7 @@ public interface JsonRpcRequestHandler {
 
 	/**
 	 * Handles a JSON-RPC Request.
-	 * 
+	 *
 	 * @param context the Logger context, i.e. the name of the parent source
 	 * @param user    the User
 	 * @param request the JsonrpcRequest
diff --git a/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/AddEdgeToUserRequest.java b/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/AddEdgeToUserRequest.java
index 8d38068a7ac..c0f38201189 100644
--- a/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/AddEdgeToUserRequest.java
+++ b/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/AddEdgeToUserRequest.java
@@ -8,7 +8,7 @@
 
 /**
  * Adds a Edge to a User.
- * 
+ *
  * 
  * {
  *   "jsonrpc": "2.0",
@@ -26,26 +26,26 @@ public class AddEdgeToUserRequest extends JsonrpcRequest {
 
 	/**
 	 * Create {@link AddEdgeToUserRequest} from a template {@link JsonrpcRequest}.
-	 * 
+	 *
 	 * @param r the template {@link JsonrpcRequest}
 	 * @return the {@link AddEdgeToUserRequest}
 	 * @throws OpenemsNamedException on parse error
 	 */
 	public static AddEdgeToUserRequest from(JsonrpcRequest r) throws OpenemsNamedException {
-		JsonObject p = r.getParams();
-		String setupPassword = JsonUtils.getAsString(p, "setupPassword");
+		var p = r.getParams();
+		var setupPassword = JsonUtils.getAsString(p, "setupPassword");
 		return new AddEdgeToUserRequest(r, setupPassword);
 	}
 
 	private final String setupPassword;
 
 	public AddEdgeToUserRequest(String setupPassword) {
-		super(METHOD);
+		super(AddEdgeToUserRequest.METHOD);
 		this.setupPassword = setupPassword;
 	}
 
 	private AddEdgeToUserRequest(JsonrpcRequest request, String setupPassword) {
-		super(request, METHOD);
+		super(request, AddEdgeToUserRequest.METHOD);
 		this.setupPassword = setupPassword;
 	}
 
diff --git a/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/GetEdgesChannelsValuesRequest.java b/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/GetEdgesChannelsValuesRequest.java
index f269612d9b9..557df13c06f 100644
--- a/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/GetEdgesChannelsValuesRequest.java
+++ b/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/GetEdgesChannelsValuesRequest.java
@@ -13,7 +13,7 @@
 
 /**
  * Represents a JSON-RPC Request for 'getChannelsValues'.
- * 
+ *
  * 
  * {
  *   "jsonrpc": "2.0",
@@ -33,21 +33,21 @@ public class GetEdgesChannelsValuesRequest extends JsonrpcRequest {
 	/**
 	 * Create {@link GetEdgesChannelsValuesRequest} from a template
 	 * {@link JsonrpcRequest}.
-	 * 
+	 *
 	 * @param r the template {@link JsonrpcRequest}
 	 * @return the {@link GetEdgesChannelsValuesRequest}
 	 * @throws OpenemsNamedException on parse error
 	 */
 	public static GetEdgesChannelsValuesRequest from(JsonrpcRequest r) throws OpenemsNamedException {
-		JsonObject p = r.getParams();
-		GetEdgesChannelsValuesRequest result = new GetEdgesChannelsValuesRequest(r);
-		JsonArray edgeIds = JsonUtils.getAsJsonArray(p, "ids");
+		var p = r.getParams();
+		var result = new GetEdgesChannelsValuesRequest(r);
+		var edgeIds = JsonUtils.getAsJsonArray(p, "ids");
 		for (JsonElement edgeId : edgeIds) {
 			result.addEdgeId(JsonUtils.getAsString(edgeId));
 		}
-		JsonArray channels = JsonUtils.getAsJsonArray(p, "channels");
+		var channels = JsonUtils.getAsJsonArray(p, "channels");
 		for (JsonElement channel : channels) {
-			ChannelAddress address = ChannelAddress.fromString(JsonUtils.getAsString(channel));
+			var address = ChannelAddress.fromString(JsonUtils.getAsString(channel));
 			result.addChannel(address);
 		}
 		return result;
@@ -57,16 +57,16 @@ public static GetEdgesChannelsValuesRequest from(JsonrpcRequest r) throws Openem
 	private final TreeSet channels = new TreeSet<>();
 
 	public GetEdgesChannelsValuesRequest() {
-		super(METHOD);
+		super(GetEdgesChannelsValuesRequest.METHOD);
 	}
 
 	private GetEdgesChannelsValuesRequest(JsonrpcRequest request) {
-		super(request, METHOD);
+		super(request, GetEdgesChannelsValuesRequest.METHOD);
 	}
 
 	/**
 	 * Adds a Edge-ID.
-	 * 
+	 *
 	 * @param edgeId the Edge-ID
 	 */
 	public void addEdgeId(String edgeId) {
@@ -75,7 +75,7 @@ public void addEdgeId(String edgeId) {
 
 	/**
 	 * Gets the Edge-IDs.
-	 * 
+	 *
 	 * @return set of Edge-IDs.
 	 */
 	public TreeSet getEdgeIds() {
@@ -84,7 +84,7 @@ public TreeSet getEdgeIds() {
 
 	/**
 	 * Adds a {@link ChannelAddress}.
-	 * 
+	 *
 	 * @param address the {@link ChannelAddress}
 	 */
 	public void addChannel(ChannelAddress address) {
@@ -93,7 +93,7 @@ public void addChannel(ChannelAddress address) {
 
 	/**
 	 * Gets the {@link ChannelAddress}es.
-	 * 
+	 *
 	 * @return the {@link ChannelAddress}es
 	 */
 	public TreeSet getChannels() {
@@ -102,11 +102,11 @@ public TreeSet getChannels() {
 
 	@Override
 	public JsonObject getParams() {
-		JsonArray edgeIds = new JsonArray();
+		var edgeIds = new JsonArray();
 		for (String edgeId : this.edgeIds) {
 			edgeIds.add(edgeId);
 		}
-		JsonArray channels = new JsonArray();
+		var channels = new JsonArray();
 		for (ChannelAddress address : this.channels) {
 			channels.add(address.toString());
 		}
diff --git a/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/GetEdgesStatusRequest.java b/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/GetEdgesStatusRequest.java
index e5f763aaa1c..2c58f519a1c 100644
--- a/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/GetEdgesStatusRequest.java
+++ b/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/GetEdgesStatusRequest.java
@@ -8,7 +8,7 @@
 
 /**
  * Represents a JSON-RPC Request for 'getEdgesStatus'.
- * 
+ *
  * 
  * {
  *   "jsonrpc": "2.0",
@@ -24,7 +24,7 @@ public class GetEdgesStatusRequest extends JsonrpcRequest {
 
 	/**
 	 * Create {@link GetEdgesStatusRequest} from a template {@link JsonrpcRequest}.
-	 * 
+	 *
 	 * @param r the template {@link JsonrpcRequest}
 	 * @return the {@link GetEdgesStatusRequest}
 	 * @throws OpenemsNamedException on parse error
@@ -34,11 +34,11 @@ public static GetEdgesStatusRequest from(JsonrpcRequest r) throws OpenemsExcepti
 	}
 
 	public GetEdgesStatusRequest() {
-		super(METHOD);
+		super(GetEdgesStatusRequest.METHOD);
 	}
 
 	private GetEdgesStatusRequest(JsonrpcRequest request) {
-		super(request, METHOD);
+		super(request, GetEdgesStatusRequest.METHOD);
 	}
 
 	@Override
diff --git a/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/GetSetupProtocolRequest.java b/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/GetSetupProtocolRequest.java
index 49d4951c965..aaf4dbb4d89 100644
--- a/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/GetSetupProtocolRequest.java
+++ b/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/GetSetupProtocolRequest.java
@@ -13,12 +13,12 @@ public class GetSetupProtocolRequest extends JsonrpcRequest {
 	/**
 	 * Create {@link GetSetupProtocolRequest} from a template
 	 * {@link JsonrpcRequest}.
-	 * 
+	 *
 	 * @param request the template {@link JsonrpcRequest}
 	 * @return Created {@link GetSetupProtocolRequest}
 	 */
 	public static GetSetupProtocolRequest from(JsonrpcRequest request) throws OpenemsNamedException {
-		JsonObject params = request.getParams();
+		var params = request.getParams();
 
 		return new GetSetupProtocolRequest(request, JsonUtils.getAsInt(params, "setupProtocolId"));
 	}
@@ -26,7 +26,7 @@ public static GetSetupProtocolRequest from(JsonrpcRequest request) throws Openem
 	private final int setupProtocolId;
 
 	private GetSetupProtocolRequest(JsonrpcRequest request, int setupProtocolId) {
-		super(request, METHOD);
+		super(request, GetSetupProtocolRequest.METHOD);
 		this.setupProtocolId = setupProtocolId;
 	}
 
@@ -39,7 +39,7 @@ public JsonObject getParams() {
 
 	/**
 	 * Gets the Setup Protocol ID.
-	 * 
+	 *
 	 * @return the Setup Protocol ID
 	 */
 	public int getSetupProtocolId() {
diff --git a/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/GetUserInformationRequest.java b/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/GetUserInformationRequest.java
index 31b824c1a37..8c70f547b0c 100644
--- a/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/GetUserInformationRequest.java
+++ b/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/GetUserInformationRequest.java
@@ -6,7 +6,7 @@
 
 /**
  * Gets the User Information.
- * 
+ *
  * 
  * {
  *   "jsonrpc": "2.0",
@@ -23,7 +23,7 @@ public class GetUserInformationRequest extends JsonrpcRequest {
 	/**
 	 * Create {@link GetUserInformationRequest} from a template
 	 * {@link JsonrpcRequest}.
-	 * 
+	 *
 	 * @param request the template {@link JsonrpcRequest}
 	 * @return Created {@link GetUserInformationRequest}
 	 */
@@ -32,7 +32,7 @@ public static GetUserInformationRequest from(JsonrpcRequest request) {
 	}
 
 	private GetUserInformationRequest(JsonrpcRequest request) {
-		super(request, METHOD);
+		super(request, GetUserInformationRequest.METHOD);
 	}
 
 	@Override
diff --git a/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/RegisterUserRequest.java b/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/RegisterUserRequest.java
index 3adf0d3b58c..a1f1dd1f35a 100644
--- a/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/RegisterUserRequest.java
+++ b/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/RegisterUserRequest.java
@@ -12,12 +12,12 @@ public class RegisterUserRequest extends JsonrpcRequest {
 
 	/**
 	 * Create {@link RegisterUserRequest} from a template {@link JsonrpcRequest}.
-	 * 
+	 *
 	 * @param request the template {@link JsonrpcRequest}
 	 * @return Created {@link RegisterUserRequest}
 	 */
 	public static RegisterUserRequest from(JsonrpcRequest request) throws OpenemsNamedException {
-		JsonObject params = request.getParams();
+		var params = request.getParams();
 
 		return new RegisterUserRequest(request, JsonUtils.getAsJsonObject(params, "user"));
 	}
@@ -25,7 +25,7 @@ public static RegisterUserRequest from(JsonrpcRequest request) throws OpenemsNam
 	private final JsonObject jsonObject;
 
 	private RegisterUserRequest(JsonrpcRequest request, JsonObject jsonObject) {
-		super(request, METHOD);
+		super(request, RegisterUserRequest.METHOD);
 		this.jsonObject = jsonObject;
 	}
 
@@ -36,7 +36,7 @@ public JsonObject getParams() {
 
 	/**
 	 * Gets the User Registration information as {@link JsonObject}.
-	 * 
+	 *
 	 * @return the {@link JsonObject}
 	 */
 	public JsonObject getJsonObject() {
diff --git a/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/SetUserInformationRequest.java b/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/SetUserInformationRequest.java
index 8b28ce227dd..e5504cef444 100644
--- a/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/SetUserInformationRequest.java
+++ b/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/SetUserInformationRequest.java
@@ -8,7 +8,7 @@
 
 /**
  * Sets the User Information.
- * 
+ *
  * 
  * {
  *   "jsonrpc": "2.0",
@@ -41,13 +41,13 @@ public class SetUserInformationRequest extends JsonrpcRequest {
 	/**
 	 * Create {@link SetUserInformationRequest} from a template
 	 * {@link JsonrpcRequest}.
-	 * 
+	 *
 	 * @param request the template {@link JsonrpcRequest}
 	 * @return Created {@link SetUserInformationRequest}
 	 * @throws OpenemsNamedException on parse error
 	 */
 	public static SetUserInformationRequest from(JsonrpcRequest request) throws OpenemsNamedException {
-		JsonObject params = request.getParams();
+		var params = request.getParams();
 
 		return new SetUserInformationRequest(request, JsonUtils.getAsJsonObject(params, "user"));
 	}
@@ -55,7 +55,7 @@ public static SetUserInformationRequest from(JsonrpcRequest request) throws Open
 	private final JsonObject jsonObject;
 
 	private SetUserInformationRequest(JsonrpcRequest request, JsonObject jsonObject) {
-		super(request, METHOD);
+		super(request, SetUserInformationRequest.METHOD);
 		this.jsonObject = jsonObject;
 	}
 
@@ -66,7 +66,7 @@ public JsonObject getParams() {
 
 	/**
 	 * Gets the User Information as {@link JsonObject}.
-	 * 
+	 *
 	 * @return the {@link JsonObject}
 	 */
 	public JsonObject getJsonObject() {
diff --git a/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/SubmitSetupProtocolRequest.java b/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/SubmitSetupProtocolRequest.java
index 13c27d7f46e..679f563f266 100644
--- a/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/SubmitSetupProtocolRequest.java
+++ b/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/request/SubmitSetupProtocolRequest.java
@@ -8,7 +8,7 @@
 
 /**
  * Submits the Setup Protocol.
- * 
+ *
  * 
  * {
  *   "jsonrpc": "2.0",
@@ -18,7 +18,7 @@
  *     "protocol": {
  *       "edge": {
  *         "id": string
- *       }, 
+ *       },
  *       "customer": {
  *         "firstname": string,
  *         "lastname": string,
@@ -71,20 +71,20 @@ public class SubmitSetupProtocolRequest extends JsonrpcRequest {
 	/**
 	 * Create {@link SubmitSetupProtocolRequest} from a template
 	 * {@link JsonrpcRequest}.
-	 * 
+	 *
 	 * @param request the template {@link JsonrpcRequest}
 	 * @return Created {@link SubmitSetupProtocolRequest}
 	 * @throws OpenemsNamedException on parse error
 	 */
 	public static SubmitSetupProtocolRequest from(JsonrpcRequest request) throws OpenemsNamedException {
-		JsonObject params = request.getParams();
+		var params = request.getParams();
 		return new SubmitSetupProtocolRequest(request, JsonUtils.getAsJsonObject(params, "protocol"));
 	}
 
 	private final JsonObject jsonObject;
 
 	private SubmitSetupProtocolRequest(JsonrpcRequest request, JsonObject jsonObject) {
-		super(request, METHOD);
+		super(request, SubmitSetupProtocolRequest.METHOD);
 		this.jsonObject = jsonObject;
 	}
 
@@ -95,7 +95,7 @@ public JsonObject getParams() {
 
 	/**
 	 * Gets the Setup Protocol information as {@link JsonObject}.
-	 * 
+	 *
 	 * @return the {@link JsonObject}
 	 */
 	public JsonObject getJsonObject() {
diff --git a/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/response/AddEdgeToUserResponse.java b/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/response/AddEdgeToUserResponse.java
index 30ce30a1c3b..05045d53474 100644
--- a/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/response/AddEdgeToUserResponse.java
+++ b/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/response/AddEdgeToUserResponse.java
@@ -11,7 +11,7 @@
 
 /**
  * Represents a JSON-RPC Response for {@link AddEdgeToUserRequest}.
- * 
+ *
  * 
  * {
  *   "jsonrpc": "2.0",
@@ -34,7 +34,7 @@ public AddEdgeToUserResponse(UUID id, Edge edge) {
 		super(id);
 		this.edge = edge;
 	}
-	
+
 	@Override
 	public JsonObject getResult() {
 		return JsonUtils.buildJsonObject() //
diff --git a/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/response/GetEdgesChannelsValuesResponse.java b/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/response/GetEdgesChannelsValuesResponse.java
index b0f46c0ab7e..6e4b8544af6 100644
--- a/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/response/GetEdgesChannelsValuesResponse.java
+++ b/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/response/GetEdgesChannelsValuesResponse.java
@@ -15,7 +15,7 @@
 
 /**
  * Represents a JSON-RPC Response for {@link GetEdgesChannelsValuesRequest}.
- * 
+ *
  * 
  * {
  *   "jsonrpc": "2.0",
@@ -42,7 +42,7 @@ public GetEdgesChannelsValuesResponse(UUID id) {
 
 	/**
 	 * Adds a Value to the JSON-RPC Response.
-	 * 
+	 *
 	 * @param edgeId  the Edge-ID
 	 * @param channel the {@link ChannelAddress}
 	 * @param value   the value
@@ -53,11 +53,11 @@ public void addValue(String edgeId, ChannelAddress channel, JsonElement value) {
 
 	@Override
 	public JsonObject getResult() {
-		JsonObject j = new JsonObject();
+		var j = new JsonObject();
 		for (Entry> row : this.values.rowMap().entrySet()) {
 			String edgeId = row.getKey();
 			Map columns = row.getValue();
-			JsonObject jEdge = new JsonObject();
+			var jEdge = new JsonObject();
 			for (Entry column : columns.entrySet()) {
 				ChannelAddress channel = column.getKey();
 				JsonElement value = column.getValue();
diff --git a/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/response/GetEdgesStatusResponse.java b/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/response/GetEdgesStatusResponse.java
index 3e63200a0cb..7680bf570b9 100644
--- a/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/response/GetEdgesStatusResponse.java
+++ b/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/response/GetEdgesStatusResponse.java
@@ -12,7 +12,7 @@
 
 /**
  * Represents a JSON-RPC Response for {@link GetEdgesStatusRequest}.
- * 
+ *
  * 
  * {
  *   "jsonrpc": "2.0",
@@ -51,7 +51,7 @@ public GetEdgesStatusResponse(UUID id, Map edgeInfos) {
 
 	@Override
 	public JsonObject getResult() {
-		JsonObject j = new JsonObject();
+		var j = new JsonObject();
 		for (Entry entry : this.edgeInfos.entrySet()) {
 			EdgeInfo edge = entry.getValue();
 			j.add(entry.getKey(), JsonUtils.buildJsonObject() //
diff --git a/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/response/GetUserInformationResponse.java b/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/response/GetUserInformationResponse.java
index 67564d25451..5ce64b7e5ce 100644
--- a/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/response/GetUserInformationResponse.java
+++ b/io.openems.backend.common/src/io/openems/backend/common/jsonrpc/response/GetUserInformationResponse.java
@@ -12,7 +12,7 @@
 
 /**
  * Represents a JSON-RPC Response for {@link GetUserInformationRequest}.
- * 
+ *
  * 
  * {
  *   "jsonrpc": "2.0",
@@ -48,7 +48,7 @@ public GetUserInformationResponse(UUID id, Map userInformation)
 
 	@Override
 	public JsonObject getResult() {
-		JsonObject companyJson = JsonUtils.buildJsonObject() //
+		var companyJson = JsonUtils.buildJsonObject() //
 				.addProperty("name", ObjectUtils.getAsString(this.userInformation.get("commercial_company_name"))) //
 				.build();
 
@@ -58,14 +58,14 @@ public JsonObject getResult() {
 			country = ObjectUtils.getAsString(array[2]).toLowerCase();
 		}
 
-		JsonObject addressJson = JsonUtils.buildJsonObject() //
+		var addressJson = JsonUtils.buildJsonObject() //
 				.addProperty("street", ObjectUtils.getAsString(this.userInformation.get("street"))) //
 				.addProperty("zip", ObjectUtils.getAsString(this.userInformation.get("zip"))) //
 				.addProperty("city", ObjectUtils.getAsString(this.userInformation.get("city"))) //
 				.addProperty("country", country) //
 				.build();
 
-		JsonObject userJson = JsonUtils.buildJsonObject() //
+		var userJson = JsonUtils.buildJsonObject() //
 				.addProperty("firstname", ObjectUtils.getAsString(this.userInformation.get("firstname"))) //
 				.addProperty("lastname", ObjectUtils.getAsString(this.userInformation.get("lastname"))) //
 				.addProperty("email", ObjectUtils.getAsString(this.userInformation.get("email"))) //
diff --git a/io.openems.backend.common/src/io/openems/backend/common/metadata/AbstractMetadata.java b/io.openems.backend.common/src/io/openems/backend/common/metadata/AbstractMetadata.java
index 0fb4af2c6ff..7e6c3d6f0b6 100644
--- a/io.openems.backend.common/src/io/openems/backend/common/metadata/AbstractMetadata.java
+++ b/io.openems.backend.common/src/io/openems/backend/common/metadata/AbstractMetadata.java
@@ -10,7 +10,7 @@ public abstract class AbstractMetadata extends AbstractOpenemsBackendComponent i
 
 	/**
 	 * Initializes the AbstractMetadata.
-	 * 
+	 *
 	 * @param name a descriptive name for this component. Available via
 	 *             {@link #getName()}
 	 */
diff --git a/io.openems.backend.common/src/io/openems/backend/common/metadata/Edge.java b/io.openems.backend.common/src/io/openems/backend/common/metadata/Edge.java
index 3f0bfd94f44..012a510e375 100644
--- a/io.openems.backend.common/src/io/openems/backend/common/metadata/Edge.java
+++ b/io.openems.backend.common/src/io/openems/backend/common/metadata/Edge.java
@@ -66,6 +66,11 @@ public EdgeConfig getConfig() {
 		return this.config;
 	}
 
+	/**
+	 * Gets this {@link Edge} as {@link JsonObject}.
+	 * 
+	 * @return a {@link JsonObject}
+	 */
 	public JsonObject toJsonObject() {
 		return JsonUtils.buildJsonObject() //
 				.addProperty("id", this.id) //
@@ -78,10 +83,17 @@ public JsonObject toJsonObject() {
 
 	@Override
 	public String toString() {
-		return "Edge [id=" + id + ", comment=" + comment + ", state=" + state + ", version=" + version
-				+ ", producttype=" + producttype + ", deprecatedConfig="
-				+ (config.toString().isEmpty() ? "NOT_SET" : "set") + ", lastMessage=" + lastMessage + ", lastUpdate="
-				+ lastUpdate + ", isOnline=" + isOnline + "]";
+		return "Edge [" //
+				+ "id=" + this.id + ", " //
+				+ "comment=" + this.comment + ", " //
+				+ "state=" + this.state + ", " //
+				+ "version=" + this.version + ", " //
+				+ "producttype=" + this.producttype + ", " //
+				+ "deprecatedConfig=" + (this.config.toString().isEmpty() ? "NOT_SET" : "set") + ", " //
+				+ "lastMessage=" + this.lastMessage + ", " //
+				+ "lastUpdate=" + this.lastUpdate + ", " //
+				+ "isOnline=" + this.isOnline //
+				+ "]";
 	}
 
 	/*
@@ -89,6 +101,11 @@ public String toString() {
 	 */
 	private final List> onSetOnline = new CopyOnWriteArrayList<>();
 
+	/**
+	 * Add a Listener for Set-Online events.
+	 * 
+	 * @param listener the listener
+	 */
 	public void onSetOnline(Consumer listener) {
 		this.onSetOnline.add(listener);
 	}
@@ -99,7 +116,7 @@ public boolean isOnline() {
 
 	/**
 	 * Marks this Edge as being online. This is called by an event listener.
-	 * 
+	 *
 	 * @param isOnline true if the Edge is online
 	 */
 	public synchronized void setOnline(boolean isOnline) {
@@ -115,7 +132,7 @@ public synchronized void setOnline(boolean isOnline) {
 	/**
 	 * Adds a listener for reception of new EdgeConfig. The listener is called
 	 * before the new config is applied.
-	 * 
+	 *
 	 * @param listener the Listener
 	 */
 	public void onSetConfig(Consumer listener) {
@@ -124,7 +141,7 @@ public void onSetConfig(Consumer listener) {
 
 	/**
 	 * Sets the configuration for this Edge and calls the SetConfig-Listeners.
-	 * 
+	 *
 	 * @param config the configuration
 	 */
 	public synchronized void setConfig(EdgeConfig config) {
@@ -133,7 +150,7 @@ public synchronized void setConfig(EdgeConfig config) {
 
 	/**
 	 * Sets the configuration for this Edge.
-	 * 
+	 *
 	 * @param config        the configuration
 	 * @param callListeners whether to call the SetConfig-Listeners
 	 */
@@ -160,6 +177,11 @@ public State getState() {
 	 */
 	private final List onSetLastMessageTimestamp = new CopyOnWriteArrayList<>();
 
+	/**
+	 * Add a Listener for Set-Last-Message events.
+	 * 
+	 * @param listener the listener
+	 */
 	public void onSetLastMessage(Runnable listener) {
 		this.onSetLastMessageTimestamp.add(listener);
 	}
@@ -173,14 +195,14 @@ public synchronized void setLastMessageTimestamp() {
 
 	/**
 	 * Sets the Last-Message-Timestamp.
-	 * 
+	 *
 	 * @param callListeners whether to call the SetLastMessage-Listeners
 	 */
 	public synchronized void setLastMessageTimestamp(boolean callListeners) {
 		if (callListeners) {
-			this.onSetLastMessageTimestamp.forEach(listener -> listener.run());
+			this.onSetLastMessageTimestamp.forEach(Runnable::run);
 		}
-		ZonedDateTime now = ZonedDateTime.now(ZoneOffset.UTC);
+		var now = ZonedDateTime.now(ZoneOffset.UTC);
 		this.lastMessage = now;
 	}
 
@@ -193,6 +215,11 @@ public ZonedDateTime getLastMessageTimestamp() {
 	 */
 	private final List onSetLastUpdateTimestamp = new CopyOnWriteArrayList<>();
 
+	/**
+	 * Add a Listener for Set-Last-Update events.
+	 * 
+	 * @param listener the listener
+	 */
 	public void onSetLastUpdate(Runnable listener) {
 		this.onSetLastUpdateTimestamp.add(listener);
 	}
@@ -206,14 +233,14 @@ public synchronized void setLastUpdateTimestamp() {
 
 	/**
 	 * Sets the Last-Update-Timestamp.
-	 * 
+	 *
 	 * @param callListeners whether to call the SetLastUpdate-Listeners
 	 */
 	public synchronized void setLastUpdateTimestamp(boolean callListeners) {
 		if (callListeners) {
-			this.onSetLastUpdateTimestamp.forEach(listener -> listener.run());
+			this.onSetLastUpdateTimestamp.forEach(Runnable::run);
 		}
-		ZonedDateTime now = ZonedDateTime.now(ZoneOffset.UTC);
+		var now = ZonedDateTime.now(ZoneOffset.UTC);
 		this.lastUpdate = now;
 	}
 
@@ -230,13 +257,18 @@ public SemanticVersion getVersion() {
 
 	private final List> onSetVersion = new CopyOnWriteArrayList<>();
 
+	/**
+	 * Add a Listener for Set-Version events.
+	 * 
+	 * @param listener the listener
+	 */
 	public void onSetVersion(Consumer listener) {
 		this.onSetVersion.add(listener);
 	}
 
 	/**
 	 * Sets the version and calls the SetVersion-Listeners.
-	 * 
+	 *
 	 * @param version the version
 	 */
 	public synchronized void setVersion(SemanticVersion version) {
@@ -245,7 +277,7 @@ public synchronized void setVersion(SemanticVersion version) {
 
 	/**
 	 * Sets the version.
-	 * 
+	 *
 	 * @param version       the version
 	 * @param callListeners whether to call the SetVersion-Listeners
 	 */
@@ -269,13 +301,18 @@ public String getProducttype() {
 
 	private final List> onSetProducttype = new CopyOnWriteArrayList<>();
 
+	/**
+	 * Add a Listener for Set-Product-Type events.
+	 * 
+	 * @param listener the listener
+	 */
 	public void onSetProducttype(Consumer listener) {
 		this.onSetProducttype.add(listener);
 	}
 
 	/**
 	 * Sets the Producttype and calls the SetProducttype-Listeners.
-	 * 
+	 *
 	 * @param producttype the Producttype
 	 */
 	public synchronized void setProducttype(String producttype) {
@@ -284,7 +321,7 @@ public synchronized void setProducttype(String producttype) {
 
 	/**
 	 * Sets the Producttype.
-	 * 
+	 *
 	 * @param producttype   the Producttype
 	 * @param callListeners whether to call the SetProducttype-Listeners
 	 */
@@ -308,13 +345,18 @@ public Level getSumState() {
 
 	private final List> onSetSumState = new CopyOnWriteArrayList<>();
 
+	/**
+	 * Add a Listener for Set-Sum-State events.
+	 * 
+	 * @param listener the listener
+	 */
 	public void onSetSumState(Consumer listener) {
 		this.onSetSumState.add(listener);
 	}
 
 	/**
 	 * Sets the sumState and calls the SetSumState-Listeners.
-	 * 
+	 *
 	 * @param sumState the sumState
 	 */
 	public synchronized void setSumState(Level sumState) {
@@ -323,7 +365,7 @@ public synchronized void setSumState(Level sumState) {
 
 	/**
 	 * Sets the version.
-	 * 
+	 *
 	 * @param sumState      the sumState
 	 * @param callListeners whether to call the SetSumState-Listeners
 	 */
diff --git a/io.openems.backend.common/src/io/openems/backend/common/metadata/Metadata.java b/io.openems.backend.common/src/io/openems/backend/common/metadata/Metadata.java
index abac6f29180..47033b1fa42 100644
--- a/io.openems.backend.common/src/io/openems/backend/common/metadata/Metadata.java
+++ b/io.openems.backend.common/src/io/openems/backend/common/metadata/Metadata.java
@@ -15,8 +15,8 @@
 import io.openems.common.channel.Level;
 import io.openems.common.exceptions.OpenemsError;
 import io.openems.common.exceptions.OpenemsError.OpenemsNamedException;
-import io.openems.common.jsonrpc.request.UpdateUserLanguageRequest.Language;
 import io.openems.common.exceptions.OpenemsException;
+import io.openems.common.jsonrpc.request.UpdateUserLanguageRequest.Language;
 import io.openems.common.types.ChannelAddress;
 import io.openems.common.types.EdgeConfig;
 import io.openems.common.types.EdgeConfig.Component.Channel;
@@ -28,32 +28,32 @@ public interface Metadata {
 
 	/**
 	 * Was the Metadata service fully initialized?.
-	 * 
+	 *
 	 * 

 	 * The service might take some time in the beginning to establish a connection
 	 * or to cache data from an external database.
-	 * 
+	 *
 	 * @return true if it is initialized
 	 */
 	public boolean isInitialized();
 
 	/**
 	 * See {@link #isInitialized()}.
-	 * 
+	 *
 	 * @param callback the callback on 'isInitialized'
 	 */
 	public void addOnIsInitializedListener(Runnable callback);
 
 	/**
 	 * See {@link #isInitialized()}.
-	 * 
+	 *
 	 * @param callback the callback on 'isInitialized'
 	 */
 	public void removeOnIsInitializedListener(Runnable callback);
 
 	/**
 	 * Authenticates the User by username and password.
-	 * 
+	 *
 	 * @param username the Username
 	 * @param password the Password
 	 * @return the {@link User}
@@ -63,7 +63,7 @@ public interface Metadata {
 
 	/**
 	 * Authenticates the User by a Token.
-	 * 
+	 *
 	 * @param token the Token
 	 * @return the {@link User}
 	 * @throws OpenemsNamedException on error
@@ -72,14 +72,14 @@ public interface Metadata {
 
 	/**
 	 * Closes a session for a User.
-	 * 
+	 *
 	 * @param user the {@link User}
 	 */
 	public void logout(User user);
 
 	/**
 	 * Gets the Edge-ID for an API-Key, i.e. authenticates the API-Key.
-	 * 
+	 *
 	 * @param apikey the API-Key
 	 * @return the Edge-ID or Empty
 	 */
@@ -87,7 +87,7 @@ public interface Metadata {
 
 	/**
 	 * Get an Edge by its unique Edge-ID.
-	 * 
+	 *
 	 * @param edgeId the Edge-ID
 	 * @return the Edge as Optional
 	 */
@@ -96,23 +96,22 @@ public interface Metadata {
 	/**
 	 * Get an Edge by its unique Edge-ID. Throws an Exception if there is no Edge
 	 * with this ID.
-	 * 
+	 *
 	 * @param edgeId the Edge-ID
 	 * @return the Edge
 	 * @throws OpenemsException on error
 	 */
 	public default Edge getEdgeOrError(String edgeId) throws OpenemsException {
-		Optional edgeOpt = this.getEdge(edgeId);
+		var edgeOpt = this.getEdge(edgeId);
 		if (edgeOpt.isPresent()) {
 			return edgeOpt.get();
-		} else {
-			throw new OpenemsException("Unable to get Edge for id [" + edgeId + "]");
 		}
+		throw new OpenemsException("Unable to get Edge for id [" + edgeId + "]");
 	}
 
 	/**
 	 * Get an Edge by Edge-SetupPassword.
-	 * 
+	 *
 	 * @param setupPassword to find Edge
 	 * @return Edge as a Optional
 	 */
@@ -120,7 +119,7 @@ public default Edge getEdgeOrError(String edgeId) throws OpenemsException {
 
 	/**
 	 * Gets the User for the given User-ID.
-	 * 
+	 *
 	 * @param userId the User-ID
 	 * @return the {@link User}, or Empty
 	 */
@@ -128,29 +127,29 @@ public default Edge getEdgeOrError(String edgeId) throws OpenemsException {
 
 	/**
 	 * Gets all Edges.
-	 * 
+	 *
 	 * @return collection of Edges.
 	 */
 	public abstract Collection getAllEdges();
 
 	/**
 	 * Assigns Edge with given setupPassword to the logged in user and returns it.
-	 * 
+	 *
 	 * 

 	 * If the setupPassword is invalid, an OpenemsNamedException is thrown.
-	 * 
+	 *
 	 * @param user          the {@link User}
 	 * @param setupPassword the Setup-Password
 	 * @return the Edge for the given Setup-Password
 	 * @throws OpenemsNamedException on error
 	 */
 	public default Edge addEdgeToUser(User user, String setupPassword) throws OpenemsNamedException {
-		Optional optEdge = this.getEdgeBySetupPassword(setupPassword);
-		if (!optEdge.isPresent()) {
+		var edgeOpt = this.getEdgeBySetupPassword(setupPassword);
+		if (!edgeOpt.isPresent()) {
 			throw OpenemsError.COMMON_AUTHENTICATION_FAILED.exception();
 		}
 
-		Edge edge = optEdge.get();
+		var edge = edgeOpt.get();
 		this.addEdgeToUser(user, edge);
 
 		return edge;
@@ -158,10 +157,10 @@ public default Edge addEdgeToUser(User user, String setupPassword) throws Openem
 
 	/**
 	 * Assigns Edge to current user.
-	 * 
+	 *
 	 * 

 	 * If assignment fails, an OpenemsNamedException is thrown.
-	 * 
+	 *
 	 * @param user The {@link User}
 	 * @param edge The {@link Edge}
 	 *
@@ -171,7 +170,7 @@ public default Edge addEdgeToUser(User user, String setupPassword) throws Openem
 
 	/**
 	 * Helper method for creating a String of all active State-Channels by Level.
-	 * 
+	 *
 	 * @param activeStateChannels Map of ChannelAddress and
 	 *                            EdgeConfig.Component.Channel; as returned by
 	 *                            Edge.onSetSumState()
@@ -180,11 +179,11 @@ public default Edge addEdgeToUser(User user, String setupPassword) throws Openem
 	public static String activeStateChannelsToString(
 			Map activeStateChannels) {
 		// Sort active State-Channels by Level and Component-ID
-		HashMap> states = new HashMap<>();
+		var states = new HashMap>();
 		for (Entry entry : activeStateChannels.entrySet()) {
 			ChannelDetail detail = entry.getValue().getDetail();
 			if (detail instanceof ChannelDetailState) {
-				Level level = ((ChannelDetailState) detail).getLevel();
+				var level = ((ChannelDetailState) detail).getLevel();
 				HashMultimap channelsByComponent = states.get(level);
 				if (channelsByComponent == null) {
 					channelsByComponent = HashMultimap.create();
@@ -195,15 +194,15 @@ public static String activeStateChannelsToString(
 						entry.getValue());
 			}
 		}
-		StringBuilder result = new StringBuilder();
+		var result = new StringBuilder();
 		for (Level level : Level.values()) {
-			HashMultimap channelsByComponent = states.get(level);
+			var channelsByComponent = states.get(level);
 			if (channelsByComponent != null) {
 				if (result.length() > 0) {
 					result.append("| ");
 				}
 				result.append(level.name() + ": ");
-				StringBuilder subResult = new StringBuilder();
+				var subResult = new StringBuilder();
 				for (Entry> entry : channelsByComponent.asMap().entrySet()) {
 					if (subResult.length() > 0) {
 						subResult.append("; ");
@@ -213,9 +212,8 @@ public static String activeStateChannelsToString(
 							.map(channel -> {
 								if (!channel.getText().isEmpty()) {
 									return channel.getText();
-								} else {
-									return channel.getId();
 								}
+								return channel.getId();
 							}) //
 							.collect(Collectors.joining(", ")));
 				}
@@ -227,7 +225,7 @@ public static String activeStateChannelsToString(
 
 	/**
 	 * Gets information about the given user {@link User}.
-	 * 
+	 *
 	 * @param user {@link User} to read information
 	 * @return {@link Map} about the user
 	 * @throws OpenemsNamedException on error
@@ -236,7 +234,7 @@ public static String activeStateChannelsToString(
 
 	/**
 	 * Update the given user {@link User} with new information {@link JsonObject}.
-	 * 
+	 *
 	 * @param user       {@link User} to update
 	 * @param jsonObject {@link JsonObject} information about the user
 	 * @throws OpenemsNamedException on error
@@ -245,7 +243,7 @@ public static String activeStateChannelsToString(
 
 	/**
 	 * Returns the Setup Protocol PDF for the given id.
-	 * 
+	 *
 	 * @param user            {@link User} the current user
 	 * @param setupProtocolId the setup protocol id to search
 	 * @return the Setup Protocol PDF as a byte array
@@ -255,7 +253,7 @@ public static String activeStateChannelsToString(
 
 	/**
 	 * Submit the installation assistant protocol.
-	 * 
+	 *
 	 * @param user       {@link User} the current user
 	 * @param jsonObject {@link JsonObject} the setup protocol
 	 * @return id of created setup protocol
@@ -265,7 +263,7 @@ public static String activeStateChannelsToString(
 
 	/**
 	 * Register a user.
-	 * 
+	 *
 	 * @param jsonObject {@link JsonObject} that represents an user
 	 * @throws OpenemsNamedException on error
 	 */
@@ -273,7 +271,7 @@ public static String activeStateChannelsToString(
 
 	/**
 	 * Update language from given user.
-	 * 
+	 *
 	 * @param user     {@link User} the current user
 	 * @param language to set language
 	 * @throws OpenemsNamedException on error
diff --git a/io.openems.backend.common/src/io/openems/backend/common/metadata/User.java b/io.openems.backend.common/src/io/openems/backend/common/metadata/User.java
index 9fbee5b8d8d..6b15d66f796 100644
--- a/io.openems.backend.common/src/io/openems/backend/common/metadata/User.java
+++ b/io.openems.backend.common/src/io/openems/backend/common/metadata/User.java
@@ -4,7 +4,6 @@
 import java.util.List;
 import java.util.Map.Entry;
 import java.util.NavigableMap;
-import java.util.Optional;
 
 import io.openems.common.exceptions.OpenemsError;
 import io.openems.common.exceptions.OpenemsError.OpenemsNamedException;
@@ -33,7 +32,7 @@ public User(String id, String name, String token, Role globalRole, NavigableMap<
 
 	/**
 	 * Gets the login token.
-	 * 
+	 *
 	 * @return the token
 	 */
 	public String getToken() {
@@ -42,23 +41,23 @@ public String getToken() {
 
 	/**
 	 * Gets the user language.
-	 * 
+	 *
 	 * @return the language
 	 */
 	public String getLanguage() {
-		return language;
+		return this.language;
 	}
 
 	/**
 	 * Gets the information whether the Users Role for the given Edge is equal or
 	 * more privileged than the given Role.
-	 * 
+	 *
 	 * @param edgeId the Edge-Id
 	 * @param role   the compared Role
 	 * @return true if the Users Role privileges are equal or higher
 	 */
 	public boolean roleIsAtLeast(String edgeId, Role role) {
-		Optional thisRoleOpt = this.getRole(edgeId);
+		var thisRoleOpt = this.getRole(edgeId);
 		if (!thisRoleOpt.isPresent()) {
 			return false;
 		}
@@ -68,7 +67,7 @@ public boolean roleIsAtLeast(String edgeId, Role role) {
 	/**
 	 * Throws an exception if the current Role is equal or more privileged than the
 	 * given Role.
-	 * 
+	 *
 	 * @param resource a resource identifier; used for the exception
 	 * @param edgeId   the Edge-ID
 	 * @param role     the compared Role
@@ -76,11 +75,11 @@ public boolean roleIsAtLeast(String edgeId, Role role) {
 	 * @throws OpenemsNamedException if the current Role privileges are less
 	 */
 	public Role assertEdgeRoleIsAtLeast(String resource, String edgeId, Role role) throws OpenemsNamedException {
-		Optional thisRoleOpt = this.getRole(edgeId);
+		var thisRoleOpt = this.getRole(edgeId);
 		if (!thisRoleOpt.isPresent()) {
 			throw OpenemsError.COMMON_ROLE_UNDEFINED.exception(this.getId());
 		}
-		Role thisRole = thisRoleOpt.get();
+		var thisRole = thisRoleOpt.get();
 		if (!thisRole.isAtLeast(role)) {
 			throw OpenemsError.COMMON_ROLE_ACCESS_DENIED.exception(resource, role.toString());
 		}
@@ -89,7 +88,7 @@ public Role assertEdgeRoleIsAtLeast(String resource, String edgeId, Role role) t
 
 	/**
 	 * Gets the Metadata information of the accessible Edges.
-	 * 
+	 *
 	 * @param user            the {@link User}
 	 * @param metadataService a {@link Metadata} provider
 	 * @return a list of {@link EdgeMetadata}
@@ -97,18 +96,18 @@ public Role assertEdgeRoleIsAtLeast(String resource, String edgeId, Role role) t
 	public static List generateEdgeMetadatas(User user, Metadata metadataService) {
 		List metadatas = new ArrayList<>();
 		for (Entry edgeRole : user.getEdgeRoles().entrySet()) {
-			String edgeId = edgeRole.getKey();
-			Role role = edgeRole.getValue();
-			Optional edgeOpt = metadataService.getEdge(edgeId);
+			var edgeId = edgeRole.getKey();
+			var role = edgeRole.getValue();
+			var edgeOpt = metadataService.getEdge(edgeId);
 			if (edgeOpt.isPresent()) {
-				Edge e = edgeOpt.get();
+				var edge = edgeOpt.get();
 				metadatas.add(new EdgeMetadata(//
-						e.getId(), // Edge-ID
-						e.getComment(), // Comment
-						e.getProducttype(), // Product-Type
-						e.getVersion(), // Version
+						edge.getId(), // Edge-ID
+						edge.getComment(), // Comment
+						edge.getProducttype(), // Product-Type
+						edge.getVersion(), // Version
 						role, // Role
-						e.isOnline() // Online-State
+						edge.isOnline() // Online-State
 				));
 			}
 		}
diff --git a/io.openems.backend.common/src/io/openems/backend/common/timedata/EdgeCache.java b/io.openems.backend.common/src/io/openems/backend/common/timedata/EdgeCache.java
index 1507dc88d0f..b2b3d7c6f59 100644
--- a/io.openems.backend.common/src/io/openems/backend/common/timedata/EdgeCache.java
+++ b/io.openems.backend.common/src/io/openems/backend/common/timedata/EdgeCache.java
@@ -21,19 +21,31 @@ public class EdgeCache {
 	/**
 	 * The Timestamp of the data in the Cache.
 	 */
-	private long cacheTimestamp = 0l;
+	private long cacheTimestamp = 0L;
 
 	/**
 	 * The Timestamp when the Cache was last applied to the incoming data.
 	 */
-	private long lastAppliedTimestamp = 0l;
+	private long lastAppliedTimestamp = 0L;
 
 	private final HashMap cacheData = new HashMap<>();
 
-	public synchronized final Optional getChannelValue(ChannelAddress address) {
+	/**
+	 * Gets the channel value from cache.
+	 * 
+	 * @param address the {@link ChannelAddress} of the channel
+	 * @return the value; empty if it is not in cache
+	 */
+	public final synchronized Optional getChannelValue(ChannelAddress address) {
 		return Optional.ofNullable(this.cacheData.get(address));
 	}
 
+	/**
+	 * Updates the 'incoming data' with the data from the cache.
+	 * 
+	 * @param edgeId        the Edge-ID
+	 * @param incomingDatas the incoming data
+	 */
 	public synchronized void complementDataFromCache(String edgeId,
 			SortedMap> incomingDatas) {
 		for (Entry> entry : incomingDatas.entrySet()) {
@@ -52,7 +64,7 @@ public synchronized void complementDataFromCache(String edgeId,
 					if (this.cacheTimestamp != 0L) {
 						this.log.info("Edge [" + edgeId + "]: invalidate cache. Incoming ["
 								+ Instant.ofEpochMilli(incomingTimestamp) + "]. Cache ["
-								+ Instant.ofEpochMilli(cacheTimestamp) + "]");
+								+ Instant.ofEpochMilli(this.cacheTimestamp) + "]");
 					}
 					// Clear Cache
 					this.cacheData.clear();
@@ -66,7 +78,7 @@ public synchronized void complementDataFromCache(String edgeId,
 					// cache is valid (not elder than 5 minutes)
 					this.lastAppliedTimestamp = incomingTimestamp;
 					for (Entry cacheEntry : this.cacheData.entrySet()) {
-						ChannelAddress channel = cacheEntry.getKey();
+						var channel = cacheEntry.getKey();
 						// check if there is a current value for this timestamp + channel
 						if (!incomingData.containsKey(channel)) {
 							// if not -> add cache data to write data
diff --git a/io.openems.backend.common/src/io/openems/backend/common/timedata/Timedata.java b/io.openems.backend.common/src/io/openems/backend/common/timedata/Timedata.java
index 201bb8ec071..dc27fa5d687 100644
--- a/io.openems.backend.common/src/io/openems/backend/common/timedata/Timedata.java
+++ b/io.openems.backend.common/src/io/openems/backend/common/timedata/Timedata.java
@@ -16,20 +16,20 @@ public interface Timedata extends CommonTimedataService {
 
 	/**
 	 * Sends the data points to the Timedata service.
-	 * 
+	 *
 	 * @param edgeId The unique Edge-ID
 	 * @param data   Table of timestamp (epoch in milliseconds), Channel-Address and
 	 *               the Channel value as JsonElement. Sorted by timestamp.
-	 * @throws OpenemsException
+	 * @throws OpenemsException on error
 	 */
 	public void write(String edgeId, TreeBasedTable data) throws OpenemsException;
 
 	/**
 	 * Gets the latest value for the given ChannelAddress.
-	 * 
+	 *
 	 * @param edgeId         The unique Edge-ID
 	 * @param channelAddress The Channel-Address
-	 * @return
+	 * @return the value
 	 */
 	public Optional getChannelValue(String edgeId, ChannelAddress channelAddress);
 
diff --git a/io.openems.backend.common/src/io/openems/backend/common/uiwebsocket/UiWebsocket.java b/io.openems.backend.common/src/io/openems/backend/common/uiwebsocket/UiWebsocket.java
index fbd75ca8318..8e63b295948 100644
--- a/io.openems.backend.common/src/io/openems/backend/common/uiwebsocket/UiWebsocket.java
+++ b/io.openems.backend.common/src/io/openems/backend/common/uiwebsocket/UiWebsocket.java
@@ -15,7 +15,7 @@ public interface UiWebsocket {
 	/**
 	 * Send a JSON-RPC Request to a UI session via WebSocket and expect a JSON-RPC
 	 * Response.
-	 * 
+	 *
 	 * @param token   the UI token
 	 * @param request the JsonrpcRequest
 	 * @return the JSON-RPC Success Response Future
@@ -26,7 +26,7 @@ public CompletableFuture send(String token, JsonrpcReque
 
 	/**
 	 * Send a JSON-RPC Notification to a UI session.
-	 * 
+	 *
 	 * @param token        the UI token
 	 * @param notification the JsonrpcNotification
 	 * @throws OpenemsNamedException on error
@@ -36,7 +36,7 @@ public CompletableFuture send(String token, JsonrpcReque
 	/**
 	 * Send a JSON-RPC Notification broadcast to all UI sessions with a given
 	 * Edge-ID.
-	 * 
+	 *
 	 * @param edgeId       the Edge-ID
 	 * @param notification the JsonrpcNotification
 	 * @throws OpenemsNamedException on error
diff --git a/io.openems.backend.core/src/io/openems/backend/core/jsonrpcrequesthandler/EdgeRpcRequestHandler.java b/io.openems.backend.core/src/io/openems/backend/core/jsonrpcrequesthandler/EdgeRpcRequestHandler.java
index 3e70153dbaf..5e17d13410e 100644
--- a/io.openems.backend.core/src/io/openems/backend/core/jsonrpcrequesthandler/EdgeRpcRequestHandler.java
+++ b/io.openems.backend.core/src/io/openems/backend/core/jsonrpcrequesthandler/EdgeRpcRequestHandler.java
@@ -11,7 +11,6 @@
 import io.openems.backend.common.metadata.User;
 import io.openems.common.exceptions.OpenemsError;
 import io.openems.common.exceptions.OpenemsError.OpenemsNamedException;
-import io.openems.common.jsonrpc.base.JsonrpcRequest;
 import io.openems.common.jsonrpc.base.JsonrpcResponseSuccess;
 import io.openems.common.jsonrpc.request.ComponentJsonApiRequest;
 import io.openems.common.jsonrpc.request.CreateComponentConfigRequest;
@@ -31,7 +30,6 @@
 import io.openems.common.jsonrpc.response.QueryHistoricTimeseriesEnergyResponse;
 import io.openems.common.session.Role;
 import io.openems.common.types.ChannelAddress;
-import io.openems.common.types.EdgeConfig;
 
 public class EdgeRpcRequestHandler {
 
@@ -43,7 +41,7 @@ protected EdgeRpcRequestHandler(JsonRpcRequestHandlerImpl parent) {
 
 	/**
 	 * Handles an {@link EdgeRpcRequest}.
-	 * 
+	 *
 	 * @param user           the {@link User}
 	 * @param edgeRpcRequest the {@link EdgeRpcRequest}
 	 * @param messageId      the JSON-RPC Message-ID
@@ -52,8 +50,8 @@ protected EdgeRpcRequestHandler(JsonRpcRequestHandlerImpl parent) {
 	 */
 	protected CompletableFuture handleRequest(User user, UUID messageId, EdgeRpcRequest edgeRpcRequest)
 			throws OpenemsNamedException {
-		String edgeId = edgeRpcRequest.getEdgeId();
-		JsonrpcRequest request = edgeRpcRequest.getPayload();
+		var edgeId = edgeRpcRequest.getEdgeId();
+		var request = edgeRpcRequest.getPayload();
 		user.assertEdgeRoleIsAtLeast(EdgeRpcRequest.METHOD, edgeRpcRequest.getEdgeId(), Role.GUEST);
 
 		CompletableFuture resultFuture;
@@ -111,7 +109,7 @@ protected CompletableFuture handleRequest(User user, UUID messa
 		}
 
 		// Wrap reply in EdgeRpcResponse
-		CompletableFuture result = new CompletableFuture();
+		var result = new CompletableFuture();
 		resultFuture.whenComplete((r, ex) -> {
 			if (ex != null) {
 				result.completeExceptionally(ex);
@@ -127,7 +125,7 @@ protected CompletableFuture handleRequest(User user, UUID messa
 
 	/**
 	 * Handles a {@link QueryHistoricTimeseriesDataRequest}.
-	 * 
+	 *
 	 * @param edgeId  the Edge-ID
 	 * @param user    the {@link User} - no specific level required
 	 * @param request the {@link QueryHistoricTimeseriesDataRequest}
@@ -146,7 +144,7 @@ private CompletableFuture handleQueryHistoricDataRequest
 
 	/**
 	 * Handles a {@link QueryHistoricTimeseriesEnergyRequest}.
-	 * 
+	 *
 	 * @param edgeId  the Edge-ID
 	 * @param user    the {@link User} - no specific level required
 	 * @param request the {@link QueryHistoricTimeseriesEnergyRequest}
@@ -164,7 +162,7 @@ private CompletableFuture handleQueryHistoricEnergyReque
 
 	/**
 	 * Handles a {@link QueryHistoricTimeseriesEnergyPerPeriodRequest}.
-	 * 
+	 *
 	 * @param edgeId  the Edge-ID
 	 * @param user    the {@link User} - no specific level required
 	 * @param request the {@link QueryHistoricTimeseriesEnergyPerPeriodRequest}
@@ -185,7 +183,7 @@ private CompletableFuture handleQueryHistoricEnergyPerPe
 
 	/**
 	 * Handles a {@link QueryHistoricTimeseriesExportXlxsRequest}.
-	 * 
+	 *
 	 * @param edgeId  the Edge-ID
 	 * @param user    the {@link User}
 	 * @param request the {@link QueryHistoricTimeseriesExportXlxsRequest}
@@ -200,7 +198,7 @@ private CompletableFuture handleQueryHistoricTimeseriesE
 
 	/**
 	 * Handles a {@link GetEdgeConfigRequest}.
-	 * 
+	 *
 	 * @param edgeId  the Edge-ID
 	 * @param user    the {@link User} - no specific level required
 	 * @param request the {@link GetEdgeConfigRequest}
@@ -209,7 +207,7 @@ private CompletableFuture handleQueryHistoricTimeseriesE
 	 */
 	private CompletableFuture handleGetEdgeConfigRequest(String edgeId, User user,
 			GetEdgeConfigRequest request) throws OpenemsNamedException {
-		EdgeConfig config = this.parent.metadata.getEdgeOrError(edgeId).getConfig();
+		var config = this.parent.metadata.getEdgeOrError(edgeId).getConfig();
 
 		// JSON-RPC response
 		return CompletableFuture.completedFuture(new GetEdgeConfigResponse(request.getId(), config));
@@ -217,7 +215,7 @@ private CompletableFuture handleGetEdgeConfigRequest(Str
 
 	/**
 	 * Handles a {@link CreateComponentConfigRequest}.
-	 * 
+	 *
 	 * @param edgeId  the Edge-ID
 	 * @param user    the {@link User} - Installer-level required
 	 * @param request the {@link CreateComponentConfigRequest}
@@ -233,7 +231,7 @@ private CompletableFuture handleCreateComponentConfigReq
 
 	/**
 	 * Handles a {@link UpdateComponentConfigRequest}.
-	 * 
+	 *
 	 * @param edgeId  the Edge-ID
 	 * @param user    the {@link User} - Installer-level required
 	 * @param request the {@link UpdateComponentConfigRequest}
@@ -249,7 +247,7 @@ private CompletableFuture handleUpdateComponentConfigReq
 
 	/**
 	 * Handles a {@link DeleteComponentConfigRequest}.
-	 * 
+	 *
 	 * @param edgeId  the Edge-ID
 	 * @param user    the {@link User} - Installer-level required
 	 * @param request the {@link DeleteComponentConfigRequest}
@@ -265,7 +263,7 @@ private CompletableFuture handleDeleteComponentConfigReq
 
 	/**
 	 * Handles a {@link SetChannelValueRequest}.
-	 * 
+	 *
 	 * @param edgeId  the Edge-ID
 	 * @param user    the {@link User}
 	 * @param request the {@link SetChannelValueRequest}
@@ -281,7 +279,7 @@ private CompletableFuture handleSetChannelValueRequest(S
 
 	/**
 	 * Handles a {@link UpdateComponentConfigRequest}.
-	 * 
+	 *
 	 * @param edgeId                  the Edge-ID
 	 * @param user                    the {@link User} - Guest-level required
 	 * @param componentJsonApiRequest the {@link ComponentJsonApiRequest}
diff --git a/io.openems.backend.core/src/io/openems/backend/core/jsonrpcrequesthandler/JsonRpcRequestHandlerImpl.java b/io.openems.backend.core/src/io/openems/backend/core/jsonrpcrequesthandler/JsonRpcRequestHandlerImpl.java
index f8d30a68b03..24da43e5438 100644
--- a/io.openems.backend.core/src/io/openems/backend/core/jsonrpcrequesthandler/JsonRpcRequestHandlerImpl.java
+++ b/io.openems.backend.core/src/io/openems/backend/core/jsonrpcrequesthandler/JsonRpcRequestHandlerImpl.java
@@ -3,7 +3,6 @@
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Map.Entry;
-import java.util.Optional;
 import java.util.UUID;
 import java.util.concurrent.CompletableFuture;
 
@@ -14,7 +13,6 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import com.google.gson.JsonElement;
 import com.google.gson.JsonNull;
 
 import io.openems.backend.common.component.AbstractOpenemsBackendComponent;
@@ -25,7 +23,6 @@
 import io.openems.backend.common.jsonrpc.response.GetEdgesChannelsValuesResponse;
 import io.openems.backend.common.jsonrpc.response.GetEdgesStatusResponse;
 import io.openems.backend.common.jsonrpc.response.GetEdgesStatusResponse.EdgeInfo;
-import io.openems.backend.common.metadata.Edge;
 import io.openems.backend.common.metadata.Metadata;
 import io.openems.backend.common.metadata.User;
 import io.openems.backend.common.timedata.Timedata;
@@ -66,13 +63,14 @@ public JsonRpcRequestHandlerImpl() {
 
 	/**
 	 * Handles a JSON-RPC Request.
-	 * 
+	 *
 	 * @param context the Logger context, i.e. the name of the parent source
 	 * @param user    the {@link User}
 	 * @param request the JsonrpcRequest
 	 * @return the JSON-RPC Success Response Future
 	 * @throws OpenemsNamedException on error
 	 */
+	@Override
 	public CompletableFuture handleRequest(String context, User user,
 			JsonrpcRequest request) throws OpenemsNamedException {
 		switch (request.getMethod()) {
@@ -99,7 +97,7 @@ public CompletableFuture handleRequest(String
 
 	/**
 	 * Handles a {@link GetEdgesStatusRequest}.
-	 * 
+	 *
 	 * @param user      the {@link User}
 	 * @param messageId the JSON-RPC Message-ID
 	 * @param request   the {@link GetEdgesStatusRequest}
@@ -110,17 +108,17 @@ private CompletableFuture handleGetStatusOfEdgesRequest(
 			GetEdgesStatusRequest request) throws OpenemsNamedException {
 		Map result = new HashMap<>();
 		for (Entry entry : user.getEdgeRoles().entrySet()) {
-			String edgeId = entry.getKey();
+			var edgeId = entry.getKey();
 
 			// assure read permissions of this User for this Edge.
 			if (!user.roleIsAtLeast(edgeId, Role.GUEST)) {
 				continue;
 			}
 
-			Optional edgeOpt = this.metadata.getEdge(edgeId);
+			var edgeOpt = this.metadata.getEdge(edgeId);
 			if (edgeOpt.isPresent()) {
-				Edge edge = edgeOpt.get();
-				EdgeInfo info = new EdgeInfo(edge.isOnline());
+				var edge = edgeOpt.get();
+				var info = new EdgeInfo(edge.isOnline());
 				result.put(edge.getId(), info);
 			}
 		}
@@ -129,7 +127,7 @@ private CompletableFuture handleGetStatusOfEdgesRequest(
 
 	/**
 	 * Handles a {@link GetEdgesChannelsValuesRequest}.
-	 * 
+	 *
 	 * @param user      the {@link User}
 	 * @param messageId the JSON-RPC Message-ID
 	 * @param request   the GetChannelsValuesRequest
@@ -138,7 +136,7 @@ private CompletableFuture handleGetStatusOfEdgesRequest(
 	 */
 	private CompletableFuture handleGetChannelsValuesRequest(User user, UUID messageId,
 			GetEdgesChannelsValuesRequest request) throws OpenemsNamedException {
-		GetEdgesChannelsValuesResponse response = new GetEdgesChannelsValuesResponse(messageId);
+		var response = new GetEdgesChannelsValuesResponse(messageId);
 		for (String edgeId : request.getEdgeIds()) {
 			// assure read permissions of this User for this Edge.
 			if (!user.roleIsAtLeast(edgeId, Role.GUEST)) {
@@ -146,7 +144,7 @@ private CompletableFuture handleGetChannelsValue
 			}
 
 			for (ChannelAddress channel : request.getChannels()) {
-				Optional value = this.timeData.getChannelValue(edgeId, channel);
+				var value = this.timeData.getChannelValue(edgeId, channel);
 				response.addValue(edgeId, channel, value.orElse(JsonNull.INSTANCE));
 			}
 		}
@@ -155,7 +153,7 @@ private CompletableFuture handleGetChannelsValue
 
 	/**
 	 * Handles a {@link SetGridConnScheduleRequest}.
-	 * 
+	 *
 	 * @param user                       the {@link User}
 	 * @param messageId                  the JSON-RPC Message-ID
 	 * @param setGridConnScheduleRequest the {@link SetGridConnScheduleRequest}
@@ -164,17 +162,17 @@ private CompletableFuture handleGetChannelsValue
 	 */
 	private CompletableFuture handleSetGridConnScheduleRequest(User user, UUID messageId,
 			SetGridConnScheduleRequest setGridConnScheduleRequest) throws OpenemsNamedException {
-		String edgeId = setGridConnScheduleRequest.getEdgeId();
+		var edgeId = setGridConnScheduleRequest.getEdgeId();
 		user.assertEdgeRoleIsAtLeast(SetGridConnScheduleRequest.METHOD, edgeId, Role.ADMIN);
 
 		// wrap original request inside ComponentJsonApiRequest
-		String componentId = "ctrlBalancingSchedule0"; // TODO find dynamic Component-ID of BalancingScheduleController
-		ComponentJsonApiRequest request = new ComponentJsonApiRequest(componentId, setGridConnScheduleRequest);
+		var componentId = "ctrlBalancingSchedule0"; // TODO find dynamic Component-ID of BalancingScheduleController
+		var request = new ComponentJsonApiRequest(componentId, setGridConnScheduleRequest);
 
-		CompletableFuture resultFuture = this.edgeWebsocket.send(edgeId, user, request);
+		var resultFuture = this.edgeWebsocket.send(edgeId, user, request);
 
 		// Wrap reply in GenericJsonrpcResponseSuccess
-		CompletableFuture result = new CompletableFuture();
+		var result = new CompletableFuture();
 		resultFuture.whenComplete((r, ex) -> {
 			if (ex != null) {
 				result.completeExceptionally(ex);
@@ -190,7 +188,7 @@ private CompletableFuture handleSetGridConnSchedu
 
 	/**
 	 * Log an info message including the Handler name.
-	 * 
+	 *
 	 * @param context the Logger context, i.e. the name of the parent source
 	 * @param message the Info-message
 	 */
@@ -200,7 +198,7 @@ protected void logInfo(String context, String message) {
 
 	/**
 	 * Log a warn message including the Handler name.
-	 * 
+	 *
 	 * @param context the Logger context, i.e. the name of the parent source
 	 * @param message the Warn-message
 	 */
@@ -210,7 +208,7 @@ protected void logWarn(String context, String message) {
 
 	/**
 	 * Log an error message including the Handler name.
-	 * 
+	 *
 	 * @param context the Logger context, i.e. the name of the parent source
 	 * @param message the Error-message
 	 */
diff --git a/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/EdgeWebsocketImpl.java b/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/EdgeWebsocketImpl.java
index 4deb9893861..47cf565ddfc 100644
--- a/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/EdgeWebsocketImpl.java
+++ b/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/EdgeWebsocketImpl.java
@@ -1,6 +1,5 @@
 package io.openems.backend.edgewebsocket;
 
-import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
 
 import org.java_websocket.WebSocket;
@@ -62,24 +61,24 @@ public EdgeWebsocketImpl() {
 	private Config config;
 
 	private final Runnable startServerWhenMetadataIsInitialized = () -> {
-		this.startServer(config.port(), config.poolSize(), config.debugMode());
+		this.startServer(this.config.port(), this.config.poolSize(), this.config.debugMode());
 	};
 
 	@Activate
-	void activate(Config config) {
+	private void activate(Config config) {
 		this.config = config;
 		this.metadata.addOnIsInitializedListener(this.startServerWhenMetadataIsInitialized);
 	}
 
 	@Deactivate
-	void deactivate() {
+	private void deactivate() {
 		this.metadata.removeOnIsInitializedListener(this.startServerWhenMetadataIsInitialized);
 		this.stopServer();
 	}
 
 	/**
 	 * Create and start new server.
-	 * 
+	 *
 	 * @param port      the port
 	 * @param poolSize  number of threads dedicated to handle the tasks
 	 * @param debugMode activate a regular debug log about the state of the tasks
@@ -100,7 +99,7 @@ private synchronized void stopServer() {
 
 	/**
 	 * Gets whether the Websocket for this Edge is connected.
-	 * 
+	 *
 	 * @param edgeId the Edge-ID
 	 * @return true if it is online
 	 */
@@ -111,40 +110,39 @@ protected boolean isOnline(String edgeId) {
 	@Override
 	public CompletableFuture send(String edgeId, User user, JsonrpcRequest request)
 			throws OpenemsNamedException {
-		WebSocket ws = this.getWebSocketForEdgeId(edgeId);
-		if (ws != null) {
-			WsData wsData = ws.getAttachment();
-			// Wrap Request in AuthenticatedRpc
-			AuthenticatedRpcRequest authenticatedRpc = new AuthenticatedRpcRequest(edgeId, user, request);
-			CompletableFuture responseFuture = wsData.send(authenticatedRpc);
-
-			// Unwrap Response
-			CompletableFuture result = new CompletableFuture();
-			responseFuture.whenComplete((r, ex) -> {
-				if (ex != null) {
-					result.completeExceptionally(ex);
-				} else if (r != null) {
-					try {
-						AuthenticatedRpcResponse response = AuthenticatedRpcResponse.from(r);
-						result.complete(response.getPayload());
-					} catch (OpenemsNamedException e) {
-						this.logError(this.log, e.getMessage());
-						result.completeExceptionally(e);
-					}
-				} else {
-					result.completeExceptionally(
-							new OpenemsNamedException(OpenemsError.JSONRPC_UNHANDLED_METHOD, request.getMethod()));
-				}
-			});
-			return result;
-		} else {
+		var ws = this.getWebSocketForEdgeId(edgeId);
+		if (ws == null) {
 			throw OpenemsError.BACKEND_EDGE_NOT_CONNECTED.exception(edgeId);
 		}
+		WsData wsData = ws.getAttachment();
+		// Wrap Request in AuthenticatedRpc
+		var authenticatedRpc = new AuthenticatedRpcRequest<>(edgeId, user, request);
+		var responseFuture = wsData.send(authenticatedRpc);
+
+		// Unwrap Response
+		var result = new CompletableFuture();
+		responseFuture.whenComplete((r, ex) -> {
+			if (ex != null) {
+				result.completeExceptionally(ex);
+			} else if (r != null) {
+				try {
+					var response = AuthenticatedRpcResponse.from(r);
+					result.complete(response.getPayload());
+				} catch (OpenemsNamedException e) {
+					this.logError(this.log, e.getMessage());
+					result.completeExceptionally(e);
+				}
+			} else {
+				result.completeExceptionally(
+						new OpenemsNamedException(OpenemsError.JSONRPC_UNHANDLED_METHOD, request.getMethod()));
+			}
+		});
+		return result;
 	}
 
 	@Override
 	public void send(String edgeId, JsonrpcNotification notification) throws OpenemsException {
-		WebSocket ws = this.getWebSocketForEdgeId(edgeId);
+		var ws = this.getWebSocketForEdgeId(edgeId);
 		if (ws != null) {
 			WsData wsData = ws.getAttachment();
 			wsData.send(notification);
@@ -154,15 +152,15 @@ public void send(String edgeId, JsonrpcNotification notification) throws Openems
 	/**
 	 * Gets the WebSocket connection for an Edge-ID. If more than one connection
 	 * exists, the first one is returned. Returns null if none is found.
-	 * 
+	 *
 	 * @param edgeId the Edge-ID
 	 * @return the WebSocket connection
 	 */
 	private final WebSocket getWebSocketForEdgeId(String edgeId) {
 		for (WebSocket ws : this.server.getConnections()) {
 			WsData wsData = ws.getAttachment();
-			Optional wsEdgeId = wsData.getEdgeId();
-			if (wsEdgeId.isPresent() && wsEdgeId.get().equals(edgeId)) {
+			var wsEdgeIdOpt = wsData.getEdgeId();
+			if (wsEdgeIdOpt.isPresent() && wsEdgeIdOpt.get().equals(edgeId)) {
 				return ws;
 			}
 		}
@@ -188,7 +186,7 @@ public CompletableFuture handleSubscribeSystemLogRequest
 	/**
 	 * Handles a {@link SystemLogNotification}, i.e. the replies to
 	 * {@link SubscribeSystemLogRequest}.
-	 * 
+	 *
 	 * @param edgeId       the Edge-ID
 	 * @param notification the SystemLogNotification
 	 */
diff --git a/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/OnClose.java b/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/OnClose.java
index c181a15bb58..450af63c330 100644
--- a/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/OnClose.java
+++ b/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/OnClose.java
@@ -1,13 +1,10 @@
 package io.openems.backend.edgewebsocket;
 
-import java.util.Optional;
-
 import org.java_websocket.WebSocket;
 import org.java_websocket.framing.CloseFrame;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import io.openems.backend.common.metadata.Edge;
 import io.openems.common.exceptions.OpenemsException;
 
 public class OnClose implements io.openems.common.websocket.OnClose {
@@ -23,15 +20,15 @@ public OnClose(EdgeWebsocketImpl parent) {
 	public void run(WebSocket ws, int code, String reason, boolean remote) throws OpenemsException {
 		// get edgeId from websocket
 		WsData wsData = ws.getAttachment();
-		Optional edgeIdOpt = wsData.getEdgeId();
+		var edgeIdOpt = wsData.getEdgeId();
 		String edgeId;
 		if (edgeIdOpt.isPresent()) {
 			edgeId = edgeIdOpt.get();
-			Optional edgeOpt = this.parent.metadata.getEdge(edgeId);
+			var edgeOpt = this.parent.metadata.getEdge(edgeId);
 			// if there is no other websocket connection for this edgeId -> announce Edge as
 			// offline
 			if (edgeOpt.isPresent()) {
-				boolean isOnline = this.parent.isOnline(edgeId);
+				var isOnline = this.parent.isOnline(edgeId);
 				edgeOpt.get().setOnline(isOnline);
 			}
 
diff --git a/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/OnError.java b/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/OnError.java
index 94dbde7cb91..16fad99467b 100644
--- a/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/OnError.java
+++ b/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/OnError.java
@@ -1,7 +1,5 @@
 package io.openems.backend.edgewebsocket;
 
-import java.util.Optional;
-
 import org.java_websocket.WebSocket;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -16,13 +14,13 @@ public class OnError implements io.openems.common.websocket.OnError {
 	public OnError(EdgeWebsocketImpl parent) {
 		this.parent = parent;
 	}
-	
+
 	@Override
 	public void run(WebSocket ws, Exception ex) throws OpenemsException {
 		WsData wsData = ws.getAttachment();
-		Optional edgeId = wsData.getEdgeId();
-		this.parent.logWarn(this.log, "Edge [" + edgeId.orElse("UNKNOWN") + "] websocket error. " + ex.getClass().getSimpleName() + ": "
-				+ ex.getMessage());
+		var edgeIdOpt = wsData.getEdgeId();
+		this.parent.logWarn(this.log, "Edge [" + edgeIdOpt.orElse("UNKNOWN") + "] websocket error. "
+				+ ex.getClass().getSimpleName() + ": " + ex.getMessage());
 		ex.printStackTrace();
 	}
 
diff --git a/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/OnNotification.java b/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/OnNotification.java
index eaa7dcb7a1c..8029c340b88 100644
--- a/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/OnNotification.java
+++ b/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/OnNotification.java
@@ -1,7 +1,6 @@
 package io.openems.backend.edgewebsocket;
 
 import java.util.Map.Entry;
-import java.util.Optional;
 import java.util.concurrent.TimeUnit;
 
 import org.java_websocket.WebSocket;
@@ -9,9 +8,7 @@
 import org.slf4j.LoggerFactory;
 
 import com.google.gson.JsonElement;
-import com.google.gson.JsonObject;
 
-import io.openems.backend.common.metadata.Edge;
 import io.openems.common.channel.Level;
 import io.openems.common.exceptions.OpenemsError.OpenemsNamedException;
 import io.openems.common.exceptions.OpenemsException;
@@ -44,9 +41,9 @@ public void run(WebSocket ws, JsonrpcNotification notification) throws OpenemsNa
 		}
 
 		// announce incoming message for this Edge
-		Optional edge = wsData.getEdge(this.parent.metadata);
-		if (edge.isPresent()) {
-			edge.get().setLastMessageTimestamp();
+		var edgeOpt = wsData.getEdge(this.parent.metadata);
+		if (edgeOpt.isPresent()) {
+			edgeOpt.get().setLastMessageTimestamp();
 		}
 
 		// Handle notification
@@ -69,16 +66,16 @@ public void run(WebSocket ws, JsonrpcNotification notification) throws OpenemsNa
 
 	/**
 	 * Handles EdgeConfigNotification.
-	 * 
+	 *
 	 * @param message the EdgeConfigNotification
 	 * @param wsData  the WebSocket attachment
 	 * @throws OpenemsException on error
 	 */
 	private void handleEdgeConfigNotification(EdgeConfigNotification message, WsData wsData) throws OpenemsException {
-		String edgeId = wsData.assertEdgeId(message);
+		var edgeId = wsData.assertEdgeId(message);
 
 		// save config in metadata
-		Edge edge = this.parent.metadata.getEdgeOrError(edgeId);
+		var edge = this.parent.metadata.getEdgeOrError(edgeId);
 		edge.setConfig(message.getConfig());
 
 		// forward
@@ -94,14 +91,14 @@ private void handleEdgeConfigNotification(EdgeConfigNotification message, WsData
 
 	/**
 	 * Handles TimestampedDataNotification.
-	 * 
+	 *
 	 * @param message the TimestampedDataNotification
 	 * @param wsData  the WebSocket attachment
 	 * @throws OpenemsNamedException on error
 	 */
 	private void handleTimestampedDataNotification(TimestampedDataNotification message, WsData wsData)
 			throws OpenemsNamedException {
-		String edgeId = wsData.assertEdgeId(message);
+		var edgeId = wsData.assertEdgeId(message);
 
 		try {
 			this.parent.timedata.write(edgeId, message.getData());
@@ -110,9 +107,9 @@ private void handleTimestampedDataNotification(TimestampedDataNotification messa
 		}
 
 		// Read some specific channels
-		Edge edge = this.parent.metadata.getEdgeOrError(edgeId);
+		var edge = this.parent.metadata.getEdgeOrError(edgeId);
 		for (Entry entry : message.getParams().entrySet()) {
-			JsonObject data = JsonUtils.getAsJsonObject(entry.getValue());
+			var data = JsonUtils.getAsJsonObject(entry.getValue());
 			// set Edge last update timestamp only for those channels
 			for (String channel : data.keySet()) {
 				if (channel.endsWith("ActivePower")
@@ -129,7 +126,7 @@ private void handleTimestampedDataNotification(TimestampedDataNotification messa
 			}
 
 			if (data.has("_meta/Version") && data.get("_meta/Version").isJsonPrimitive()) {
-				String version = JsonUtils.getAsPrimitive(data, "_meta/Version").getAsString();
+				var version = JsonUtils.getAsPrimitive(data, "_meta/Version").getAsString();
 				edge.setVersion(SemanticVersion.fromString(version));
 			}
 
@@ -138,14 +135,14 @@ private void handleTimestampedDataNotification(TimestampedDataNotification messa
 
 	/**
 	 * Handles SystemLogNotification.
-	 * 
+	 *
 	 * @param message the SystemLogNotification
 	 * @param wsData  the WebSocket attachment
 	 * @throws OpenemsNamedException on error
 	 */
 	private void handleSystemLogNotification(SystemLogNotification message, WsData wsData)
 			throws OpenemsNamedException {
-		String edgeId = wsData.assertEdgeId(message);
+		var edgeId = wsData.assertEdgeId(message);
 		this.parent.handleSystemLogNotification(edgeId, message);
 	}
 }
diff --git a/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/OnOpen.java b/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/OnOpen.java
index 4fc2050a117..0d2b120b0bd 100644
--- a/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/OnOpen.java
+++ b/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/OnOpen.java
@@ -1,7 +1,5 @@
 package io.openems.backend.edgewebsocket;
 
-import java.util.Optional;
-
 import org.java_websocket.WebSocket;
 import org.java_websocket.framing.CloseFrame;
 import org.slf4j.Logger;
@@ -9,7 +7,6 @@
 
 import com.google.gson.JsonObject;
 
-import io.openems.backend.common.metadata.Edge;
 import io.openems.common.exceptions.OpenemsException;
 import io.openems.common.utils.JsonUtils;
 
@@ -30,7 +27,7 @@ public void run(WebSocket ws, JsonObject handshake) {
 		String apikey = "";
 		try {
 			// get apikey from handshake
-			Optional apikeyOpt = JsonUtils.getAsOptionalString(handshake, "apikey");
+			var apikeyOpt = JsonUtils.getAsOptionalString(handshake, "apikey");
 			if (!apikeyOpt.isPresent()) {
 				throw new OpenemsException("Apikey is missing in handshake");
 			}
@@ -38,19 +35,19 @@ public void run(WebSocket ws, JsonObject handshake) {
 			wsData.setApikey(apikey);
 
 			// get edgeId for apikey
-			Optional edgeIdOpt = this.parent.metadata.getEdgeIdForApikey(apikey);
+			var edgeIdOpt = this.parent.metadata.getEdgeIdForApikey(apikey);
 			if (!edgeIdOpt.isPresent()) {
 				throw new OpenemsException("Unable to authenticate this Apikey.");
 			}
-			String edgeId = edgeIdOpt.get();
+			var edgeId = edgeIdOpt.get();
 			wsData.setEdgeId(edgeId);
 
 			// get metadata for Edge
-			Optional edgeOpt = this.parent.metadata.getEdge(edgeId);
+			var edgeOpt = this.parent.metadata.getEdge(edgeId);
 			if (!edgeOpt.isPresent()) {
 				throw new OpenemsException("Unable to get metadata for Edge [" + edgeId + "]");
 			}
-			Edge edge = edgeOpt.get();
+			var edge = edgeOpt.get();
 
 			// log
 			this.parent.logInfo(this.log, "Edge [" + edge.getId() + "] connected.");
diff --git a/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/OnRequest.java b/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/OnRequest.java
index f6a5251f0e5..100f9362a8f 100644
--- a/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/OnRequest.java
+++ b/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/OnRequest.java
@@ -6,8 +6,8 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import io.openems.common.exceptions.OpenemsError.OpenemsNamedException;
 import io.openems.common.exceptions.OpenemsError;
+import io.openems.common.exceptions.OpenemsError.OpenemsNamedException;
 import io.openems.common.exceptions.OpenemsException;
 import io.openems.common.jsonrpc.base.JsonrpcRequest;
 import io.openems.common.jsonrpc.base.JsonrpcResponseSuccess;
diff --git a/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/SystemLogHandler.java b/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/SystemLogHandler.java
index 5734f1fa1cb..3ccf65b9bfd 100644
--- a/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/SystemLogHandler.java
+++ b/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/SystemLogHandler.java
@@ -1,7 +1,6 @@
 package io.openems.backend.edgewebsocket;
 
 import java.util.Collection;
-import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
 
 import org.slf4j.Logger;
@@ -10,7 +9,6 @@
 import com.google.common.collect.HashMultimap;
 import com.google.common.collect.Multimap;
 
-import io.openems.backend.common.metadata.Edge;
 import io.openems.backend.common.metadata.User;
 import io.openems.common.exceptions.OpenemsError.OpenemsNamedException;
 import io.openems.common.jsonrpc.base.DeprecatedJsonrpcNotification;
@@ -38,7 +36,7 @@ public SystemLogHandler(EdgeWebsocketImpl parent) {
 
 	/**
 	 * Handles a {@link SubscribeSystemLogRequest}.
-	 * 
+	 *
 	 * @param edgeId  the Edge-ID
 	 * @param user    the {@link User}
 	 * @param token   the UI session token
@@ -119,7 +117,7 @@ public void handleSystemLogNotification(String edgeId, User user, SystemLogNotif
 
 	/**
 	 * Unsubscribe from System-Log.
-	 * 
+	 *
 	 * @param edgeId the Edge-ID#
 	 * @param user   the {@link User}; possibly null
 	 * @param token  the UI token
@@ -134,15 +132,14 @@ private void unsubscribe(String edgeId, User user, String token) {
 
 		if (isAnySubscriptionForThisEdgeLeft) {
 			return;
+		}
 
-		} else {
-			// send unsubscribe to Edge
-			try {
-				this.parent.send(edgeId, user, SubscribeSystemLogRequest.unsubscribe());
-			} catch (OpenemsNamedException e) {
-				this.log.error("Unable to Unsubscribe from Edge [" + edgeId + "]");
-				e.printStackTrace();
-			}
+		// send unsubscribe to Edge
+		try {
+			this.parent.send(edgeId, user, SubscribeSystemLogRequest.unsubscribe());
+		} catch (OpenemsNamedException e) {
+			this.log.error("Unable to Unsubscribe from Edge [" + edgeId + "]");
+			e.printStackTrace();
 		}
 	}
 
@@ -150,9 +147,9 @@ private void unsubscribe(String edgeId, User user, String token) {
 	private CompletableFuture sendSubscribe(String edgeId, User user,
 			SubscribeSystemLogRequest request, boolean subscribe) throws OpenemsNamedException {
 		// handling deprecated: remove after full migration
-		Optional edge = this.parent.metadata.getEdge(edgeId);
-		if (edge.isPresent()) {
-			if (!edge.get().getVersion().isAtLeast(new SemanticVersion(2018, 11, 0))) {
+		var edgeOpt = this.parent.metadata.getEdge(edgeId);
+		if (edgeOpt.isPresent()) {
+			if (!edgeOpt.get().getVersion().isAtLeast(new SemanticVersion(2018, 11, 0))) {
 				this.parent.send(edgeId, new DeprecatedJsonrpcNotification(JsonUtils.buildJsonObject() //
 						.add("messageId", JsonUtils.buildJsonObject() //
 								.addProperty("ui", request.getId().toString()) //
diff --git a/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/WebsocketServer.java b/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/WebsocketServer.java
index e1f6e3830a5..67811fc1b52 100644
--- a/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/WebsocketServer.java
+++ b/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/WebsocketServer.java
@@ -14,7 +14,6 @@
 import org.slf4j.LoggerFactory;
 
 import com.google.gson.JsonElement;
-import com.google.gson.JsonObject;
 
 import io.openems.common.exceptions.OpenemsError.OpenemsNamedException;
 import io.openems.common.exceptions.OpenemsException;
@@ -51,10 +50,15 @@ public WebsocketServer(EdgeWebsocketImpl parent, String name, int port, int pool
 
 	@Override
 	protected WsData createWsData() {
-		WsData wsData = new WsData(this);
-		return wsData;
+		return new WsData(this);
 	}
 
+	/**
+	 * Is the given Edge online?.
+	 * 
+	 * @param edgeId the Edge-ID
+	 * @return true if it is online.
+	 */
 	public boolean isOnline(String edgeId) {
 		final Optional edgeIdOpt = Optional.of(edgeId);
 		return this.getConnections().parallelStream().anyMatch(
@@ -73,7 +77,7 @@ protected OnRequest getOnRequest() {
 
 	@Override
 	public OnNotification getOnNotification() {
-		return onNotification;
+		return this.onNotification;
 	}
 
 	@Override
@@ -89,24 +93,24 @@ protected OnClose getOnClose() {
 	@Override
 	protected JsonrpcMessage handleNonJsonrpcMessage(String stringMessage, OpenemsNamedException lastException)
 			throws OpenemsNamedException {
-		JsonObject message = JsonUtils.parseToJsonObject(stringMessage);
+		var message = JsonUtils.parseToJsonObject(stringMessage);
 
 		// config
 		if (message.has("config")) {
-			EdgeConfig config = EdgeConfig.fromJson(JsonUtils.getAsJsonObject(message, "config"));
+			var config = EdgeConfig.fromJson(JsonUtils.getAsJsonObject(message, "config"));
 			return new EdgeConfigNotification(config);
 		}
 
 		// timedata
 		if (message.has("timedata")) {
-			TimestampedDataNotification d = new TimestampedDataNotification();
-			JsonObject timedata = JsonUtils.getAsJsonObject(message, "timedata");
+			var d = new TimestampedDataNotification();
+			var timedata = JsonUtils.getAsJsonObject(message, "timedata");
 			for (Entry entry : timedata.entrySet()) {
-				long timestamp = Long.valueOf(entry.getKey());
-				JsonObject values = JsonUtils.getAsJsonObject(entry.getValue());
+				var timestamp = Long.parseLong(entry.getKey());
+				var values = JsonUtils.getAsJsonObject(entry.getValue());
 				Map data = new HashMap<>();
 				for (Entry value : values.entrySet()) {
-					ChannelAddress address = ChannelAddress.fromString(value.getKey());
+					var address = ChannelAddress.fromString(value.getKey());
 					data.put(address, value.getValue());
 				}
 				d.add(timestamp, data);
@@ -116,7 +120,7 @@ protected JsonrpcMessage handleNonJsonrpcMessage(String stringMessage, OpenemsNa
 
 		// log
 		if (message.has("log")) {
-			JsonObject log = JsonUtils.getAsJsonObject(message, "log");
+			var log = JsonUtils.getAsJsonObject(message, "log");
 			return new SystemLogNotification(new SystemLog(
 					ZonedDateTime.ofInstant(Instant.ofEpochMilli(JsonUtils.getAsLong(log, "time")),
 							ZoneId.systemDefault()), //
@@ -125,7 +129,7 @@ protected JsonrpcMessage handleNonJsonrpcMessage(String stringMessage, OpenemsNa
 					JsonUtils.getAsString(log, "message")));
 		}
 
-		log.info("EdgeWs. handleNonJsonrpcMessage: " + stringMessage);
+		this.log.info("EdgeWs. handleNonJsonrpcMessage: " + stringMessage);
 		throw new OpenemsException("EdgeWs. handleNonJsonrpcMessage", lastException);
 	}
 
diff --git a/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/WsData.java b/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/WsData.java
index f4ccce727c0..7fa48cdbb15 100644
--- a/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/WsData.java
+++ b/io.openems.backend.edgewebsocket/src/io/openems/backend/edgewebsocket/WsData.java
@@ -9,6 +9,7 @@
 
 import io.openems.backend.common.metadata.Edge;
 import io.openems.backend.common.metadata.Metadata;
+import io.openems.common.exceptions.OpenemsError.OpenemsNamedException;
 import io.openems.common.exceptions.OpenemsException;
 import io.openems.common.jsonrpc.base.JsonrpcMessage;
 import io.openems.common.utils.StringUtils;
@@ -16,7 +17,7 @@
 public class WsData extends io.openems.common.websocket.WsData {
 
 	private final WebsocketServer parent;
-	private CompletableFuture isAuthenticated = new CompletableFuture();
+	private final CompletableFuture isAuthenticated = new CompletableFuture<>();
 	private Optional apikey = Optional.empty();
 	private Optional edgeId = Optional.empty();
 
@@ -32,6 +33,14 @@ public CompletableFuture isAuthenticated() {
 		return this.isAuthenticated;
 	}
 
+	/**
+	 * Asserts that the User is authenticated within a timeout.
+	 * 
+	 * @param message a identification message on error
+	 * @param timeout the timeout length
+	 * @param unit    the {@link TimeUnit} of the timeout
+	 * @throws OpenemsNamedException on error
+	 */
 	public void assertAuthenticatedWithTimeout(JsonrpcMessage message, long timeout, TimeUnit unit)
 			throws OpenemsException {
 		try {
@@ -53,7 +62,7 @@ public synchronized void setApikey(String apikey) {
 	}
 
 	public synchronized Optional getApikey() {
-		return apikey;
+		return this.apikey;
 	}
 
 	public synchronized void setEdgeId(String edgeId) {
@@ -61,43 +70,50 @@ public synchronized void setEdgeId(String edgeId) {
 	}
 
 	public synchronized Optional getEdgeId() {
-		return edgeId;
+		return this.edgeId;
 	}
 
 	/**
 	 * Gets the Edge.
-	 * 
+	 *
 	 * @param metadata the Metadata service
 	 * @return the Edge or Optional.Empty if the Edge-ID was not set or it is not
 	 *         available from Metadata service
 	 */
 	public synchronized Optional getEdge(Metadata metadata) {
-		Optional edgeId = this.getEdgeId();
+		var edgeId = this.getEdgeId();
 		if (edgeId.isPresent()) {
-			Optional edge = metadata.getEdge(edgeId.get());
-			return edge;
+			return metadata.getEdge(edgeId.get());
 		}
 		return Optional.empty();
 	}
 
+	/**
+	 * Asserts that the Edge-ID is present.
+	 * 
+	 * @param message a identification message on error
+	 * @return the Edge-ID
+	 * @throws OpenemsException on error
+	 */
 	public String assertEdgeId(JsonrpcMessage message) throws OpenemsException {
 		if (this.edgeId.isPresent()) {
 			return this.edgeId.get();
-		} else {
-			throw new OpenemsException(
-					"EdgeId is not set. Unable to handle " + StringUtils.toShortString(message.toString(), 100));
 		}
+		throw new OpenemsException(
+				"EdgeId is not set. Unable to handle " + StringUtils.toShortString(message.toString(), 100));
 	}
 
 	@Override
 	public String toString() {
-		return "EdgeWebsocket.WsData [apikey=" + apikey.orElse("UNKNOWN") + ", edgeId=" + edgeId.orElse("UNKNOWN")
+		return "EdgeWebsocket.WsData [" //
+				+ "apikey=" + this.apikey.orElse("UNKNOWN") + ", " //
+				+ "edgeId=" + this.edgeId.orElse("UNKNOWN") //
 				+ "]";
 	}
 
 	/**
 	 * Gets an Id of this Edge - either the Edge-ID or the Apikey or "UNKNOWN".
-	 * 
+	 *
 	 * @return the Id
 	 */
 	private String getId() {
diff --git a/io.openems.backend.metadata.dummy/src/io/openems/backend/metadata/dummy/DummyMetadata.java b/io.openems.backend.metadata.dummy/src/io/openems/backend/metadata/dummy/DummyMetadata.java
index 827139ae300..d01679b0c18 100644
--- a/io.openems.backend.metadata.dummy/src/io/openems/backend/metadata/dummy/DummyMetadata.java
+++ b/io.openems.backend.metadata.dummy/src/io/openems/backend/metadata/dummy/DummyMetadata.java
@@ -8,7 +8,6 @@
 import java.util.TreeMap;
 import java.util.UUID;
 import java.util.concurrent.atomic.AtomicInteger;
-import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 import org.osgi.service.component.annotations.Activate;
@@ -61,24 +60,24 @@ public DummyMetadata() {
 	}
 
 	@Activate
-	void activate() {
+	private void activate() {
 		this.logInfo(this.log, "Activate");
 	}
 
 	@Deactivate
-	void deactivate() {
+	private void deactivate() {
 		this.logInfo(this.log, "Deactivate");
 	}
 
 	@Override
 	public User authenticate(String username, String password) throws OpenemsNamedException {
-		String name = "User #" + this.nextUserId.incrementAndGet();
-		String token = UUID.randomUUID().toString();
-		TreeMap roles = new TreeMap<>();
+		var name = "User #" + this.nextUserId.incrementAndGet();
+		var token = UUID.randomUUID().toString();
+		var roles = new TreeMap();
 		for (String edgeId : this.edges.keySet()) {
 			roles.put(edgeId, Role.ADMIN);
 		}
-		User user = new User(username, name, token, Role.ADMIN, roles, this.defaultLanguage.name());
+		var user = new User(username, name, token, Role.ADMIN, roles, this.defaultLanguage.name());
 		this.users.put(user.getId(), user);
 		return user;
 	}
@@ -100,28 +99,27 @@ public void logout(User user) {
 
 	@Override
 	public Optional getEdgeIdForApikey(String apikey) {
-		Optional edgeOpt = this.edges.values().stream() //
+		var edgeOpt = this.edges.values().stream() //
 				.filter(edge -> apikey.equals(edge.getApikey())) //
 				.findFirst();
 		if (edgeOpt.isPresent()) {
 			return Optional.ofNullable(edgeOpt.get().getId());
 		}
 		// not found. Is apikey a valid Edge-ID?
-		Optional idOpt = DummyMetadata.parseNumberFromName(apikey);
+		var idOpt = DummyMetadata.parseNumberFromName(apikey);
 		int id;
 		String edgeId;
 		String setupPassword;
 		if (idOpt.isPresent()) {
 			edgeId = apikey;
 			id = idOpt.get();
-			setupPassword = edgeId;
 		} else {
 			// create new ID
 			id = this.nextEdgeId.incrementAndGet();
 			edgeId = "edge" + id;
-			setupPassword = edgeId;
 		}
-		MyEdge edge = new MyEdge(edgeId, apikey, setupPassword, "OpenEMS Edge #" + id, State.ACTIVE, "", "", Level.OK,
+		setupPassword = edgeId;
+		var edge = new MyEdge(edgeId, apikey, setupPassword, "OpenEMS Edge #" + id, State.ACTIVE, "", "", Level.OK,
 				new EdgeConfig());
 		edge.onSetConfig(config -> {
 			this.logInfo(this.log, "Edge [" + edgeId + "]. Update config: "
@@ -134,11 +132,11 @@ public Optional getEdgeIdForApikey(String apikey) {
 
 	@Override
 	public Optional getEdgeBySetupPassword(String setupPassword) {
-		Optional optEdge = this.edges.values().stream()
-				.filter(edge -> edge.getSetupPassword().equals(setupPassword)).findFirst();
+		var edgeOpt = this.edges.values().stream().filter(edge -> edge.getSetupPassword().equals(setupPassword))
+				.findFirst();
 
-		if (optEdge.isPresent()) {
-			MyEdge edge = optEdge.get();
+		if (edgeOpt.isPresent()) {
+			var edge = edgeOpt.get();
 			return Optional.of(edge);
 		}
 
@@ -163,9 +161,9 @@ public Collection getAllEdges() {
 
 	private static Optional parseNumberFromName(String name) {
 		try {
-			Matcher matcher = NAME_NUMBER_PATTERN.matcher(name);
+			var matcher = DummyMetadata.NAME_NUMBER_PATTERN.matcher(name);
 			if (matcher.find()) {
-				String nameNumberString = matcher.group(1);
+				var nameNumberString = matcher.group(1);
 				return Optional.ofNullable(Integer.parseInt(nameNumberString));
 			}
 		} catch (NullPointerException e) {
diff --git a/io.openems.backend.metadata.file/src/io/openems/backend/metadata/file/FileMetadata.java b/io.openems.backend.metadata.file/src/io/openems/backend/metadata/file/FileMetadata.java
index e6b669615e0..c10a63469d1 100644
--- a/io.openems.backend.metadata.file/src/io/openems/backend/metadata/file/FileMetadata.java
+++ b/io.openems.backend.metadata.file/src/io/openems/backend/metadata/file/FileMetadata.java
@@ -43,18 +43,18 @@
 /**
  * This implementation of MetadataService reads Edges configuration from a file.
  * The layout of the file is as follows:
- * 
+ *
  * 
  * {
  *   edges: {
  *     [edgeId: string]: {
  *       comment: string,
  *       apikey: string
- *     } 
+ *     }
  *   }
  * }
  * 

- * 
+ *
  * 

  * This implementation does not require any login. It always serves the same
  * user, which has 'ADMIN'-permissions on all given Edges.
@@ -83,7 +83,7 @@ public FileMetadata() {
 	}
 
 	@Activate
-	void activate(Config config) {
+	private void activate(Config config) {
 		this.log.info("Activate [path=" + config.path() + "]");
 		this.path = config.path();
 
@@ -94,7 +94,7 @@ void activate(Config config) {
 	}
 
 	@Deactivate
-	void deactivate() {
+	private void deactivate() {
 		this.logInfo(this.log, "Deactivate");
 	}
 
@@ -120,7 +120,7 @@ public void logout(User user) {
 	public synchronized Optional getEdgeIdForApikey(String apikey) {
 		this.refreshData();
 		for (Entry entry : this.edges.entrySet()) {
-			MyEdge edge = entry.getValue();
+			var edge = entry.getValue();
 			if (edge.getApikey().equals(apikey)) {
 				return Optional.of(edge.getId());
 			}
@@ -160,9 +160,9 @@ public synchronized Collection getAllEdges() {
 	private synchronized void refreshData() {
 		if (this.edges.isEmpty()) {
 			// read file
-			StringBuilder sb = new StringBuilder();
+			var sb = new StringBuilder();
 			String line = null;
-			try (BufferedReader br = new BufferedReader(new FileReader(this.path))) {
+			try (var br = new BufferedReader(new FileReader(this.path))) {
 				while ((line = br.readLine()) != null) {
 					sb.append(line);
 				}
@@ -209,7 +209,7 @@ private synchronized void refreshData() {
 
 	private static User generateUser() {
 		return new User(FileMetadata.USER_ID, FileMetadata.USER_NAME, UUID.randomUUID().toString(),
-				FileMetadata.USER_GLOBAL_ROLE, new TreeMap<>(), LANGUAGE.name());
+				FileMetadata.USER_GLOBAL_ROLE, new TreeMap<>(), FileMetadata.LANGUAGE.name());
 	}
 
 	@Override
@@ -244,7 +244,7 @@ public void registerUser(JsonObject jsonObject) throws OpenemsNamedException {
 
 	@Override
 	public void updateUserLanguage(User user, Language locale) throws OpenemsNamedException {
-		LANGUAGE = locale;
+		FileMetadata.LANGUAGE = locale;
 	}
 
 }
diff --git a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/EdgeCache.java b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/EdgeCache.java
index 04efee92e20..821d8517972 100644
--- a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/EdgeCache.java
+++ b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/EdgeCache.java
@@ -15,7 +15,6 @@
 import io.openems.backend.metadata.odoo.Field.EdgeDevice;
 import io.openems.backend.metadata.odoo.odoo.FieldValue;
 import io.openems.backend.metadata.odoo.postgres.PgUtils;
-import io.openems.backend.metadata.odoo.postgres.QueueWriteWorker;
 import io.openems.backend.metadata.odoo.postgres.task.InsertEdgeConfigUpdate;
 import io.openems.backend.metadata.odoo.postgres.task.UpdateEdgeConfig;
 import io.openems.backend.metadata.odoo.postgres.task.UpdateEdgeProducttype;
@@ -37,17 +36,17 @@ public class EdgeCache {
 	/**
 	 * Map Edge-ID (String) to Edge.
 	 */
-	private Map edgeIdToEdge = new HashMap<>();
+	private final Map edgeIdToEdge = new HashMap<>();
 
 	/**
 	 * Map Odoo-ID (Integer) to Edge-ID (String).
 	 */
-	private Map odooIdToEdgeId = new HashMap<>();
+	private final Map odooIdToEdgeId = new HashMap<>();
 
 	/**
 	 * Map Apikey (String) to Edge-ID (String).
 	 */
-	private Map apikeyToEdgeId = new HashMap<>();
+	private final Map apikeyToEdgeId = new HashMap<>();
 
 	public EdgeCache(OdooMetadata parent) {
 		this.parent = parent;
@@ -55,7 +54,7 @@ public EdgeCache(OdooMetadata parent) {
 
 	/**
 	 * Adds a Edge or Updates an existing Edge from a SQL ResultSet.
-	 * 
+	 *
 	 * @param rs the ResultSet record
 	 * @return the new or updated Edge instance
 	 * @throws SQLException     on error
@@ -63,13 +62,13 @@ public EdgeCache(OdooMetadata parent) {
 	 */
 	public synchronized MyEdge addOrUpate(ResultSet rs) throws SQLException, OpenemsException {
 		// simple fields
-		String edgeId = PgUtils.getAsString(rs, EdgeDevice.NAME);
-		int odooId = PgUtils.getAsInt(rs, EdgeDevice.ID);
-		String apikey = PgUtils.getAsString(rs, EdgeDevice.APIKEY);
+		var edgeId = PgUtils.getAsString(rs, EdgeDevice.NAME);
+		var odooId = PgUtils.getAsInt(rs, EdgeDevice.ID);
+		var apikey = PgUtils.getAsString(rs, EdgeDevice.APIKEY);
 
 		// Config
 		EdgeConfig config;
-		String configString = PgUtils.getAsStringOrElse(rs, EdgeDevice.OPENEMS_CONFIG, "");
+		var configString = PgUtils.getAsStringOrElse(rs, EdgeDevice.OPENEMS_CONFIG, "");
 		if (configString.isEmpty()) {
 			config = new EdgeConfig();
 		} else {
@@ -85,10 +84,10 @@ public synchronized MyEdge addOrUpate(ResultSet rs) throws SQLException, Openems
 		}
 
 		// State
-		String stateString = PgUtils.getAsStringOrElse(rs, EdgeDevice.STATE, State.INACTIVE.name());
+		var stateString = PgUtils.getAsStringOrElse(rs, EdgeDevice.STATE, State.INACTIVE.name());
 		State state;
 		try {
-			state = State.valueOf(stateString.toUpperCase().replaceAll("-", "_"));
+			state = State.valueOf(stateString.toUpperCase().replace('-', '_'));
 		} catch (IllegalArgumentException e) {
 			this.parent.logWarn(this.log,
 					"Edge [" + edgeId + "]. Unable to get State from [" + stateString + "]: " + e.getMessage());
@@ -96,13 +95,13 @@ public synchronized MyEdge addOrUpate(ResultSet rs) throws SQLException, Openems
 		}
 
 		// more simple fields
-		String comment = PgUtils.getAsStringOrElse(rs, EdgeDevice.COMMENT, "");
-		String version = PgUtils.getAsStringOrElse(rs, EdgeDevice.OPENEMS_VERSION, "");
-		String productType = PgUtils.getAsStringOrElse(rs, EdgeDevice.PRODUCT_TYPE, "");
+		var comment = PgUtils.getAsStringOrElse(rs, EdgeDevice.COMMENT, "");
+		var version = PgUtils.getAsStringOrElse(rs, EdgeDevice.OPENEMS_VERSION, "");
+		var productType = PgUtils.getAsStringOrElse(rs, EdgeDevice.PRODUCT_TYPE, "");
 		int sumStateInt = PgUtils.getAsIntegerOrElse(rs, EdgeDevice.OPENEMS_SUM_STATE, -1);
-		Level sumState = Level.fromValue(sumStateInt).orElse(null);
+		var sumState = Level.fromValue(sumStateInt).orElse(null);
 
-		MyEdge edge = this.edgeIdToEdge.get(edgeId);
+		var edge = this.edgeIdToEdge.get(edgeId);
 		if (edge == null) {
 			// This is new -> create instance of Edge and register listeners
 			edge = new MyEdge(odooId, edgeId, apikey, comment, state, version, productType, sumState, config);
@@ -125,7 +124,7 @@ public synchronized MyEdge addOrUpate(ResultSet rs) throws SQLException, Openems
 
 	/**
 	 * Gets an Edge from its Edge-ID.
-	 * 
+	 *
 	 * @param edgeId the Edge-ID
 	 * @return the Edge, or null
 	 */
@@ -135,12 +134,12 @@ public synchronized MyEdge getEdgeFromEdgeId(String edgeId) {
 
 	/**
 	 * Gets an Edge from its Odoo-ID.
-	 * 
+	 *
 	 * @param odooId the Odoo-ID
 	 * @return the Edge, or null
 	 */
 	public synchronized MyEdge getEdgeFromOdooId(int odooId) {
-		String edgeId = this.odooIdToEdgeId.get(odooId);
+		var edgeId = this.odooIdToEdgeId.get(odooId);
 		if (edgeId == null) {
 			return null;
 		}
@@ -149,12 +148,12 @@ public synchronized MyEdge getEdgeFromOdooId(int odooId) {
 
 	/**
 	 * Gets an Edge from its Apikey.
-	 * 
+	 *
 	 * @param apikey the Apikey
 	 * @return the Edge, or null
 	 */
 	public synchronized MyEdge getEdgeForApikey(String apikey) {
-		String edgeId = this.apikeyToEdgeId.get(apikey);
+		var edgeId = this.apikeyToEdgeId.get(apikey);
 		if (edgeId == null) {
 			return null;
 		}
@@ -163,7 +162,7 @@ public synchronized MyEdge getEdgeForApikey(String apikey) {
 
 	/**
 	 * Gets all Edges as an unmodifiable Collection.
-	 * 
+	 *
 	 * @return a collection of Edges
 	 */
 	public Collection getAllEdges() {
@@ -172,7 +171,7 @@ public Collection getAllEdges() {
 
 	/**
 	 * Adds Listeners to act on changes to Edge.
-	 * 
+	 *
 	 * @param edge the Edge
 	 */
 	private void addListeners(MyEdge edge) {
@@ -187,7 +186,7 @@ private void addListeners(MyEdge edge) {
 							"Mark Edge [" + edge.getId() + "] as ACTIVE. It was [" + edge.getState().name() + "]");
 					edge.setState(State.ACTIVE);
 					this.parent.getPostgresHandler().getQueueWriteWorker();
-					QueueWriteWorker queueWriteWorker = this.parent.getPostgresHandler().getQueueWriteWorker();
+					var queueWriteWorker = this.parent.getPostgresHandler().getQueueWriteWorker();
 					queueWriteWorker.addTask(new UpdateEdgeStateActive(edge.getOdooId()));
 				}
 			} else {
@@ -197,14 +196,14 @@ private void addListeners(MyEdge edge) {
 		});
 		edge.onSetConfig(config -> {
 			// Update Edge Config in Odoo/Postgres
-			EdgeConfigDiff diff = EdgeConfigDiff.diff(config, edge.getConfig());
+			var diff = EdgeConfigDiff.diff(config, edge.getConfig());
 			if (!diff.isDifferent()) {
 				return;
 			}
 
 			this.parent.logInfo(this.log, "Edge [" + edge.getId() + "]. Update config: " + diff.toString());
 
-			QueueWriteWorker queueWriteWorker = this.parent.getPostgresHandler().getQueueWriteWorker();
+			var queueWriteWorker = this.parent.getPostgresHandler().getQueueWriteWorker();
 			queueWriteWorker.addTask(new UpdateEdgeConfig(edge.getOdooId(), config));
 			queueWriteWorker.addTask(new InsertEdgeConfigUpdate(edge.getOdooId(), diff));
 		});
@@ -221,7 +220,7 @@ private void addListeners(MyEdge edge) {
 			this.parent.logInfo(this.log, "Edge [" + edge.getId() + "]: Update OpenEMS Edge version to [" + version
 					+ "]. It was [" + edge.getVersion() + "]");
 			this.parent.odooHandler.writeEdge(edge,
-					new FieldValue(Field.EdgeDevice.OPENEMS_VERSION, version.toString()));
+					new FieldValue<>(Field.EdgeDevice.OPENEMS_VERSION, version.toString()));
 		});
 		edge.onSetSumState(sumState -> {
 			// Set Sum-State in Odoo/Postgres
diff --git a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/Field.java b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/Field.java
index cf1a4be5d8e..50e2f16ac1c 100644
--- a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/Field.java
+++ b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/Field.java
@@ -7,42 +7,42 @@ public interface Field {
 
 	/**
 	 * Gets the Field ID.
-	 * 
+	 *
 	 * @return the ID
 	 */
 	public String id();
 
 	/**
 	 * Gets the Field index.
-	 * 
+	 *
 	 * @return the index
 	 */
 	public int index();
 
 	/**
 	 * Gets the Field name.
-	 * 
+	 *
 	 * @return the name
 	 */
 	public String name();
 
 	/**
 	 * Should this Field be queried?.
-	 * 
+	 *
 	 * @return true if yes
 	 */
 	public boolean isQuery();
 
 	/**
 	 * Gets all fields that should be queried as a comma separated string.
-	 * 
+	 *
 	 * @param fields an array of {@link Field}s
 	 * @return the String
 	 */
 	public static String getSqlQueryFields(Field[] fields) {
 		return Stream.of(fields) //
-				.filter(f -> f.isQuery()) //
-				.map(f -> f.id()) //
+				.filter(Field::isQuery) //
+				.map(Field::id) //
 				.collect(Collectors.joining(","));
 	}
 
@@ -66,7 +66,7 @@ public enum EdgeDevice implements Field {
 		OPENEMS_IS_CONNECTED("openems_is_connected", false);
 
 		public static final String ODOO_MODEL = "openems.edge";
-		public static final String ODOO_TABLE = ODOO_MODEL.replace(".", "_");
+		public static final String ODOO_TABLE = EdgeDevice.ODOO_MODEL.replace(".", "_");
 
 		private static final class StaticFields {
 			private static int nextQueryIndex = 1;
@@ -99,6 +99,7 @@ public int index() {
 			return this.queryIndex;
 		}
 
+		@Override
 		public boolean isQuery() {
 			return this.query;
 		}
@@ -119,7 +120,7 @@ public enum EdgeDeviceStatus implements Field {
 		ACKNOWLEDGE_DAYS("acknowledge_days", false);
 
 		public static final String ODOO_MODEL = "openems.edge_status";
-		public static final String ODOO_TABLE = ODOO_MODEL.replace(".", "_");
+		public static final String ODOO_TABLE = EdgeDeviceStatus.ODOO_MODEL.replace(".", "_");
 
 		private static final class StaticFields {
 			private static int nextQueryIndex = 1;
@@ -153,6 +154,7 @@ public int index() {
 			return this.queryIndex;
 		}
 
+		@Override
 		public boolean isQuery() {
 			return this.query;
 		}
@@ -168,7 +170,7 @@ public enum EdgeConfigUpdate implements Field {
 		DETAILS("details", false);
 
 		public static final String ODOO_MODEL = "openems.openemsconfigupdate";
-		public static final String ODOO_TABLE = ODOO_MODEL.replace(".", "_");
+		public static final String ODOO_TABLE = EdgeConfigUpdate.ODOO_MODEL.replace(".", "_");
 
 		private static final class StaticFields {
 			private static int nextQueryIndex = 1;
@@ -202,6 +204,7 @@ public int index() {
 			return this.queryIndex;
 		}
 
+		@Override
 		public boolean isQuery() {
 			return this.query;
 		}
@@ -217,7 +220,7 @@ public enum EdgeDeviceUserRole implements Field {
 		ROLE("role", false);
 
 		public static final String ODOO_MODEL = "openems.edge_user_role";
-		public static final String ODOO_TABLE = ODOO_MODEL.replace(".", "_");
+		public static final String ODOO_TABLE = EdgeDeviceUserRole.ODOO_MODEL.replace(".", "_");
 
 		private static final class StaticFields {
 			private static int nextQueryIndex = 1;
@@ -268,7 +271,7 @@ public enum User implements Field {
 		OPENEMS_LANGUAGE("openems_language", true);
 
 		public static final String ODOO_MODEL = "res.users";
-		public static final String ODOO_TABLE = ODOO_MODEL.replace(".", "_");
+		public static final String ODOO_TABLE = User.ODOO_MODEL.replace(".", "_");
 
 		private static final class StaticFields {
 			private static int nextQueryIndex = 1;
@@ -327,7 +330,7 @@ public enum Partner implements Field {
 		LANGUAGE("lang", true);
 
 		public static final String ODOO_MODEL = "res.partner";
-		public static final String ODOO_TABLE = ODOO_MODEL.replace(".", "_");
+		public static final String ODOO_TABLE = Partner.ODOO_MODEL.replace(".", "_");
 
 		private static final class StaticFields {
 			private static int nextQueryIndex = 1;
@@ -374,7 +377,7 @@ public enum Country implements Field {
 		CODE("code", true);
 
 		public static final String ODOO_MODEL = "res.country";
-		public static final String ODOO_TABLE = ODOO_MODEL.replace(".", "_");
+		public static final String ODOO_TABLE = Country.ODOO_MODEL.replace(".", "_");
 
 		private static final class StaticFields {
 			private static int nextQueryIndex = 1;
@@ -422,7 +425,7 @@ public enum SetupProtocol implements Field {
 		EDGE("edge_id", true);
 
 		public static final String ODOO_MODEL = "openems.setup_protocol";
-		public static final String ODOO_TABLE = ODOO_MODEL.replace(".", "_");
+		public static final String ODOO_TABLE = SetupProtocol.ODOO_MODEL.replace(".", "_");
 
 		private static final class StaticFields {
 			private static int nextQueryIndex = 1;
@@ -469,7 +472,7 @@ public enum SetupProtocolProductionLot implements Field {
 		LOT("lot_id", true);
 
 		public static final String ODOO_MODEL = "openems.setup_protocol_production_lot";
-		public static final String ODOO_TABLE = ODOO_MODEL.replace(".", "_");
+		public static final String ODOO_TABLE = SetupProtocolProductionLot.ODOO_MODEL.replace(".", "_");
 
 		private static final class StaticFields {
 			private static int nextQueryIndex = 1;
@@ -515,7 +518,7 @@ public enum SetupProtocolItem implements Field {
 		SEQUENCE("sequence", true);
 
 		public static final String ODOO_MODEL = "openems.setup_protocol_item";
-		public static final String ODOO_TABLE = ODOO_MODEL.replace(".", "_");
+		public static final String ODOO_TABLE = SetupProtocolItem.ODOO_MODEL.replace(".", "_");
 
 		private static final class StaticFields {
 			private static int nextQueryIndex = 1;
@@ -561,7 +564,7 @@ public enum StockProductionLot implements Field {
 		PRODUCT("product_id", true);
 
 		public static final String ODOO_MODEL = "stock.production.lot";
-		public static final String ODOO_TABLE = ODOO_MODEL.replace(".", "_");
+		public static final String ODOO_TABLE = StockProductionLot.ODOO_MODEL.replace(".", "_");
 
 		private static final class StaticFields {
 			private static int nextQueryIndex = 1;
diff --git a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/MyUser.java b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/MyUser.java
index e004fa73d5a..4e97300a742 100644
--- a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/MyUser.java
+++ b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/MyUser.java
@@ -17,7 +17,7 @@ public MyUser(int odooId, String login, String name, String token, Role globalRo
 
 	/**
 	 * Gets the internal Odoo record ID.
-	 * 
+	 *
 	 * @return the odoo id
 	 */
 	public int getOdooId() {
diff --git a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/OdooMetadata.java b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/OdooMetadata.java
index f3133bab0b3..b4361fdbb67 100644
--- a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/OdooMetadata.java
+++ b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/OdooMetadata.java
@@ -16,7 +16,6 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import com.google.gson.JsonArray;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
 
@@ -28,8 +27,8 @@
 import io.openems.backend.metadata.odoo.odoo.OdooUserRole;
 import io.openems.backend.metadata.odoo.postgres.PostgresHandler;
 import io.openems.common.exceptions.OpenemsError.OpenemsNamedException;
-import io.openems.common.jsonrpc.request.UpdateUserLanguageRequest.Language;
 import io.openems.common.exceptions.OpenemsException;
+import io.openems.common.jsonrpc.request.UpdateUserLanguageRequest.Language;
 import io.openems.common.session.Role;
 import io.openems.common.utils.JsonUtils;
 
@@ -49,7 +48,7 @@ public class OdooMetadata extends AbstractMetadata implements Metadata {
 	/**
 	 * Maps User-ID to {@link User}.
 	 */
-	private ConcurrentHashMap users = new ConcurrentHashMap<>();
+	private final ConcurrentHashMap users = new ConcurrentHashMap<>();
 
 	public OdooMetadata() {
 		super("Metadata.Odoo");
@@ -58,7 +57,7 @@ public OdooMetadata() {
 	}
 
 	@Activate
-	void activate(Config config) throws SQLException {
+	private void activate(Config config) throws SQLException {
 		this.logInfo(this.log, "Activate. " //
 				+ "Odoo [" + config.odooHost() + ":" + config.odooPort() + ";PW "
 				+ (config.odooPassword() != null ? "ok" : "NOT_SET") + "] " //
@@ -73,7 +72,7 @@ void activate(Config config) throws SQLException {
 	}
 
 	@Deactivate
-	void deactivate() {
+	private void deactivate() {
 		this.logInfo(this.log, "Deactivate");
 		if (this.postgresHandler != null) {
 			this.postgresHandler.deactivate();
@@ -97,17 +96,17 @@ public User authenticate(String sessionId) throws OpenemsNamedException {
 		JsonObject result = this.odooHandler.authenticateSession(sessionId);
 
 		// Parse Result
-		JsonArray jDevices = JsonUtils.getAsJsonArray(result, "devices");
+		var jDevices = JsonUtils.getAsJsonArray(result, "devices");
 		NavigableMap roles = new TreeMap<>();
 		for (JsonElement device : jDevices) {
-			String edgeId = JsonUtils.getAsString(device, "name");
-			Role role = Role.getRole(JsonUtils.getAsString(device, "role"));
+			var edgeId = JsonUtils.getAsString(device, "name");
+			var role = Role.getRole(JsonUtils.getAsString(device, "role"));
 			roles.put(edgeId, role);
 		}
-		JsonObject jUser = JsonUtils.getAsJsonObject(result, "user");
-		int odooUserId = JsonUtils.getAsInt(jUser, "id");
+		var jUser = JsonUtils.getAsJsonObject(result, "user");
+		var odooUserId = JsonUtils.getAsInt(jUser, "id");
 
-		MyUser user = new MyUser(//
+		var user = new MyUser(//
 				odooUserId, //
 				JsonUtils.getAsString(jUser, "login"), //
 				JsonUtils.getAsString(jUser, "name"), //
@@ -127,17 +126,16 @@ public void logout(User user) {
 
 	@Override
 	public Optional getEdgeIdForApikey(String apikey) {
-		Optional edge = this.postgresHandler.getEdgeForApikey(apikey);
-		if (edge.isPresent()) {
-			return Optional.of(edge.get().getId());
-		} else {
-			return Optional.empty();
+		var edgeOpt = this.postgresHandler.getEdgeForApikey(apikey);
+		if (edgeOpt.isPresent()) {
+			return Optional.of(edgeOpt.get().getId());
 		}
+		return Optional.empty();
 	}
 
 	@Override
 	public Optional getEdgeBySetupPassword(String setupPassword) {
-		Optional optEdgeId = this.odooHandler.getEdgeIdBySetupPassword(setupPassword);
+		var optEdgeId = this.odooHandler.getEdgeIdBySetupPassword(setupPassword);
 		if (!optEdgeId.isPresent()) {
 			return Optional.empty();
 		}
@@ -161,7 +159,7 @@ public Collection getAllEdges() {
 
 	/**
 	 * Gets the {@link OdooHandler}.
-	 * 
+	 *
 	 * @return the {@link OdooHandler}
 	 */
 	public OdooHandler getOdooHandler() {
@@ -170,7 +168,7 @@ public OdooHandler getOdooHandler() {
 
 	/**
 	 * Gets the {@link PostgresHandler}.
-	 * 
+	 *
 	 * @return the {@link PostgresHandler}
 	 */
 	public PostgresHandler getPostgresHandler() {
@@ -219,11 +217,13 @@ public int submitSetupProtocol(User user, JsonObject jsonObject) throws OpenemsN
 
 	@Override
 	public void registerUser(JsonObject jsonObject) throws OpenemsNamedException {
-		OdooUserRole role = OdooUserRole.OWNER;
+		final OdooUserRole role;
 
-		Optional optRole = JsonUtils.getAsOptionalString(jsonObject, "role");
-		if (optRole.isPresent()) {
-			role = OdooUserRole.getRole(optRole.get());
+		var roleOpt = JsonUtils.getAsOptionalString(jsonObject, "role");
+		if (roleOpt.isPresent()) {
+			role = OdooUserRole.getRole(roleOpt.get());
+		} else {
+			role = OdooUserRole.OWNER;
 		}
 
 		this.odooHandler.registerUser(jsonObject, role);
diff --git a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/odoo/Credentials.java b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/odoo/Credentials.java
index 969469cce57..8702c15cf1e 100644
--- a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/odoo/Credentials.java
+++ b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/odoo/Credentials.java
@@ -9,7 +9,7 @@ public class Credentials {
 
 	/**
 	 * Creates {@link Credentials} from a {@link Config}uration.
-	 * 
+	 *
 	 * @param config the configuration
 	 * @return a new {@link Credentials} object
 	 */
diff --git a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/odoo/FieldValue.java b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/odoo/FieldValue.java
index 3bddbb1804d..3a6b88d5a41 100644
--- a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/odoo/FieldValue.java
+++ b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/odoo/FieldValue.java
@@ -32,7 +32,7 @@ public String toString() {
 		} else {
 			string = this.value.toString();
 		}
-		string = string.replaceAll("\n", "");
+		string = string.replace("\n", "");
 		return this.field.id() + ":" + string;
 	}
 }
diff --git a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/odoo/OdooHandler.java b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/odoo/OdooHandler.java
index 2ba3a905269..5c66193001d 100644
--- a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/odoo/OdooHandler.java
+++ b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/odoo/OdooHandler.java
@@ -46,7 +46,7 @@ public OdooHandler(OdooMetadata parent, Config config) {
 
 	/**
 	 * Writes one field to Odoo Edge model.
-	 * 
+	 *
 	 * @param edge        the Edge
 	 * @param fieldValues the FieldValues
 	 */
@@ -57,14 +57,14 @@ public void writeEdge(MyEdge edge, FieldValue... fieldValues) {
 		} catch (OpenemsException e) {
 			this.parent.logError(this.log, "Unable to update Edge [" + edge.getId() + "] " //
 					+ "Odoo-ID [" + edge.getOdooId() + "] " //
-					+ "Fields [" + Stream.of(fieldValues).map(v -> v.toString()).collect(Collectors.joining(","))
+					+ "Fields [" + Stream.of(fieldValues).map(FieldValue::toString).collect(Collectors.joining(","))
 					+ "]: " + e.getMessage());
 		}
 	}
 
 	/**
 	 * Adds a message in Odoo Chatter ('mail.thread').
-	 * 
+	 *
 	 * @param edge    the Edge
 	 * @param message the message
 	 */
@@ -80,12 +80,12 @@ public void addChatterMessage(MyEdge edge, String message) {
 
 	/**
 	 * Returns Edge by setupPassword, otherwise an empty {@link Optional}.
-	 * 
+	 *
 	 * @param setupPassword to find Edge
 	 * @return Edge or empty {@link Optional}
 	 */
 	public Optional getEdgeIdBySetupPassword(String setupPassword) {
-		Domain filter = new Domain(Field.EdgeDevice.SETUP_PASSWORD, "=", setupPassword);
+		var filter = new Domain(Field.EdgeDevice.SETUP_PASSWORD, "=", setupPassword);
 
 		try {
 			int[] search = OdooUtils.search(this.credentials, Field.EdgeDevice.ODOO_MODEL, filter);
@@ -96,7 +96,7 @@ public Optional getEdgeIdBySetupPassword(String setupPassword) {
 			Map read = OdooUtils.readOne(this.credentials, Field.EdgeDevice.ODOO_MODEL, search[0],
 					Field.EdgeDevice.NAME);
 
-			String name = (String) read.get(Field.EdgeDevice.NAME.id());
+			var name = (String) read.get(Field.EdgeDevice.NAME.id());
 			if (name == null) {
 				return Optional.empty();
 			}
@@ -112,7 +112,7 @@ public Optional getEdgeIdBySetupPassword(String setupPassword) {
 	/**
 	 * Assigns the given user with given {@link OdooUserRole} to the Edge. If Edge
 	 * already assigned to user exit method.
-	 * 
+	 *
 	 * @param user     the Odoo user
 	 * @param edge     the Odoo edge
 	 * @param userRole the Odoo user role
@@ -126,7 +126,7 @@ public void assignEdgeToUser(MyUser user, MyEdge edge, OdooUserRole userRole) th
 	/**
 	 * Assigns the given user with given {@link OdooUserRole} to the Edge. If Edge
 	 * already assigned to user exit method.
-	 * 
+	 *
 	 * @param userId   the Odoo user id
 	 * @param edgeId   the Odoo edge
 	 * @param userRole the Odoo user role
@@ -142,14 +142,14 @@ private void assignEdgeToUser(int userId, int edgeId, OdooUserRole userRole) thr
 		}
 
 		OdooUtils.create(this.credentials, Field.EdgeDeviceUserRole.ODOO_MODEL, //
-				new FieldValue(Field.EdgeDeviceUserRole.USER_ID, userId), //
-				new FieldValue(Field.EdgeDeviceUserRole.DEVICE_ID, edgeId), //
-				new FieldValue(Field.EdgeDeviceUserRole.ROLE, userRole.getOdooRole()));
+				new FieldValue<>(Field.EdgeDeviceUserRole.USER_ID, userId), //
+				new FieldValue<>(Field.EdgeDeviceUserRole.DEVICE_ID, edgeId), //
+				new FieldValue<>(Field.EdgeDeviceUserRole.ROLE, userRole.getOdooRole()));
 	}
 
 	/**
 	 * Authenticates a user using Username and Password.
-	 * 
+	 *
 	 * @param username the Username
 	 * @param password the Password
 	 * @return the session_id
@@ -161,7 +161,7 @@ public String authenticate(String username, String password) throws OpenemsNamed
 
 	/**
 	 * Authenticates a user using a Session-ID.
-	 * 
+	 *
 	 * @param sessionId the Odoo Session-ID
 	 * @return the {@link JsonObject} received from /openems_backend/info.
 	 * @throws OpenemsNamedException on error
@@ -174,7 +174,7 @@ public JsonObject authenticateSession(String sessionId) throws OpenemsNamedExcep
 
 	/**
 	 * Logout a User.
-	 * 
+	 *
 	 * @param sessionId the Session-ID
 	 * @throws OpenemsNamedException on error
 	 */
@@ -189,12 +189,12 @@ public void logout(String sessionId) {
 
 	/**
 	 * Get field from the 'Set-Cookie' field in HTTP headers.
-	 * 
+	 *
 	 * 

 	 * Per specification
 	 * all variants of 'cookie' are accepted.
-	 * 
+	 *
 	 * @param headers   the HTTP headers
 	 * @param fieldname the field name
 	 * @return value as optional
@@ -220,13 +220,13 @@ public static Optional getFieldFromSetCookieHeader(Map getUserInformation(MyUser user) throws OpenemsNamedException {
-		int partnerId = this.getOdooPartnerId(user);
+		var partnerId = this.getOdooPartnerId(user);
 
 		Map odooPartner = OdooUtils.readOne(this.credentials, Field.Partner.ODOO_MODEL, partnerId,
 				Field.Partner.FIRSTNAME, //
@@ -244,8 +244,8 @@ public Map getUserInformation(MyUser user) throws OpenemsNamedEx
 			Map countryCode = OdooUtils.readOne(this.credentials, Field.Country.ODOO_MODEL,
 					(Integer) odooCountryId[0], Field.Country.CODE);
 
-			Optional optCode = ObjectUtils.getAsOptionalString(countryCode.get("code"));
-			if (optCode.isPresent()) {
+			var codeOpt = ObjectUtils.getAsOptionalString(countryCode.get("code"));
+			if (codeOpt.isPresent()) {
 				Object[] countryElement = Arrays.copyOf(odooCountryId, odooCountryId.length + 1);
 				countryElement[2] = countryCode.get("code");
 
@@ -258,7 +258,7 @@ public Map getUserInformation(MyUser user) throws OpenemsNamedEx
 
 	/**
 	 * Update the given {@link MyUser} with information from {@link JsonObject}.
-	 * 
+	 *
 	 * @param user     the {@link MyUser} to update
 	 * @param userJson the {@link JsonObject} information to update
 	 * @throws OpenemsException on error
@@ -277,23 +277,23 @@ public void setUserInformation(MyUser user, JsonObject userJson) throws OpenemsN
 		JsonUtils.getAsOptionalString(userJson, "phone") //
 				.ifPresent(phone -> fieldValues.put(Field.Partner.PHONE.id(), phone));
 
-		int odooPartnerId = this.getOdooPartnerId(user.getOdooId());
+		var odooPartnerId = this.getOdooPartnerId(user.getOdooId());
 		OdooUtils.write(this.credentials, Field.Partner.ODOO_MODEL, new Integer[] { odooPartnerId }, fieldValues);
 	}
 
 	/**
 	 * Get address to update for an Odoo user.
-	 * 
+	 *
 	 * @param addressJson {@link JsonObject} to get the fields to update
 	 * @return Fields to update
 	 * @throws OpenemsException on error
 	 */
 	private Map updateAddress(JsonObject addressJson) throws OpenemsException {
-		Optional optAddress = JsonUtils.getAsOptionalJsonObject(addressJson, "address");
-		if (!optAddress.isPresent()) {
+		var addressOpt = JsonUtils.getAsOptionalJsonObject(addressJson, "address");
+		if (!addressOpt.isPresent()) {
 			return new HashMap<>();
 		}
-		JsonObject address = optAddress.get();
+		var address = addressOpt.get();
 
 		Map addressFields = new HashMap<>();
 		addressFields.put("type", "private");
@@ -304,9 +304,9 @@ private Map updateAddress(JsonObject addressJson) throws Openems
 		JsonUtils.getAsOptionalString(address, "city") //
 				.ifPresent(city -> addressFields.put(Field.Partner.CITY.id(), city));
 
-		Optional optCountryCode = JsonUtils.getAsOptionalString(address, "country");
-		if (optCountryCode.isPresent()) {
-			String countryCode = optCountryCode.get().toUpperCase();
+		var countryCodeOpt = JsonUtils.getAsOptionalString(address, "country");
+		if (countryCodeOpt.isPresent()) {
+			var countryCode = countryCodeOpt.get().toUpperCase();
 
 			int[] countryFound = OdooUtils.search(this.credentials, Field.Country.ODOO_MODEL, //
 					new Domain(Field.Country.CODE, "=", countryCode));
@@ -324,7 +324,7 @@ private Map updateAddress(JsonObject addressJson) throws Openems
 	 * Get company to update for an Odoo user. Checks if the given company exits in
 	 * Odoo and assign the company to the Odoo user. Otherwise a new company will be
 	 * created in Odoo.
-	 * 
+	 *
 	 * @param companyJson {@link JsonObject} to get the fields to update
 	 * @return Fields to update
 	 * @throws OpenemsException on error
@@ -338,32 +338,32 @@ private Map updateCompany(JsonObject companyJson) throws Openems
 	 * users company with the new company name for equality. Both are equal nothing
 	 * to update. Otherwise the new company will be assigned to the user or the new
 	 * company will be created in Odoo.
-	 * 
+	 *
 	 * @param user        {@link MyUser} to check company name
 	 * @param companyJson {@link JsonObject} to get the fields to update
 	 * @return Fields to update
 	 * @throws OpenemsException on error
 	 */
 	private Map updateCompany(MyUser user, JsonObject companyJson) throws OpenemsException {
-		Optional optCompany = JsonUtils.getAsOptionalJsonObject(companyJson, "company");
-		if (!optCompany.isPresent()) {
+		var companyOpt = JsonUtils.getAsOptionalJsonObject(companyJson, "company");
+		if (!companyOpt.isPresent()) {
 			return new HashMap<>();
 		}
-		Optional optCompanyName = JsonUtils.getAsOptionalString(optCompany.get(), "name");
-		if (!optCompanyName.isPresent()) {
+		var companyNameOpt = JsonUtils.getAsOptionalString(companyOpt.get(), "name");
+		if (!companyNameOpt.isPresent()) {
 			return new HashMap<>();
 		}
-		String jsonCompanyName = optCompanyName.get();
+		var jCompanyName = companyNameOpt.get();
 
 		if (user != null) {
 			Map odooPartner = OdooUtils.readOne(this.credentials, Field.Partner.ODOO_MODEL, //
 					this.getOdooPartnerId(user.getOdooId()), //
 					Field.Partner.COMPANY_NAME);
 
-			Optional optPartnerCompanyName = ObjectUtils
+			var partnerCompanyNameOpt = ObjectUtils
 					.getAsOptionalString(odooPartner.get(Field.Partner.COMPANY_NAME.id()));
-			if (optPartnerCompanyName.isPresent()) {
-				if (jsonCompanyName.equals(optPartnerCompanyName.get())) {
+			if (partnerCompanyNameOpt.isPresent()) {
+				if (jCompanyName.equals(partnerCompanyNameOpt.get())) {
 					return new HashMap<>();
 				}
 			}
@@ -371,7 +371,7 @@ private Map updateCompany(MyUser user, JsonObject companyJson) t
 
 		int[] companyFound = OdooUtils.search(this.credentials, Field.Partner.ODOO_MODEL, //
 				new Domain(Field.Partner.IS_COMPANY, "=", true),
-				new Domain(Field.Partner.COMPANY_NAME, "=", jsonCompanyName));
+				new Domain(Field.Partner.COMPANY_NAME, "=", jCompanyName));
 
 		Map companyFields = new HashMap<>();
 		if (companyFound.length > 0) {
@@ -379,7 +379,7 @@ private Map updateCompany(MyUser user, JsonObject companyJson) t
 		} else {
 			int createdCompany = OdooUtils.create(this.credentials, Field.Partner.ODOO_MODEL, //
 					new FieldValue<>(Field.Partner.IS_COMPANY, true),
-					new FieldValue<>(Field.Partner.NAME, jsonCompanyName));
+					new FieldValue<>(Field.Partner.NAME, jCompanyName));
 			companyFields.put(Field.Partner.PARENT.id(), createdCompany);
 		}
 
@@ -388,7 +388,7 @@ private Map updateCompany(MyUser user, JsonObject companyJson) t
 
 	/**
 	 * Returns the Odoo report for a setup protocol.
-	 * 
+	 *
 	 * @param setupProtocolId the Odoo setup protocol id
 	 * @return report as a byte array
 	 * @throws OpenemsNamedException on error
@@ -399,31 +399,31 @@ public byte[] getOdooSetupProtocolReport(int setupProtocolId) throws OpenemsName
 
 	/**
 	 * Save the Setup Protocol to Odoo.
-	 * 
+	 *
 	 * @param user              {@link MyUser} current user
 	 * @param setupProtocolJson {@link SetupProtocol} the setup protocol
 	 * @return the Setup Protocol ID
 	 * @throws OpenemsNamedException on error
 	 */
 	public int submitSetupProtocol(MyUser user, JsonObject setupProtocolJson) throws OpenemsNamedException {
-		JsonObject userJson = JsonUtils.getAsJsonObject(setupProtocolJson, "customer");
-		JsonObject edgeJson = JsonUtils.getAsJsonObject(setupProtocolJson, "edge");
+		var userJson = JsonUtils.getAsJsonObject(setupProtocolJson, "customer");
+		var edgeJson = JsonUtils.getAsJsonObject(setupProtocolJson, "edge");
 
-		String edgeId = JsonUtils.getAsString(edgeJson, "id");
+		var edgeId = JsonUtils.getAsString(edgeJson, "id");
 		int[] foundEdge = OdooUtils.search(this.credentials, Field.EdgeDevice.ODOO_MODEL,
 				new Domain(Field.EdgeDevice.NAME, "=", edgeId));
 		if (foundEdge.length != 1) {
 			throw new OpenemsException("Edge not found for id [" + edgeId + "]");
 		}
 
-		String password = PasswordUtils.generateRandomPassword(24);
-		int odooUserId = this.createOdooUser(userJson, password);
+		var password = PasswordUtils.generateRandomPassword(24);
+		var odooUserId = this.createOdooUser(userJson, password);
 
-		int customerId = this.getOdooPartnerId(odooUserId);
-		int installerId = this.getOdooPartnerId(user);
+		var customerId = this.getOdooPartnerId(odooUserId);
+		var installerId = this.getOdooPartnerId(user);
 		this.assignEdgeToUser(odooUserId, foundEdge[0], OdooUserRole.OWNER);
 
-		int protocolId = this.createSetupProtocol(setupProtocolJson, foundEdge[0], customerId, installerId);
+		var protocolId = this.createSetupProtocol(setupProtocolJson, foundEdge[0], customerId, installerId);
 
 		try {
 			this.sendSetupProtocolMail(user, protocolId, edgeId);
@@ -436,7 +436,7 @@ public int submitSetupProtocol(MyUser user, JsonObject setupProtocolJson) throws
 
 	/**
 	 * Call Odoo api to send mail via Odoo.
-	 * 
+	 *
 	 * @param user       the Odoo user
 	 * @param protocolId the Odoo setup protocol id
 	 * @param edgeId     the Odoo edge
@@ -455,7 +455,7 @@ private void sendSetupProtocolMail(MyUser user, int protocolId, String edgeId) t
 	/**
 	 * Create an Odoo user and return thats id. If user already exists the user will
 	 * be updated and return the user id.
-	 * 
+	 *
 	 * @param userJson the {@link Partner} to create user
 	 * @param password the password to set for the new user
 	 * @return the Odoo user id
@@ -471,7 +471,7 @@ private int createOdooUser(JsonObject userJson, String password) throws OpenemsN
 		JsonUtils.getAsOptionalString(userJson, "lastname") //
 				.ifPresent(lastname -> customerFields.put(Field.Partner.LASTNAME.id(), lastname));
 
-		String email = JsonUtils.getAsString(userJson, "email");
+		var email = JsonUtils.getAsString(userJson, "email");
 		JsonUtils.getAsOptionalString(userJson, "email") //
 				.ifPresent(mail -> customerFields.put(Field.Partner.EMAIL.id(), mail));
 		JsonUtils.getAsOptionalString(userJson, "phone") //
@@ -481,24 +481,23 @@ private int createOdooUser(JsonObject userJson, String password) throws OpenemsN
 				new Domain(Field.User.LOGIN, "=", email));
 
 		if (userFound.length == 1) {
-			int userId = userFound[0];
+			var userId = userFound[0];
 			OdooUtils.write(this.credentials, Field.User.ODOO_MODEL, new Integer[] { userId }, customerFields);
 			return userId;
-		} else {
-			customerFields.put(Field.User.LOGIN.id(), email);
-			customerFields.put(Field.User.PASSWORD.id(), password);
-			customerFields.put(Field.User.GLOBAL_ROLE.id(), OdooUserRole.OWNER.getOdooRole());
-			customerFields.put(Field.User.GROUPS.id(), OdooUserRole.OWNER.toOdooIds());
-			int createdUserId = OdooUtils.create(this.credentials, Field.User.ODOO_MODEL, customerFields);
-
-			this.sendRegistrationMail(createdUserId, password);
-			return createdUserId;
 		}
+		customerFields.put(Field.User.LOGIN.id(), email);
+		customerFields.put(Field.User.PASSWORD.id(), password);
+		customerFields.put(Field.User.GLOBAL_ROLE.id(), OdooUserRole.OWNER.getOdooRole());
+		customerFields.put(Field.User.GROUPS.id(), OdooUserRole.OWNER.toOdooIds());
+		var createdUserId = OdooUtils.create(this.credentials, Field.User.ODOO_MODEL, customerFields);
+
+		this.sendRegistrationMail(createdUserId, password);
+		return createdUserId;
 	}
 
 	/**
 	 * Create a setup protocol in Odoo.
-	 * 
+	 *
 	 * @param jsonObject  {@link SetupProtocol} to create
 	 * @param edgeId      the Edge-ID
 	 * @param customerId  Odoo customer id to set
@@ -510,9 +509,9 @@ private int createSetupProtocol(JsonObject jsonObject, int edgeId, int customerI
 			throws OpenemsException {
 		Integer locationId = null;
 
-		Optional jsonLocation = JsonUtils.getAsOptionalJsonObject(jsonObject, "location");
-		if (jsonLocation.isPresent()) {
-			JsonObject location = jsonLocation.get();
+		var jLocationOpt = JsonUtils.getAsOptionalJsonObject(jsonObject, "location");
+		if (jLocationOpt.isPresent()) {
+			JsonObject location = jLocationOpt.get();
 
 			Map locationFields = new HashMap<>();
 			locationFields.putAll(this.updateAddress(location));
@@ -538,13 +537,13 @@ private int createSetupProtocol(JsonObject jsonObject, int edgeId, int customerI
 
 		int setupProtocolId = OdooUtils.create(this.credentials, Field.SetupProtocol.ODOO_MODEL, setupProtocolFields);
 
-		Optional lots = JsonUtils.getAsOptionalJsonArray(jsonObject, "lots");
-		if (lots.isPresent()) {
-			this.createSetupProtocolProductionLots(setupProtocolId, lots.get());
+		var lotsOpt = JsonUtils.getAsOptionalJsonArray(jsonObject, "lots");
+		if (lotsOpt.isPresent()) {
+			this.createSetupProtocolProductionLots(setupProtocolId, lotsOpt.get());
 		}
-		Optional items = JsonUtils.getAsOptionalJsonArray(jsonObject, "items");
-		if (items.isPresent()) {
-			this.createSetupProtocolItems(setupProtocolId, items.get());
+		var itemsOpt = JsonUtils.getAsOptionalJsonArray(jsonObject, "items");
+		if (itemsOpt.isPresent()) {
+			this.createSetupProtocolItems(setupProtocolId, itemsOpt.get());
 		}
 
 		return setupProtocolId;
@@ -552,7 +551,7 @@ private int createSetupProtocol(JsonObject jsonObject, int edgeId, int customerI
 
 	/**
 	 * Create production lots for the given setup protocol id.
-	 * 
+	 *
 	 * @param setupProtocolId assign to the lots
 	 * @param lots            list of setup protocol production lots to create
 	 * @throws OpenemsException on error
@@ -571,10 +570,10 @@ private void createSetupProtocolProductionLots(int setupProtocolId, JsonArray lo
 			JsonUtils.getAsOptionalString(lot, "name") //
 					.ifPresent(name -> lotFields.put("name", name));
 
-			Optional optSerialNumber = JsonUtils.getAsOptionalString(lot, "serialNumber");
-			if (optSerialNumber.isPresent()) {
+			var serialNumberOpt = JsonUtils.getAsOptionalString(lot, "serialNumber");
+			if (serialNumberOpt.isPresent()) {
 				int[] lotId = OdooUtils.search(this.credentials, Field.StockProductionLot.ODOO_MODEL, //
-						new Domain(Field.StockProductionLot.SERIAL_NUMBER, "=", optSerialNumber.get()));
+						new Domain(Field.StockProductionLot.SERIAL_NUMBER, "=", serialNumberOpt.get()));
 
 				if (lotId.length > 0) {
 					lotFields.put(Field.SetupProtocolProductionLot.LOT.id(), lotId[0]);
@@ -592,7 +591,7 @@ private void createSetupProtocolProductionLots(int setupProtocolId, JsonArray lo
 	/**
 	 * Create for the given serial numbers that were not found a
 	 * {@link SetupProtocolItem}.
-	 * 
+	 *
 	 * @param setupProtocolId the protocol id
 	 * @param serialNumbers   not found serial numbers
 	 * @throws OpenemsException on error
@@ -617,7 +616,7 @@ private void createNotFoundSerialNumbers(int setupProtocolId, List
 
 	/**
 	 * Create items for the given setup protocol id.
-	 * 
+	 *
 	 * @param setupProtocolId assign to the items
 	 * @param items           list of setup protocol items to create
 	 * @throws OpenemsException on error
@@ -643,7 +642,7 @@ private void createSetupProtocolItems(int setupProtocolId, JsonArray items) thro
 
 	/**
 	 * Gets the referenced Odoo partner id for an Odoo user.
-	 * 
+	 *
 	 * @param user the Odoo user
 	 * @return the Odoo partner id
 	 * @throws OpenemsException on error
@@ -654,7 +653,7 @@ private int getOdooPartnerId(MyUser user) throws OpenemsException {
 
 	/**
 	 * Gets the referenced Odoo partner id for an Odoo user id.
-	 * 
+	 *
 	 * @param odooUserId of the Odoo user
 	 * @return the Odoo partner id
 	 * @throws OpenemsException on error
@@ -663,28 +662,28 @@ private int getOdooPartnerId(int odooUserId) throws OpenemsException {
 		Map odooUser = OdooUtils.readOne(this.credentials, Field.User.ODOO_MODEL, odooUserId,
 				Field.User.PARTNER);
 
-		Optional odooPartnerId = OdooUtils.getOdooRefernceId(odooUser.get(Field.User.PARTNER.id()));
+		var odooPartnerIdOpt = OdooUtils.getOdooReferenceId(odooUser.get(Field.User.PARTNER.id()));
 
-		if (!odooPartnerId.isPresent()) {
+		if (!odooPartnerIdOpt.isPresent()) {
 			throw new OpenemsException("Odoo partner not found for user ['" + odooUserId + "']");
 		}
 
-		return odooPartnerId.get();
+		return odooPartnerIdOpt.get();
 	}
 
 	/**
 	 * Register an user in Odoo with the given {@link OdooUserRole}.
-	 * 
+	 *
 	 * @param jsonObject {@link JsonObject} that represents an user
 	 * @param role       {@link OdooUserRole} to set for the user
 	 * @throws OpenemsNamedException on error
 	 */
 	public void registerUser(JsonObject jsonObject, OdooUserRole role) throws OpenemsNamedException {
-		Optional optEmail = JsonUtils.getAsOptionalString(jsonObject, "email");
-		if (!optEmail.isPresent()) {
+		var emailOpt = JsonUtils.getAsOptionalString(jsonObject, "email");
+		if (!emailOpt.isPresent()) {
 			throw new OpenemsException("No email specified");
 		}
-		String email = optEmail.get();
+		var email = emailOpt.get();
 
 		int[] userFound = OdooUtils.search(this.credentials, Field.User.ODOO_MODEL, //
 				new Domain(Field.User.LOGIN, "=", email));
@@ -715,7 +714,7 @@ public void registerUser(JsonObject jsonObject, OdooUserRole role) throws Openem
 
 	/**
 	 * Call Odoo api to send registration mail via Odoo.
-	 * 
+	 *
 	 * @param odooUserId Odoo user id to send the mail
 	 * @throws OpenemsNamedException error
 	 */
@@ -725,7 +724,7 @@ private void sendRegistrationMail(int odooUserId) throws OpenemsNamedException {
 
 	/**
 	 * Call Odoo api to send registration mail via Odoo.
-	 * 
+	 *
 	 * @param odooUserId Odoo user id to send the mail
 	 * @param password   password for the user
 	 * @throws OpenemsNamedException error
@@ -742,7 +741,7 @@ private void sendRegistrationMail(int odooUserId, String password) throws Openem
 
 	/**
 	 * Update language for the given user.
-	 * 
+	 *
 	 * @param user     {@link MyUser} the current user
 	 * @param language to set
 	 * @throws OpenemsException on error
@@ -750,7 +749,7 @@ private void sendRegistrationMail(int odooUserId, String password) throws Openem
 	public void updateUserLanguage(MyUser user, Language language) throws OpenemsException {
 		try {
 			OdooUtils.write(this.credentials, Field.User.ODOO_MODEL, new Integer[] { user.getOdooId() }, //
-					new FieldValue(Field.User.OPENEMS_LANGUAGE, language.name()));
+					new FieldValue<>(Field.User.OPENEMS_LANGUAGE, language.name()));
 		} catch (OpenemsNamedException ex) {
 			throw new OpenemsException("Unable to set language [" + language.name() + "] for current user", ex);
 		}
diff --git a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/odoo/OdooUserRole.java b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/odoo/OdooUserRole.java
index dc683d84f1c..d1fb5dcd359 100644
--- a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/odoo/OdooUserRole.java
+++ b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/odoo/OdooUserRole.java
@@ -23,7 +23,7 @@ public enum OdooUserRole {
 
 	/**
 	 * Get the Odoo role.
-	 * 
+	 *
 	 * @return Odoo role
 	 */
 	public String getOdooRole() {
@@ -32,7 +32,7 @@ public String getOdooRole() {
 
 	/**
 	 * Get the specified Odoo groups for the role.
-	 * 
+	 *
 	 * @return Groups for an Odoo role
 	 */
 	public OdooUserGroup[] getOdooGroups() {
@@ -41,7 +41,7 @@ public OdooUserGroup[] getOdooGroups() {
 
 	/**
 	 * Transform the specified Odoo group objects to a list of IDs.
-	 * 
+	 *
 	 * @return The Odoo groups as a list of IDs.
 	 */
 	public List toOdooIds() {
@@ -52,7 +52,7 @@ public List toOdooIds() {
 
 	/**
 	 * Get the {@link OdooUserRole} for the given role as {@link String}.
-	 * 
+	 *
 	 * @param role as {@link String} to parse
 	 * @return The Odoo role
 	 * @throws OpenemsException if role does not exist
diff --git a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/odoo/OdooUtils.java b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/odoo/OdooUtils.java
index 0507bd8449d..62e7b451a1a 100644
--- a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/odoo/OdooUtils.java
+++ b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/odoo/OdooUtils.java
@@ -14,7 +14,6 @@
 import java.util.Optional;
 
 import com.google.common.io.ByteStreams;
-import com.google.gson.JsonArray;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
 
@@ -33,11 +32,11 @@ private OdooUtils() {
 
 	public static final String DEFAULT_SERVER_DATE_FORMAT = "yyyy-MM-dd";
 	public static final String DEFAULT_SERVER_TIME_FORMAT = "HH:mm:ss";
-	public static final String DEFAULT_SERVER_DATETIME_FORMAT = DEFAULT_SERVER_DATE_FORMAT + " "
-			+ DEFAULT_SERVER_TIME_FORMAT;
+	public static final String DEFAULT_SERVER_DATETIME_FORMAT = OdooUtils.DEFAULT_SERVER_DATE_FORMAT + " "
+			+ OdooUtils.DEFAULT_SERVER_TIME_FORMAT;
 
 	public static final DateTimeFormatter DATETIME_FORMATTER = DateTimeFormatter
-			.ofPattern(DEFAULT_SERVER_DATETIME_FORMAT);
+			.ofPattern(OdooUtils.DEFAULT_SERVER_DATETIME_FORMAT);
 
 	/**
 	 * Wrapper for the reply of a call to
@@ -55,7 +54,7 @@ public SuccessResponseAndHeaders(JsonElement result, Map> h
 
 	/**
 	 * Sends a JSON-RPC Request to an Odoo server - without Cookie header.
-	 * 
+	 *
 	 * @param url     the URL
 	 * @param request the JSON-RPC Request as {@link JsonObject}
 	 * @return the {@link JsonObject} response and HTTP connection headers on
@@ -69,7 +68,7 @@ public static SuccessResponseAndHeaders sendJsonrpcRequest(String url, JsonObjec
 
 	/**
 	 * Sends a JSON-RPC Request to an Odoo server.
-	 * 
+	 *
 	 * @param url     the URL
 	 * @param cookie  a Cookie string
 	 * @param request the JSON-RPC Request as {@link JsonObject}
@@ -94,39 +93,39 @@ public static SuccessResponseAndHeaders sendJsonrpcRequest(String url, String co
 			}
 
 			// send JSON-RPC request
-			try (OutputStreamWriter out = new OutputStreamWriter(connection.getOutputStream())) {
+			try (var out = new OutputStreamWriter(connection.getOutputStream())) {
 				out.write(request.toString());
 				out.flush();
 			}
 
 			// read JSON-RPC response
-			StringBuilder sb = new StringBuilder();
+			var sb = new StringBuilder();
 			String line = null;
-			try (BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream()))) {
+			try (var br = new BufferedReader(new InputStreamReader(connection.getInputStream()))) {
 				while ((line = br.readLine()) != null) {
 					sb.append(line);
 				}
 			}
-			JsonObject json = JsonUtils.parseToJsonObject(sb.toString());
+			var json = JsonUtils.parseToJsonObject(sb.toString());
 
 			// Handle Success or Error
 			if (json.has("error")) {
-				JsonObject error = JsonUtils.getAsJsonObject(json, "error");
+				var error = JsonUtils.getAsJsonObject(json, "error");
 				// "code":200",
-				int code = JsonUtils.getAsInt(error, "code");
+				var code = JsonUtils.getAsInt(error, "code");
 				// "message":"Odoo Server Error",
-				String message = JsonUtils.getAsString(error, "message");
-				JsonObject data = JsonUtils.getAsJsonObject(error, "data");
+				var message = JsonUtils.getAsString(error, "message");
+				var data = JsonUtils.getAsJsonObject(error, "data");
 				// "name":"odoo.exceptions.AccessDenied",
-				String dataName = JsonUtils.getAsString(data, "name");
+				var dataName = JsonUtils.getAsString(data, "name");
 				// "debug":"Traceback (most recent call last):\n...",
-				String dataDebug = JsonUtils.getAsString(data, "debug");
+				var dataDebug = JsonUtils.getAsString(data, "debug");
 				// "message":"Access denied",
-				String dataMessage = JsonUtils.getAsString(data, "message");
+				var dataMessage = JsonUtils.getAsString(data, "message");
 				// "arguments":["Access denied"],
-				JsonArray dataArguments = JsonUtils.getAsJsonArray(data, "arguments");
+				var dataArguments = JsonUtils.getAsJsonArray(data, "arguments");
 				// "exception_type":"access_denied"
-				String dataExceptionType = JsonUtils.getAsString(data, "exception_type");
+				var dataExceptionType = JsonUtils.getAsString(data, "exception_type");
 				switch (dataName) {
 				case "odoo.exceptions.AccessDenied":
 					throw new OpenemsException(
@@ -134,7 +133,7 @@ public static SuccessResponseAndHeaders sendJsonrpcRequest(String url, String co
 				case "odoo.http.SessionExpiredException":
 					throw new OpenemsException("Session Expired for Request to URL [" + url + "]");
 				default:
-					String exception = "Exception for Request [" + request.toString() + "] to URL [" + url + "]: " //
+					var exception = "Exception for Request [" + request.toString() + "] to URL [" + url + "]: " //
 							+ dataMessage + ";" //
 							+ " Code [" + code + "]" //
 							+ " Code [" + code + "]" //
@@ -167,7 +166,7 @@ public static SuccessResponseAndHeaders sendJsonrpcRequest(String url, String co
 
 	/**
 	 * Sends a request with admin privileges.
-	 * 
+	 *
 	 * @param credentials the Odoo credentials
 	 * @param url         to send the request
 	 * @param request     to send
@@ -175,13 +174,13 @@ public static SuccessResponseAndHeaders sendJsonrpcRequest(String url, String co
 	 */
 	protected static void sendAdminJsonrpcRequest(Credentials credentials, String url, JsonObject request)
 			throws OpenemsNamedException {
-		String session = login(credentials, "admin", credentials.getPassword());
-		sendJsonrpcRequest(credentials.getUrl() + url, "session_id=" + session, request);
+		var session = OdooUtils.login(credentials, "admin", credentials.getPassword());
+		OdooUtils.sendJsonrpcRequest(credentials.getUrl() + url, "session_id=" + session, request);
 	}
 
 	/**
 	 * Authenticates a user using Username and Password.
-	 * 
+	 *
 	 * @param credentials used to get Odoo url
 	 * @param username    the Username
 	 * @param password    the Password
@@ -190,7 +189,7 @@ protected static void sendAdminJsonrpcRequest(Credentials credentials, String ur
 	 */
 	protected static String login(Credentials credentials, String username, String password)
 			throws OpenemsNamedException {
-		JsonObject request = JsonUtils.buildJsonObject() //
+		var request = JsonUtils.buildJsonObject() //
 				.addProperty("jsonrpc", "2.0") //
 				.addProperty("method", "call") //
 				.add("params", JsonUtils.buildJsonObject() //
@@ -201,24 +200,22 @@ protected static String login(Credentials credentials, String username, String p
 				.build();
 		SuccessResponseAndHeaders response = OdooUtils
 				.sendJsonrpcRequest(credentials.getUrl() + "/web/session/authenticate", request);
-		Optional sessionId = OdooHandler.getFieldFromSetCookieHeader(response.headers, "session_id");
-		if (!sessionId.isPresent()) {
+		var sessionIdOpt = OdooHandler.getFieldFromSetCookieHeader(response.headers, "session_id");
+		if (!sessionIdOpt.isPresent()) {
 			throw OpenemsError.COMMON_AUTHENTICATION_FAILED.exception();
-		} else {
-			return sessionId.get();
 		}
+		return sessionIdOpt.get();
 	}
 
 	private static Object executeKw(String url, Object[] params) throws MalformedURLException, XMLRPCException {
-		XMLRPCClient client = new XMLRPCClient(new URL(String.format("%s/xmlrpc/2/object", url)),
-				XMLRPCClient.FLAGS_NIL);
+		var client = new XMLRPCClient(new URL(String.format("%s/xmlrpc/2/object", url)), XMLRPCClient.FLAGS_NIL);
 		client.setTimeout(60 /* seconds */);
 		return client.call("execute_kw", params);
 	}
 
 	/**
 	 * Executes a search on Odoo.
-	 * 
+	 *
 	 * @param credentials the Odoo credentials
 	 * @param model       Odoo model to query (e.g. 'res.partner')
 	 * @param domains     Odoo domain filters
@@ -232,15 +229,15 @@ protected static int[] search(Credentials credentials, String model, Domain... d
 			Domain filter = domains[i];
 			domain[i] = new Object[] { filter.field, filter.operator, filter.value };
 		}
-		Object[] paramsDomain = new Object[] { domain };
+		Object[] paramsDomain = { domain };
 		// Create request params
 		HashMap paramsRules = new HashMap();
 		String action = "search";
-		Object[] params = new Object[] { credentials.getDatabase(), credentials.getUid(), credentials.getPassword(),
-				model, action, paramsDomain, paramsRules };
+		Object[] params = { credentials.getDatabase(), credentials.getUid(), credentials.getPassword(), model, action,
+				paramsDomain, paramsRules };
 		try {
 			// Execute XML request
-			Object[] resultObjs = (Object[]) executeKw(credentials.getUrl(), params);
+			var resultObjs = (Object[]) OdooUtils.executeKw(credentials.getUrl(), params);
 			// Parse results
 			int[] results = new int[resultObjs.length];
 			for (int i = 0; i < resultObjs.length; i++) {
@@ -254,7 +251,7 @@ protected static int[] search(Credentials credentials, String model, Domain... d
 
 	/**
 	 * Reads a record from Odoo.
-	 * 
+	 *
 	 * @param credentials the Odoo credentials
 	 * @param model       Odoo model to query (e.g. 'res.partner')
 	 * @param id          id of model to read
@@ -266,25 +263,25 @@ protected static Map readOne(Credentials credentials, String mod
 			throws OpenemsException {
 		// Create request params
 		// Add ids
-		Object[] paramsIds = new Object[1];
+		var paramsIds = new Object[1];
 		paramsIds[0] = id;
 		// Add fields
-		String[] fieldStrings = new String[fields.length];
+		var fieldStrings = new String[fields.length];
 		for (int i = 0; i < fields.length; i++) {
 			fieldStrings[i] = fields[i].id();
 		}
 		Map paramsFields = new HashMap<>();
 		paramsFields.put("fields", fieldStrings);
 		// Create request params
-		Object[] params = new Object[] { credentials.getDatabase(), credentials.getUid(), credentials.getPassword(),
-				model, "read", paramsIds, paramsFields };
+		Object[] params = { credentials.getDatabase(), credentials.getUid(), credentials.getPassword(), model, "read",
+				paramsIds, paramsFields };
 		try {
 			// Execute XML request
-			Object[] resultObjs = (Object[]) executeKw(credentials.getUrl(), params);
+			var resultObjs = (Object[]) OdooUtils.executeKw(credentials.getUrl(), params);
 			// Parse results
-			for (int i = 0; i < resultObjs.length;) {
+			for (var resultObj : resultObjs) {
 				@SuppressWarnings("unchecked")
-				Map result = (Map) resultObjs[i];
+				var result = (Map) resultObj;
 				return result;
 			}
 			throw new OpenemsException("No matching entry found for id [" + id + "]");
@@ -295,11 +292,11 @@ protected static Map readOne(Credentials credentials, String mod
 
 	/**
 	 * Executes a Search and read on Odoo.
-	 * 
+	 *
 	 * @see Odoo API
 	 *      Integration
-	 * 
+	 *
 	 * @param credentials the Odoo credentials
 	 * @param model       Odoo model to query (e.g. 'res.partner')
 	 * @param domains     Odoo domain filters
@@ -311,26 +308,26 @@ protected static Map readOne(Credentials credentials, String mod
 	protected static Map[] searchAndRead(Credentials credentials, String model, Domain[] domains,
 			Field[] fields) throws OpenemsException {
 		// Add domain filter
-		Object[] domain = new Object[domains.length];
+		var domain = new Object[domains.length];
 		for (int i = 0; i < domains.length; i++) {
 			Domain filter = domains[i];
 			domain[i] = new Object[] { filter.field, filter.operator, filter.value };
 		}
-		Object[] paramsDomain = new Object[] { domain };
+		Object[] paramsDomain = { domain };
 		// Add fields
-		String[] fieldStrings = new String[fields.length];
+		var fieldStrings = new String[fields.length];
 		for (int i = 0; i < fields.length; i++) {
 			fieldStrings[i] = fields[i].id();
 		}
 		Map paramsFields = new HashMap<>();
 		paramsFields.put("fields", fieldStrings);
 		// Create request params
-		String action = "search_read";
-		Object[] params = new Object[] { credentials.getDatabase(), credentials.getUid(), credentials.getPassword(),
-				model, action, paramsDomain, paramsFields };
+		var action = "search_read";
+		Object[] params = { credentials.getDatabase(), credentials.getUid(), credentials.getPassword(), model, action,
+				paramsDomain, paramsFields };
 		try {
 			// Execute XML request
-			executeKw(credentials.getUrl(), params);
+			OdooUtils.executeKw(credentials.getUrl(), params);
 			// Object[] resultObjs = (Object[]) executeKw(url, params);
 			// Parse results
 			// int[] results = new int[resultObjs.length];
@@ -345,7 +342,7 @@ protected static Map[] searchAndRead(Credentials credentials, St
 
 	/**
 	 * Reads multiple records from Odoo.
-	 * 
+	 *
 	 * @param credentials the Odoo credentials
 	 * @param model       Odoo model to query (e.g. 'res.partner')
 	 * @param ids         ids of model to read
@@ -356,7 +353,7 @@ protected static Map[] searchAndRead(Credentials credentials, St
 	protected static Map[] readMany(Credentials credentials, String model, Integer[] ids,
 			Field... fields) throws OpenemsException {
 		// Create request params
-		String action = "read";
+		var action = "read";
 		// Add ids
 		// Object[] paramsIds = Arrays.stream(ids).mapToObj(id -> (Integer)
 		// id).toArray();
@@ -364,24 +361,24 @@ protected static Map[] readMany(Credentials credentials, String
 		// paramsIds[0] = ids[0];
 		// paramsIds[1] = ids[1];
 		// Add fields
-		String[] fieldStrings = new String[fields.length];
+		var fieldStrings = new String[fields.length];
 		for (int i = 0; i < fields.length; i++) {
 			fieldStrings[i] = fields[i].id();
 		}
 		// Map paramsFields = new HashMap<>();
 		// paramsFields.put("fields", fieldStrings);
 		// Create request params
-		Object[] params = new Object[] { credentials.getDatabase(), credentials.getUid(), credentials.getPassword(),
-				model, action, new Object[] { ids, fieldStrings } };
+		Object[] params = { credentials.getDatabase(), credentials.getUid(), credentials.getPassword(), model, action,
+				new Object[] { ids, fieldStrings } };
 		try {
 			// Execute XML request
-			Object[] resultObjs = (Object[]) executeKw(credentials.getUrl(), params);
+			var resultObjs = (Object[]) OdooUtils.executeKw(credentials.getUrl(), params);
 			// Parse results
 			@SuppressWarnings("unchecked")
-			Map[] results = (Map[]) new Map[resultObjs.length];
+			Map[] results = new Map[resultObjs.length];
 			for (int i = 0; i < resultObjs.length; i++) {
 				@SuppressWarnings("unchecked")
-				Map result = (Map) resultObjs[i];
+				var result = (Map) resultObjs[i];
 				results[i] = result;
 			}
 			return results;
@@ -392,7 +389,7 @@ protected static Map[] readMany(Credentials credentials, String
 
 	/**
 	 * Search-Reads multiple records from Odoo.
-	 * 
+	 *
 	 * @param credentials the Odoo credentials
 	 * @param model       Odoo model to query (e.g. 'res.partner')
 	 * @param fields      fields that should be read
@@ -404,32 +401,32 @@ protected static Map[] searchRead(Credentials credentials, Strin
 			Domain... domains) throws OpenemsException {
 		// Create request params
 		// Add domain filter
-		Object[] domain = new Object[domains.length];
+		var domain = new Object[domains.length];
 		for (int i = 0; i < domains.length; i++) {
-			Domain filter = domains[i];
+			var filter = domains[i];
 			domain[i] = new Object[] { filter.field, filter.operator, filter.value };
 		}
-		Object[] paramsDomain = new Object[] { domain };
+		Object[] paramsDomain = { domain };
 		// Add fields
-		String[] fieldStrings = new String[fields.length];
+		var fieldStrings = new String[fields.length];
 		for (int i = 0; i < fields.length; i++) {
 			fieldStrings[i] = fields[i].toString();
 		}
 		Map paramsFields = new HashMap<>();
 		paramsFields.put("fields", fieldStrings);
 		// Create request params
-		Object[] params = new Object[] { credentials.getDatabase(), credentials.getUid(), credentials.getPassword(),
-				model, "search_read", paramsDomain, paramsFields };
+		Object[] params = { credentials.getDatabase(), credentials.getUid(), credentials.getPassword(), model,
+				"search_read", paramsDomain, paramsFields };
 		try {
 			// Execute XML request
-			Object[] resultObjs = (Object[]) executeKw(credentials.getUrl(), params);
+			var resultObjs = (Object[]) OdooUtils.executeKw(credentials.getUrl(), params);
 			// Parse results
 			@SuppressWarnings("unchecked")
-			Map[] results = (Map[]) new Map[resultObjs.length];
+			Map[] results = new Map[resultObjs.length];
 			for (int i = 0; i < resultObjs.length; i++) {
 				@SuppressWarnings("unchecked")
-				Map result = (Map) resultObjs[i];
-				results[0] = result;
+				var result = (Map) resultObjs[i];
+				results[i] = result;
 			}
 			return results;
 		} catch (Throwable e) {
@@ -439,7 +436,7 @@ protected static Map[] searchRead(Credentials credentials, Strin
 
 	/**
 	 * Adds a message in Odoo Chatter ('mail.thread').
-	 * 
+	 *
 	 * @param credentials the Odoo credentials
 	 * @param model       Odoo model (e.g. 'res.partner')
 	 * @param id          id of model
@@ -449,8 +446,8 @@ protected static Map[] searchRead(Credentials credentials, Strin
 	protected static void addChatterMessage(Credentials credentials, String model, int id, String message)
 			throws OpenemsException {
 		// Create request params
-		Object[] params = new Object[] { credentials.getDatabase(), credentials.getUid(), credentials.getPassword(),
-				model, "message_post", new Object[] { id, message } };
+		Object[] params = { credentials.getDatabase(), credentials.getUid(), credentials.getPassword(), model,
+				"message_post", new Object[] { id, message } };
 		try {
 			// Execute XML request
 			Object resultObj = executeKw(credentials.getUrl(), params);
@@ -464,7 +461,7 @@ protected static void addChatterMessage(Credentials credentials, String model, i
 
 	/**
 	 * Create a record in Odoo.
-	 * 
+	 *
 	 * @param credentials the Odoo credentials
 	 * @param model       the Oddo model
 	 * @param fieldValues fields and values that should be written
@@ -478,12 +475,12 @@ protected static int create(Credentials credentials, String model, FieldValue
 			paramsFieldValues.put(fieldValue.getField().id(), fieldValue.getValue());
 		}
 
-		return create(credentials, model, paramsFieldValues);
+		return OdooUtils.create(credentials, model, paramsFieldValues);
 	}
 
 	/**
 	 * Create a record in Odoo.
-	 * 
+	 *
 	 * @param credentials the Odoo credentials
 	 * @param model       the Oddo model
 	 * @param fieldValues fields and values that should be written
@@ -492,10 +489,10 @@ protected static int create(Credentials credentials, String model, FieldValue
 	 */
 	protected static int create(Credentials credentials, String model, Map fieldValues)
 			throws OpenemsException {
-		String action = "create";
+		var action = "create";
 
-		Object[] params = new Object[] { credentials.getDatabase(), credentials.getUid(), credentials.getPassword(),
-				model, action, new Object[] { fieldValues } };
+		Object[] params = { credentials.getDatabase(), credentials.getUid(), credentials.getPassword(), model, action,
+				new Object[] { fieldValues } };
 
 		try {
 			Object resultObj = (Object) executeKw(credentials.getUrl(), params);
@@ -511,7 +508,7 @@ protected static int create(Credentials credentials, String model, Map fieldValues)
 			throws OpenemsException {
 		// Create request params
-		String action = "write";
+		var action = "write";
 
 		// Create request params
-		Object[] params = new Object[] { credentials.getDatabase(), credentials.getUid(), credentials.getPassword(),
-				model, action, new Object[] { ids, fieldValues } };
+		Object[] params = { credentials.getDatabase(), credentials.getUid(), credentials.getPassword(), model, action,
+				new Object[] { ids, fieldValues } };
 		try {
 			// Execute XML request
-			Boolean resultObj = (Boolean) executeKw(credentials.getUrl(), params);
+			var resultObj = (Boolean) OdooUtils.executeKw(credentials.getUrl(), params);
 			if (!resultObj) {
 				throw new OpenemsException("Returned False.");
 			}
@@ -570,45 +567,43 @@ protected static void write(Credentials credentials, String model, Integer[] ids
 
 	/**
 	 * Return the Object type-safe as a String; or otherwise as an empty String.
-	 * 
+	 *
 	 * @param object the value as object
 	 * @return the value as String
 	 */
 	protected static String getAsString(Object object) {
-		if (object != null && object instanceof String) {
+		if (object instanceof String) {
 			return (String) object;
-		} else {
-			return "";
 		}
+		return "";
 	}
 
 	/**
 	 * Return the Object type-safe as a Integer; or otherwise null.
-	 * 
+	 *
 	 * @param object the value as object
 	 * @return the value as Integer
 	 */
 	protected static Integer getAsInteger(Object object) {
-		if (object != null && object instanceof Integer) {
+		if (object instanceof Integer) {
 			return (Integer) object;
-		} else {
-			return null;
 		}
+		return null;
 	}
 
 	/**
 	 * Return the odoo reference id as a {@link Integer}, otherwise empty
 	 * {@link Optional}.
-	 * 
+	 *
 	 * @param object the odoo reference to extract
 	 * @return the odoo reference id or empty {@link Optional}
 	 */
-	protected static Optional getOdooRefernceId(Object object) {
-		if (object != null && object instanceof Object[]) {
-			Object[] odooRefernce = (Object[]) object;
+	protected static Optional getOdooReferenceId(Object object) {
+		if (object instanceof Object[]) {
+			var odooReference = (Object[]) object;
 
-			if (odooRefernce[0] != null && odooRefernce[0] instanceof Integer) {
-				return Optional.of((Integer) odooRefernce[0]);
+			if (odooReference.length > 0 && odooReference[0] instanceof Integer) {
+				return Optional.of((Integer) odooReference[0]);
 			}
 		}
 
@@ -618,7 +613,7 @@ protected static Optional getOdooRefernceId(Object object) {
 	/**
 	 * Returns a Odoo report as a byte array. Search for the given template id in
 	 * combination with the concrete report id.
-	 * 
+	 *
 	 * @param credentials the Odoo credentialss
 	 * @param report      the Odoo template id
 	 * @param id          the Odoo report id
@@ -626,7 +621,7 @@ protected static Optional getOdooRefernceId(Object object) {
 	 * @throws OpenemsNamedException on error
 	 */
 	protected static byte[] getOdooReport(Credentials credentials, String report, int id) throws OpenemsNamedException {
-		String session = login(credentials, "admin", credentials.getPassword());
+		var session = OdooUtils.login(credentials, "admin", credentials.getPassword());
 
 		HttpURLConnection connection = null;
 		try {
diff --git a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/Credentials.java b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/Credentials.java
index fbd179c493b..55edcafa294 100644
--- a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/Credentials.java
+++ b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/Credentials.java
@@ -9,7 +9,7 @@ public class Credentials {
 
 	/**
 	 * Creates {@link Credentials} from a {@link Config}uration.
-	 * 
+	 *
 	 * @param config the configuration
 	 * @return a new {@link Credentials} object
 	 */
diff --git a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/InitializeEdgesWorker.java b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/InitializeEdgesWorker.java
index 8f0690f8fcd..9531bdbc180 100644
--- a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/InitializeEdgesWorker.java
+++ b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/InitializeEdgesWorker.java
@@ -50,7 +50,7 @@ public synchronized void stop() {
 		ThreadPoolUtils.shutdownAndAwaitTermination(this.executor, 5);
 	}
 
-	private Consumer task = (self) -> {
+	private final Consumer task = self -> {
 		/*
 		 * First: mark all Edges as offline
 		 */
@@ -97,7 +97,7 @@ public synchronized void stop() {
 
 	/**
 	 * SELECT {} FROM {edge.device};.
-	 * 
+	 *
 	 * @param connection the {@link Connection}
 	 * @return the {@link PreparedStatement}
 	 * @throws SQLException on error
@@ -111,7 +111,7 @@ private PreparedStatement psQueryAllEdges(Connection connection) throws SQLExcep
 
 	/**
 	 * UPDATE {} SET openems_is_connected = FALSE;.
-	 * 
+	 *
 	 * @param connection the {@link Connection}
 	 * @return the {@link PreparedStatement}
 	 * @throws SQLException on error
diff --git a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/PeriodicWriteWorker.java b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/PeriodicWriteWorker.java
index 5b144eada1b..7c2f23663f3 100644
--- a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/PeriodicWriteWorker.java
+++ b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/PeriodicWriteWorker.java
@@ -1,6 +1,5 @@
 package io.openems.backend.metadata.odoo.postgres;
 
-import java.sql.Connection;
 import java.sql.SQLException;
 import java.time.LocalDateTime;
 import java.time.temporal.ChronoUnit;
@@ -63,7 +62,8 @@ public PeriodicWriteWorker(PostgresHandler parent, HikariDataSource dataSource)
 	public synchronized void start() {
 		this.future = this.executor.scheduleWithFixedDelay(//
 				() -> this.task.accept(this.dataSource), //
-				UPDATE_INTERVAL_IN_SECONDS, UPDATE_INTERVAL_IN_SECONDS, TimeUnit.SECONDS);
+				PeriodicWriteWorker.UPDATE_INTERVAL_IN_SECONDS, PeriodicWriteWorker.UPDATE_INTERVAL_IN_SECONDS,
+				TimeUnit.SECONDS);
 	}
 
 	/**
@@ -78,9 +78,9 @@ public synchronized void stop() {
 		ThreadPoolUtils.shutdownAndAwaitTermination(this.executor, 5);
 	}
 
-	private Consumer task = (dataSource) -> {
+	private final Consumer task = dataSource -> {
 		try {
-			if (DEBUG_MODE) {
+			if (PeriodicWriteWorker.DEBUG_MODE) {
 				this.debugLog();
 			}
 
@@ -101,7 +101,7 @@ public synchronized void stop() {
 
 	/**
 	 * Called on Edge onSetLastMessage event.
-	 * 
+	 *
 	 * @param edge the {@link MyEdge}.
 	 */
 	public void onLastMessage(MyEdge edge) {
@@ -112,7 +112,7 @@ public void onLastMessage(MyEdge edge) {
 
 	/**
 	 * Called on Edge onSetLastUpdate event.
-	 * 
+	 *
 	 * @param edge the {@link MyEdge}.
 	 */
 	public void onLastUpdate(MyEdge edge) {
@@ -123,7 +123,7 @@ public void onLastUpdate(MyEdge edge) {
 
 	/**
 	 * Called on Edge isOnline event.
-	 * 
+	 *
 	 * @param edge the {@link MyEdge}.
 	 */
 	public void isOnline(MyEdge edge) {
@@ -138,7 +138,7 @@ public void isOnline(MyEdge edge) {
 
 	/**
 	 * Called on Edge isOffline event.
-	 * 
+	 *
 	 * @param edge the {@link MyEdge}.
 	 */
 	public void isOffline(MyEdge edge) {
@@ -154,7 +154,7 @@ public void isOffline(MyEdge edge) {
 	private void writeIsOffline(HikariDataSource dataSource) throws SQLException {
 		synchronized (this.isOfflineOdooIds) {
 			if (!this.isOfflineOdooIds.isEmpty()) {
-				StringBuilder sql = new StringBuilder(//
+				var sql = new StringBuilder(//
 						"UPDATE " + EdgeDevice.ODOO_TABLE //
 								+ " SET " + Field.EdgeDevice.OPENEMS_IS_CONNECTED.id() + " = FALSE" //
 								+ " WHERE id IN (");
@@ -172,7 +172,7 @@ private void writeIsOffline(HikariDataSource dataSource) throws SQLException {
 	private void writeIsOnline(HikariDataSource dataSource) throws SQLException {
 		synchronized (this.isOnlineOdooIds) {
 			if (!this.isOnlineOdooIds.isEmpty()) {
-				StringBuilder sql = new StringBuilder(//
+				var sql = new StringBuilder(//
 						"UPDATE " + EdgeDevice.ODOO_TABLE //
 								+ " SET " + Field.EdgeDevice.OPENEMS_IS_CONNECTED.id() + " = TRUE" //
 								+ " WHERE id IN (");
@@ -190,7 +190,7 @@ private void writeIsOnline(HikariDataSource dataSource) throws SQLException {
 	private void writeLastUpdate(HikariDataSource dataSource) throws SQLException {
 		synchronized (this.lastUpdateOdooIds) {
 			if (!this.lastUpdateOdooIds.isEmpty()) {
-				StringBuilder sql = new StringBuilder(//
+				var sql = new StringBuilder(//
 						"UPDATE " + EdgeDevice.ODOO_TABLE //
 								+ " SET " + Field.EdgeDevice.LAST_UPDATE.id() + " = (now() at time zone 'UTC')" //
 								+ " WHERE id IN (");
@@ -208,7 +208,7 @@ private void writeLastUpdate(HikariDataSource dataSource) throws SQLException {
 	private void writeLastMessage(HikariDataSource dataSource) throws SQLException {
 		synchronized (this.lastMessageOdooIds) {
 			if (!this.lastMessageOdooIds.isEmpty()) {
-				StringBuilder sql = new StringBuilder(//
+				var sql = new StringBuilder(//
 						"UPDATE " + EdgeDevice.ODOO_TABLE //
 								+ " SET " + Field.EdgeDevice.LAST_MESSAGE.id() + " = (now() at time zone 'UTC')" //
 								+ " WHERE id IN (");
@@ -224,8 +224,7 @@ private void writeLastMessage(HikariDataSource dataSource) throws SQLException {
 	}
 
 	private void executeSql(HikariDataSource dataSource, String sql) throws SQLException {
-		try (Connection con = dataSource.getConnection(); //
-		) {
+		try (var con = dataSource.getConnection()) {
 			con.createStatement().executeUpdate(sql);
 		}
 	}
@@ -236,7 +235,7 @@ private void executeSql(HikariDataSource dataSource, String sql) throws SQLExcep
 	private LocalDateTime lastExecute = null;
 
 	private synchronized void debugLog() {
-		LocalDateTime now = LocalDateTime.now();
+		var now = LocalDateTime.now();
 		if (this.lastExecute != null) {
 			this.parent.logInfo(this.log, "PeriodicWriteWorker. " //
 					+ "Time since last run: [" + ChronoUnit.SECONDS.between(this.lastExecute, now) + "s]" //
diff --git a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/PgUtils.java b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/PgUtils.java
index bfd223e7602..9eb6f819b49 100644
--- a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/PgUtils.java
+++ b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/PgUtils.java
@@ -12,7 +12,7 @@ public class PgUtils {
 
 	/**
 	 * Adds a message in Odoo Chatter ('mail.thread').
-	 * 
+	 *
 	 * @param credentials the Odoo credentials
 	 * @param model       Odoo model (e.g. 'res.partner')
 	 * @param id          id of model
@@ -25,7 +25,7 @@ protected static void addChatterMessage(Credentials credentials, String model, i
 
 	/**
 	 * Update a record in Odoo.
-	 * 
+	 *
 	 * @param credentials the Odoo credentials
 	 * @param model       the Odoo model
 	 * @param ids         ids of model to update
@@ -38,7 +38,7 @@ public static void write(Credentials credentials, String model, Integer[] ids, F
 
 	/**
 	 * Return the Field of the ResultSet.
-	 * 
+	 *
 	 * @param rs    the ResultSet
 	 * @param field the EdgeDevice
 	 * @return the value as String
@@ -46,17 +46,16 @@ public static void write(Credentials credentials, String model, Integer[] ids, F
 	 * @throws OpenemsException on null
 	 */
 	public static String getAsString(ResultSet rs, Field field) throws SQLException, OpenemsException {
-		String result = rs.getString(field.index());
+		var result = rs.getString(field.index());
 		if (result != null) {
 			return result;
-		} else {
-			throw new OpenemsException("Value of field [" + field.name() + "] is null.");
 		}
+		throw new OpenemsException("Value of field [" + field.name() + "] is null.");
 	}
 
 	/**
 	 * Return the Field of the ResultSet; or default value on error.
-	 * 
+	 *
 	 * @param rs    the ResultSet
 	 * @param field the EdgeDevice field
 	 * @param other the default value
@@ -72,7 +71,7 @@ public static String getAsStringOrElse(ResultSet rs, EdgeDevice field, String ot
 
 	/**
 	 * Return the Field of the ResultSet.
-	 * 
+	 *
 	 * @param rs    the ResultSet
 	 * @param field the EdgeDevice
 	 * @return the value as Integer
@@ -84,7 +83,7 @@ public static int getAsInt(ResultSet rs, EdgeDevice field) throws SQLException {
 
 	/**
 	 * Return the Field of the ResultSet; or default value on error.
-	 * 
+	 *
 	 * @param rs    the ResultSet
 	 * @param field the EdgeDevice field
 	 * @param other the default value
diff --git a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/PostgresHandler.java b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/PostgresHandler.java
index ed0e6e6b417..9009d685459 100644
--- a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/PostgresHandler.java
+++ b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/PostgresHandler.java
@@ -50,7 +50,7 @@ public void deactivate() {
 
 	/**
 	 * Gets the Edge for an API-Key, i.e. authenticates the API-Key.
-	 * 
+	 *
 	 * @param apikey the API-Key
 	 * @return the Edge or Empty
 	 */
@@ -68,7 +68,7 @@ public QueueWriteWorker getQueueWriteWorker() {
 
 	/**
 	 * Creates a {@link HikariDataSource} connection pool.
-	 * 
+	 *
 	 * @param config the configuration
 	 * @return the HikariDataSource
 	 * @throws SQLException on error
@@ -77,7 +77,7 @@ private HikariDataSource getDataSource(Config config) throws SQLException {
 		if (!Driver.isRegistered()) {
 			Driver.register();
 		}
-		PGSimpleDataSource pgds = new PGSimpleDataSource();
+		var pgds = new PGSimpleDataSource();
 		pgds.setServerNames(new String[] { config.pgHost() });
 		pgds.setPortNumbers(new int[] { config.pgPort() });
 		pgds.setDatabaseName(config.database());
@@ -85,7 +85,7 @@ private HikariDataSource getDataSource(Config config) throws SQLException {
 		if (config.pgPassword() != null) {
 			pgds.setPassword(config.pgPassword());
 		}
-		HikariDataSource result = new HikariDataSource();
+		var result = new HikariDataSource();
 		result.setDataSource(pgds);
 		return result;
 	}
diff --git a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/QueueWriteWorker.java b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/QueueWriteWorker.java
index 6f1061010fa..3d3fa505a0f 100644
--- a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/QueueWriteWorker.java
+++ b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/QueueWriteWorker.java
@@ -47,7 +47,7 @@ public QueueWriteWorker(PostgresHandler parent, HikariDataSource dataSource) {
 		this.parent = parent;
 		this.dataSource = dataSource;
 
-		if (DEBUG_MODE) {
+		if (QueueWriteWorker.DEBUG_MODE) {
 			this.debugLogExecutor = Executors.newSingleThreadScheduledExecutor();
 		} else {
 			this.debugLogExecutor = null;
@@ -58,7 +58,7 @@ public QueueWriteWorker(PostgresHandler parent, HikariDataSource dataSource) {
 	 * Starts the {@link QueueWriteWorker}.
 	 */
 	public synchronized void start() {
-		if (DEBUG_MODE) {
+		if (QueueWriteWorker.DEBUG_MODE) {
 			this.initializeDebugLog();
 		}
 	}
@@ -74,16 +74,16 @@ public synchronized void stop() {
 
 	/**
 	 * Adds a {@link DatabaseTask} to the queue.
-	 * 
+	 *
 	 * @param task the {@link DatabaseTask}
 	 */
 	public void addTask(DatabaseTask task) {
-		if (DEBUG_MODE) {
+		if (QueueWriteWorker.DEBUG_MODE) {
 			this.count(task, true);
 		}
 
 		this.executor.execute(() -> {
-			if (DEBUG_MODE) {
+			if (QueueWriteWorker.DEBUG_MODE) {
 				this.count(task, false);
 			}
 
@@ -103,16 +103,16 @@ public void addTask(DatabaseTask task) {
 
 	private void initializeDebugLog() {
 		this.debugLogExecutor.scheduleWithFixedDelay(() -> {
-			long totalTasks = this.executor.getTaskCount();
-			long completedTasks = this.executor.getCompletedTaskCount();
-			int countInsertEdgeConfigUpdateUp = this.countInsertEdgeConfigUpdateUp.get();
-			int countInsertEdgeConfigUpdateDown = this.countInsertEdgeConfigUpdateDown.get();
-			int countInsertOrUpdateDeviceStateUp = this.countInsertOrUpdateDeviceStateUp.get();
-			int countInsertOrUpdateDeviceStateDown = this.countInsertOrUpdateDeviceStateDown.get();
-			int countUpdateEdgeConfigUp = this.countUpdateEdgeConfigUp.get();
-			int countUpdateEdgeConfigDown = this.countUpdateEdgeConfigDown.get();
-			int countUpdateEdgeProducttypeUp = this.countUpdateEdgeProducttypeUp.get();
-			int countUpdateEdgeProducttypeDown = this.countUpdateEdgeProducttypeDown.get();
+			var totalTasks = this.executor.getTaskCount();
+			var completedTasks = this.executor.getCompletedTaskCount();
+			var countInsertEdgeConfigUpdateUp = this.countInsertEdgeConfigUpdateUp.get();
+			var countInsertEdgeConfigUpdateDown = this.countInsertEdgeConfigUpdateDown.get();
+			var countInsertOrUpdateDeviceStateUp = this.countInsertOrUpdateDeviceStateUp.get();
+			var countInsertOrUpdateDeviceStateDown = this.countInsertOrUpdateDeviceStateDown.get();
+			var countUpdateEdgeConfigUp = this.countUpdateEdgeConfigUp.get();
+			var countUpdateEdgeConfigDown = this.countUpdateEdgeConfigDown.get();
+			var countUpdateEdgeProducttypeUp = this.countUpdateEdgeProducttypeUp.get();
+			var countUpdateEdgeProducttypeDown = this.countUpdateEdgeProducttypeDown.get();
 
 			this.parent.logInfo(this.log, "QueueWriteWorker. " //
 					+ "Total tasks [" + totalTasks + "|" + completedTasks + "|" + (totalTasks - completedTasks) + "] " //
diff --git a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/task/DatabaseTask.java b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/task/DatabaseTask.java
index 29907774f9b..621574373df 100644
--- a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/task/DatabaseTask.java
+++ b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/task/DatabaseTask.java
@@ -10,12 +10,12 @@ public abstract class DatabaseTask {
 	/**
 	 * Execute the Task, making sure the Connection handle is released properly on
 	 * exception.
-	 * 
+	 *
 	 * @param dataSource the {@link HikariDataSource}
 	 * @throws SQLException on error
 	 */
 	public void execute(HikariDataSource dataSource) throws SQLException {
-		try (Connection con = dataSource.getConnection()) {
+		try (var con = dataSource.getConnection()) {
 			this._execute(con);
 		}
 	}
diff --git a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/task/InsertEdgeConfigUpdate.java b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/task/InsertEdgeConfigUpdate.java
index b6988c55065..5df6c451d3f 100644
--- a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/task/InsertEdgeConfigUpdate.java
+++ b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/task/InsertEdgeConfigUpdate.java
@@ -26,7 +26,7 @@ public InsertEdgeConfigUpdate(int odooId, EdgeConfigDiff diff) {
 
 	@Override
 	protected void _execute(Connection connection) throws SQLException {
-		PreparedStatement ps = this.psInsertEdgeConfigUpdate(connection);
+		var ps = this.psInsertEdgeConfigUpdate(connection);
 		ps.setTimestamp(1, this.createDate);
 		ps.setInt(2, this.odooId);
 		ps.setString(3, this.teaser);
@@ -37,7 +37,7 @@ protected void _execute(Connection connection) throws SQLException {
 	/**
 	 * UPDATE {} SET openems_config = {}, openems_config_components = {} WHERE id =
 	 * {};.
-	 * 
+	 *
 	 * @param connection the {@link Connection}
 	 * @return the PreparedStatement
 	 * @throws SQLException on error
diff --git a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/task/InsertOrUpdateDeviceStates.java b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/task/InsertOrUpdateDeviceStates.java
index 951b5a024de..0e7983b96fa 100644
--- a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/task/InsertOrUpdateDeviceStates.java
+++ b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/task/InsertOrUpdateDeviceStates.java
@@ -36,7 +36,7 @@ public InsertOrUpdateDeviceStates(int odooId, Timestamp timestamp, List
 	 * Be careful to synchronize access to the resulting PreparedStatement.
-	 * 
+	 *
 	 * @param connection the {@link Connection}
 	 * @return the PreparedStatement
 	 * @throws SQLException on error
diff --git a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/task/UpdateEdgeConfig.java b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/task/UpdateEdgeConfig.java
index 5ea5e46bc34..84daf22d53e 100644
--- a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/task/UpdateEdgeConfig.java
+++ b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/task/UpdateEdgeConfig.java
@@ -26,7 +26,7 @@ public UpdateEdgeConfig(int odooId, EdgeConfig config) {
 
 	@Override
 	protected void _execute(Connection connection) throws SQLException {
-		PreparedStatement ps = this.psUpdateEdgeConfig(connection);
+		var ps = this.psUpdateEdgeConfig(connection);
 		ps.setString(1, this.fullConfig);
 		ps.setString(2, this.componentsConfig);
 		ps.setInt(3, this.odooId);
@@ -36,7 +36,7 @@ protected void _execute(Connection connection) throws SQLException {
 	/**
 	 * UPDATE {} SET openems_config = {}, openems_config_components = {} WHERE id =
 	 * {};.
-	 * 
+	 *
 	 * @param connection the {@link Connection}
 	 * @return the PreparedStatement
 	 * @throws SQLException on error
diff --git a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/task/UpdateEdgeProducttype.java b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/task/UpdateEdgeProducttype.java
index 52f00285088..08390a92d60 100644
--- a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/task/UpdateEdgeProducttype.java
+++ b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/task/UpdateEdgeProducttype.java
@@ -18,7 +18,7 @@ public UpdateEdgeProducttype(int odooId, String producttype) {
 
 	@Override
 	protected void _execute(Connection connection) throws SQLException {
-		PreparedStatement ps = this.psUpdateProductType(connection);
+		var ps = this.psUpdateProductType(connection);
 		ps.setString(1, this.producttype);
 		ps.setInt(2, this.odooId);
 		ps.execute();
@@ -26,7 +26,7 @@ protected void _execute(Connection connection) throws SQLException {
 
 	/**
 	 * UPDATE {} SET version = {} WHERE id = {};.
-	 * 
+	 *
 	 * @param connection the {@link Connection}
 	 * @return the PreparedStatement
 	 * @throws SQLException on error
diff --git a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/task/UpdateEdgeStateActive.java b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/task/UpdateEdgeStateActive.java
index beec53d2307..9eb62671d00 100644
--- a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/task/UpdateEdgeStateActive.java
+++ b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/task/UpdateEdgeStateActive.java
@@ -16,14 +16,14 @@ public UpdateEdgeStateActive(int odooId) {
 
 	@Override
 	protected void _execute(Connection connection) throws SQLException {
-		PreparedStatement ps = this.psUpdateEdgeStateActive(connection);
+		var ps = this.psUpdateEdgeStateActive(connection);
 		ps.setInt(1, this.odooId);
 		ps.execute();
 	}
 
 	/**
 	 * UPDATE {} SET state = 'active' WHERE id = {};.
-	 * 
+	 *
 	 * @param connection the {@link Connection}
 	 * @return the PreparedStatement
 	 * @throws SQLException on error
diff --git a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/task/UpdateSumState.java b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/task/UpdateSumState.java
index f2ef1487f40..a577e966a99 100644
--- a/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/task/UpdateSumState.java
+++ b/io.openems.backend.metadata.odoo/src/io/openems/backend/metadata/odoo/postgres/task/UpdateSumState.java
@@ -19,7 +19,7 @@ public UpdateSumState(int odooId, Level sumState) {
 
 	@Override
 	protected void _execute(Connection connection) throws SQLException {
-		PreparedStatement ps = this.psUpdateSumState(connection);
+		var ps = this.psUpdateSumState(connection);
 		final String sumStateString;
 		if (this.sumState != null) {
 			sumStateString = this.sumState.getName().toLowerCase();
@@ -33,7 +33,7 @@ protected void _execute(Connection connection) throws SQLException {
 
 	/**
 	 * UPDATE {} SET openems_sum_state_level = {} WHERE id = {};.
-	 * 
+	 *
 	 * @param connection the {@link Connection}
 	 * @return the PreparedStatement
 	 * @throws SQLException on error
diff --git a/io.openems.backend.timedata.dummy/src/io/openems/backend/timedata/dummy/TimedataDummy.java b/io.openems.backend.timedata.dummy/src/io/openems/backend/timedata/dummy/TimedataDummy.java
index 3e0d41e2c0e..85f6d788ef9 100644
--- a/io.openems.backend.timedata.dummy/src/io/openems/backend/timedata/dummy/TimedataDummy.java
+++ b/io.openems.backend.timedata.dummy/src/io/openems/backend/timedata/dummy/TimedataDummy.java
@@ -38,22 +38,22 @@ public TimedataDummy() {
 	}
 
 	@Activate
-	void activate(Config config) throws OpenemsException {
+	private void activate(Config config) throws OpenemsException {
 		this.logInfo(this.log, "Activate");
 	}
 
 	@Deactivate
-	void deactivate() {
+	private void deactivate() {
 		this.logInfo(this.log, "Deactivate");
 	}
 
+	@Override
 	public Optional getChannelValue(String edgeId, ChannelAddress channelAddress) {
 		EdgeCache edgeCache = this.edgeCacheMap.get(edgeId);
 		if (edgeCache != null) {
 			return edgeCache.getChannelValue(channelAddress);
-		} else {
-			return Optional.empty();
 		}
+		return Optional.empty();
 	}
 
 	@Override
diff --git a/io.openems.backend.timedata.influx/src/io/openems/backend/timedata/influx/ChannelFormula.java b/io.openems.backend.timedata.influx/src/io/openems/backend/timedata/influx/ChannelFormula.java
index c65be3342fd..808c585368b 100644
--- a/io.openems.backend.timedata.influx/src/io/openems/backend/timedata/influx/ChannelFormula.java
+++ b/io.openems.backend.timedata.influx/src/io/openems/backend/timedata/influx/ChannelFormula.java
@@ -26,6 +26,12 @@ public ChannelFormula(Function function, int staticValue) {
 		this.staticValue = Optional.of(staticValue);
 	}
 
+	/**
+	 * Gets the Channel value.
+	 * 
+	 * @param cache an {@link EdgeCache}
+	 * @return the value
+	 */
 	public int getValue(EdgeCache cache) {
 		if (this.address.isPresent()) {
 			return cache.getChannelValue(this.address.get()).orElse(new JsonPrimitive(0)).getAsInt();
@@ -37,7 +43,7 @@ public int getValue(EdgeCache cache) {
 	}
 
 	public Function getFunction() {
-		return function;
+		return this.function;
 	}
 
 }
diff --git a/io.openems.backend.timedata.influx/src/io/openems/backend/timedata/influx/FieldTypeConflictHandler.java b/io.openems.backend.timedata.influx/src/io/openems/backend/timedata/influx/FieldTypeConflictHandler.java
index d227e5e6dcc..8f2d237524e 100644
--- a/io.openems.backend.timedata.influx/src/io/openems/backend/timedata/influx/FieldTypeConflictHandler.java
+++ b/io.openems.backend.timedata.influx/src/io/openems/backend/timedata/influx/FieldTypeConflictHandler.java
@@ -2,7 +2,6 @@
 
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.function.BiConsumer;
-import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 import org.influxdb.InfluxDBException.FieldTypeConflictException;
@@ -18,7 +17,7 @@
  */
 public class FieldTypeConflictHandler {
 
-	private final static Pattern FIELD_TYPE_CONFLICT_EXCEPTION_PATTERN = Pattern.compile(
+	private static final Pattern FIELD_TYPE_CONFLICT_EXCEPTION_PATTERN = Pattern.compile(
 			"^partial write: field type conflict: input field \"(?.*)\" on measurement \"data\" is type (?\\w+), already exists as type (?\\w+) dropped=\\d+$");
 
 	private final Logger log = LoggerFactory.getLogger(FieldTypeConflictHandler.class);
@@ -32,19 +31,18 @@ public FieldTypeConflictHandler(Influx parent) {
 	/**
 	 * Handles a {@link FieldTypeConflictException}; adds special handling for
 	 * fields that already exist in the database.
-	 * 
-	 * @param failedPoints the failed points
-	 * @param e            the {@link FieldTypeConflictException}
+	 *
+	 * @param e the {@link FieldTypeConflictException}
 	 */
 	public synchronized void handleException(FieldTypeConflictException e) {
-		Matcher matcher = FIELD_TYPE_CONFLICT_EXCEPTION_PATTERN.matcher(e.getMessage());
+		var matcher = FieldTypeConflictHandler.FIELD_TYPE_CONFLICT_EXCEPTION_PATTERN.matcher(e.getMessage());
 		if (!matcher.find()) {
 			this.parent.logWarn(this.log, "Unable to add special field handler for message [" + e.getMessage() + "]");
 			return;
 		}
-		String field = matcher.group("channel");
-		String thisType = matcher.group("thisType");
-		String requiredType = matcher.group("requiredType");
+		var field = matcher.group("channel");
+		var thisType = matcher.group("thisType");
+		var requiredType = matcher.group("requiredType");
 
 		if (this.specialCaseFieldHandlers.containsKey(field)) {
 			// Special handling had already been added.
@@ -55,7 +53,7 @@ public synchronized void handleException(FieldTypeConflictException e) {
 		switch (requiredType) {
 		case "string":
 			handler = (builder, jValue) -> {
-				String value = this.getAsFieldTypeString(jValue);
+				var value = this.getAsFieldTypeString(jValue);
 				if (value != null) {
 					builder.addField(field, value);
 				}
@@ -65,14 +63,14 @@ public synchronized void handleException(FieldTypeConflictException e) {
 		case "integer":
 			handler = (builder, jValue) -> {
 				try {
-					Number value = this.getAsFieldTypeNumber(jValue);
+					var value = this.getAsFieldTypeNumber(jValue);
 					if (value != null) {
 						builder.addField(field, value);
 					}
 				} catch (NumberFormatException e1) {
 					try {
 						// Failed -> try conversion to float and then to int
-						Float value = this.getAsFieldTypeFloat(jValue);
+						var value = this.getAsFieldTypeFloat(jValue);
 						if (value != null) {
 							builder.addField(field, Math.round(value));
 						}
@@ -87,7 +85,7 @@ public synchronized void handleException(FieldTypeConflictException e) {
 		case "float":
 			handler = (builder, jValue) -> {
 				try {
-					Float value = this.getAsFieldTypeFloat(jValue);
+					var value = this.getAsFieldTypeFloat(jValue);
 					if (value != null) {
 						builder.addField(field, value);
 					}
@@ -102,17 +100,15 @@ public synchronized void handleException(FieldTypeConflictException e) {
 		if (handler == null) {
 			this.parent.logWarn(this.log, "Unable to add special field handler for [" + field + "] from [" + thisType
 					+ "] to [" + requiredType + "]");
-			return;
-		} else {
-			this.parent.logInfo(this.log,
-					"Add special field handler for [" + field + "] from [" + thisType + "] to [" + requiredType + "]");
-			this.specialCaseFieldHandlers.put(field, handler);
 		}
+		this.parent.logInfo(this.log,
+				"Add special field handler for [" + field + "] from [" + thisType + "] to [" + requiredType + "]");
+		this.specialCaseFieldHandlers.put(field, handler);
 	}
 
 	/**
-	 * Convert JsonElement to String
-	 * 
+	 * Convert JsonElement to String.
+	 *
 	 * @param jValue the value
 	 * @return the value as String; null if value represents null
 	 */
@@ -124,8 +120,8 @@ private String getAsFieldTypeString(JsonElement jValue) {
 	}
 
 	/**
-	 * Convert JsonElement to Number
-	 * 
+	 * Convert JsonElement to Number.
+	 *
 	 * @param jValue the value
 	 * @return the value as Number; null if value represents null
 	 * @throws NumberFormatException on error
@@ -134,7 +130,7 @@ private Number getAsFieldTypeNumber(JsonElement jValue) throws NumberFormatExcep
 		if (jValue.isJsonNull()) {
 			return null;
 		}
-		String value = jValue.toString().replace("\"", "");
+		var value = jValue.toString().replace("\"", "");
 		if (value.isEmpty()) {
 			return null;
 		}
@@ -142,9 +138,9 @@ private Number getAsFieldTypeNumber(JsonElement jValue) throws NumberFormatExcep
 			return Long.parseLong(value);
 		} catch (NumberFormatException e1) {
 			if (value.equalsIgnoreCase("false")) {
-				return 0l;
+				return 0L;
 			} else if (value.equalsIgnoreCase("true")) {
-				return 1l;
+				return 1L;
 			} else {
 				throw e1;
 			}
@@ -152,8 +148,8 @@ private Number getAsFieldTypeNumber(JsonElement jValue) throws NumberFormatExcep
 	}
 
 	/**
-	 * Convert JsonElement to Float
-	 * 
+	 * Convert JsonElement to Float.
+	 *
 	 * @param jValue the value
 	 * @return the value as Float; null if value represents null
 	 * @throws NumberFormatException on error
@@ -162,7 +158,7 @@ private Float getAsFieldTypeFloat(JsonElement jValue) throws NumberFormatExcepti
 		if (jValue.isJsonNull()) {
 			return null;
 		}
-		String value = jValue.toString().replace("\"", "");
+		var value = jValue.toString().replace("\"", "");
 		if (value.isEmpty()) {
 			return null;
 		}
@@ -171,7 +167,7 @@ private Float getAsFieldTypeFloat(JsonElement jValue) throws NumberFormatExcepti
 
 	/**
 	 * Gets the handler for the given Field.
-	 * 
+	 *
 	 * @param field the Field
 	 * @return the handler or null
 	 */
diff --git a/io.openems.backend.timedata.influx/src/io/openems/backend/timedata/influx/Influx.java b/io.openems.backend.timedata.influx/src/io/openems/backend/timedata/influx/Influx.java
index 281f49a789c..826bed38c64 100644
--- a/io.openems.backend.timedata.influx/src/io/openems/backend/timedata/influx/Influx.java
+++ b/io.openems.backend.timedata.influx/src/io/openems/backend/timedata/influx/Influx.java
@@ -9,8 +9,6 @@
 import java.util.Set;
 import java.util.SortedMap;
 import java.util.concurrent.TimeUnit;
-import java.util.function.BiConsumer;
-import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 import org.influxdb.InfluxDBException.FieldTypeConflictException;
@@ -39,7 +37,6 @@
 import io.openems.common.exceptions.OpenemsError.OpenemsNamedException;
 import io.openems.common.exceptions.OpenemsException;
 import io.openems.common.types.ChannelAddress;
-import io.openems.common.types.EdgeConfig;
 import io.openems.common.types.SemanticVersion;
 import io.openems.common.utils.StringUtils;
 import io.openems.shared.influxdb.InfluxConnector;
@@ -68,17 +65,17 @@ public Influx() {
 	protected volatile Metadata metadata;
 
 	@Activate
-	void activate(Config config) throws OpenemsException {
-		this.logInfo(this.log, "Activate [" + //
-				"url=" + config.url() + //
-				";port=" + config.port() + //
-				";database=" + config.database() + //
-				";retentionPolicy=" + config.retentionPolicy() + //
-				";username=" + config.username() + //
-				";password=" + (config.password() != null ? "ok" : "NOT_SET") + //
-				";measurement=" + config.measurement() + //
-				(config.isReadOnly() ? ";READ_ONLY_MODE" : "") + //
-				"]");
+	private void activate(Config config) throws OpenemsException {
+		this.logInfo(this.log, "Activate [" //
+				+ "url=" + config.url() + ";"//
+				+ "port=" + config.port() + ";" //
+				+ "database=" + config.database() + ";"//
+				+ "retentionPolicy=" + config.retentionPolicy() + ";"//
+				+ "username=" + config.username() + ";"//
+				+ "password=" + (config.password() != null ? "ok" : "NOT_SET") + ";"//
+				+ "measurement=" + config.measurement() //
+				+ (config.isReadOnly() ? ";READ_ONLY_MODE" : "") //
+				+ "]");
 
 		this.influxConnector = new InfluxConnector(config.url(), config.port(), config.username(), config.password(),
 				config.database(), config.retentionPolicy(), config.isReadOnly(), //
@@ -95,7 +92,7 @@ void activate(Config config) throws OpenemsException {
 	}
 
 	@Deactivate
-	void deactivate() {
+	private void deactivate() {
 		this.logInfo(this.log, "Deactivate");
 		if (this.influxConnector != null) {
 			this.influxConnector.deactivate();
@@ -108,7 +105,7 @@ public void write(String edgeId, TreeBasedTable
+	 * e.g. translates "edge0" to "0".
+	 * 
+	 * @param name the edge name
+	 * @return the number
+	 * @throws OpenemsException on error
+	 */
 	public static Integer parseNumberFromName(String name) throws OpenemsException {
 		try {
-			Matcher matcher = NAME_NUMBER_PATTERN.matcher(name);
+			var matcher = Influx.NAME_NUMBER_PATTERN.matcher(name);
 			if (matcher.find()) {
-				String nameNumberString = matcher.group(1);
+				var nameNumberString = matcher.group(1);
 				return Integer.parseInt(nameNumberString);
 			}
 		} catch (NullPointerException e) {
@@ -206,7 +213,6 @@ public SortedMap> queryHis
 	 * @param builder the Influx PointBuilder
 	 * @param field   the field name
 	 * @param element the value
-	 * @return
 	 */
 	private void addValue(Builder builder, String field, JsonElement element) {
 		if (element == null || element.isJsonNull()) {
@@ -218,7 +224,7 @@ private void addValue(Builder builder, String field, JsonElement element) {
 			return;
 		}
 		if (element.isJsonPrimitive()) {
-			JsonPrimitive value = element.getAsJsonPrimitive();
+			var value = element.getAsJsonPrimitive();
 			if (value.isNumber()) {
 				try {
 					builder.addField(field, Long.parseLong(value.toString()));
@@ -243,18 +249,18 @@ private void addValue(Builder builder, String field, JsonElement element) {
 
 	/**
 	 * Handles some special cases for fields.
-	 * 
+	 *
 	 * 

 	 * E.g. to avoid errors like "field type conflict: input field XYZ on
 	 * measurement "data" is type integer, already exists as type string"
-	 * 
+	 *
 	 * @param builder the InfluxDB Builder
 	 * @param field   the fieldName, i.e. the ChannelAddress
 	 * @param value   the value, guaranteed to be not-null and not JsonNull.
 	 * @return true if field was handled; false otherwise
 	 */
 	private boolean specialCaseFieldHandling(Builder builder, String field, JsonElement value) {
-		BiConsumer handler = this.fieldTypeConflictHandler.getHandler(field);
+		var handler = this.fieldTypeConflictHandler.getHandler(field);
 		if (handler == null) {
 			// no special handling exists for this field
 			return false;
@@ -266,35 +272,34 @@ private boolean specialCaseFieldHandling(Builder builder, String field, JsonElem
 
 	@Override
 	public Optional getChannelValue(String edgeId, ChannelAddress address) {
-		EdgeCache cache = this.edgeCacheMap.get(edgeId);
-		if (cache != null) {
-			Optional value = cache.getChannelValue(address);
-			if (value.isPresent()) {
-				return value;
-			}
-			Optional edge = this.metadata.getEdge(edgeId);
-			if (!edge.isPresent()) {
-				return Optional.empty();
-			}
-			if (edge.get().getVersion().isAtLeast(new SemanticVersion(2018, 11, 0))) {
-				return Optional.empty();
-			}
-			// Old version: start compatibility mode
-			ChannelFormula[] compatibility = this.getCompatibilityFormula(edge.get(), address);
-			if (compatibility.length == 0) {
-				return Optional.empty();
-			}
-			// handle compatibility with elder OpenEMS Edge version
-			return this.getCompatibilityChannelValue(compatibility, cache);
-		} else {
+		var cache = this.edgeCacheMap.get(edgeId);
+		if (cache == null) {
+			return Optional.empty();
+		}
+		var value = cache.getChannelValue(address);
+		if (value.isPresent()) {
+			return value;
+		}
+		var edge = this.metadata.getEdge(edgeId);
+		if (!edge.isPresent()) {
+			return Optional.empty();
+		}
+		if (edge.get().getVersion().isAtLeast(new SemanticVersion(2018, 11, 0))) {
+			return Optional.empty();
+		}
+		// Old version: start compatibility mode
+		var compatibility = this.getCompatibilityFormula(edge.get(), address);
+		if (compatibility.length == 0) {
 			return Optional.empty();
 		}
+		// handle compatibility with elder OpenEMS Edge version
+		return this.getCompatibilityChannelValue(compatibility, cache);
 	}
 
 	/**
 	 * Handles compatibility with elder OpenEMS Edge version, e.g. calculate the
 	 * '_sum' Channels.
-	 * 
+	 *
 	 * @param compatibility the formula to calculate the channel value
 	 * @param cache         the EdgeCache
 	 * @return the value as an Optional
@@ -313,14 +318,14 @@ private Optional getCompatibilityChannelValue(ChannelFormula[] comp
 
 	/**
 	 * Gets the formula to calculate a '_sum' Channel value.
-	 * 
+	 *
 	 * @param edge    the Edge
 	 * @param address the ChannelAddress
 	 * @return the formula to calculate the channel value
 	 */
 	@Deprecated
 	private ChannelFormula[] getCompatibilityFormula(Edge edge, ChannelAddress address) {
-		EdgeConfig config = edge.getConfig();
+		var config = edge.getConfig();
 
 		if (address.getComponentId().equals("_sum")) {
 			switch (address.getChannelId()) {
@@ -331,16 +336,15 @@ private ChannelFormula[] getCompatibilityFormula(Edge edge, ChannelAddress addre
 					// take first result
 					return new ChannelFormula[] {
 							new ChannelFormula(Function.PLUS, new ChannelAddress(ids.get(0), "Soc")) };
-				} else {
-					return new ChannelFormula[0];
 				}
+				return new ChannelFormula[0];
 			}
 
 			case "EssActivePower": {
 				List asymmetricIds = config.getComponentsImplementingNature("AsymmetricEssNature");
 				List symmetricIds = config.getComponentsImplementingNature("SymmetricEssNature");
 				symmetricIds.removeAll(asymmetricIds);
-				ChannelFormula[] result = new ChannelFormula[asymmetricIds.size() * 3 + symmetricIds.size()];
+				var result = new ChannelFormula[asymmetricIds.size() * 3 + symmetricIds.size()];
 				int i = 0;
 				for (String id : asymmetricIds) {
 					result[i++] = new ChannelFormula(Function.PLUS, new ChannelAddress(id, "ActivePowerL1"));
@@ -419,7 +423,7 @@ private ChannelFormula[] getCompatibilityFormula(Edge edge, ChannelAddress addre
 				symmetricIds.removeAll(ignoreIds);
 				symmetricIds.removeAll(asymmetricIds);
 
-				ChannelFormula[] result = new ChannelFormula[asymmetricIds.size() * 3 + symmetricIds.size()];
+				var result = new ChannelFormula[asymmetricIds.size() * 3 + symmetricIds.size()];
 				int i = 0;
 				for (String id : asymmetricIds) {
 					result[i++] = new ChannelFormula(Function.PLUS, new ChannelAddress(id, "ActivePowerL1"));
@@ -434,7 +438,7 @@ private ChannelFormula[] getCompatibilityFormula(Edge edge, ChannelAddress addre
 
 			case "ProductionDcActualPower": {
 				List ids = config.getComponentsImplementingNature("ChargerNature");
-				ChannelFormula[] result = new ChannelFormula[ids.size()];
+				var result = new ChannelFormula[ids.size()];
 				for (int i = 0; i < ids.size(); i++) {
 					result[i] = new ChannelFormula(Function.PLUS, new ChannelAddress(ids.get(i), "ActualPower"));
 				}
diff --git a/io.openems.backend.uiwebsocket/src/io/openems/backend/uiwebsocket/impl/OnClose.java b/io.openems.backend.uiwebsocket/src/io/openems/backend/uiwebsocket/impl/OnClose.java
index bacb873c0e7..7bbea9319e3 100644
--- a/io.openems.backend.uiwebsocket/src/io/openems/backend/uiwebsocket/impl/OnClose.java
+++ b/io.openems.backend.uiwebsocket/src/io/openems/backend/uiwebsocket/impl/OnClose.java
@@ -1,12 +1,9 @@
 package io.openems.backend.uiwebsocket.impl;
 
-import java.util.Optional;
-
 import org.java_websocket.WebSocket;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import io.openems.backend.common.metadata.User;
 import io.openems.common.exceptions.OpenemsException;
 
 public class OnClose implements io.openems.common.websocket.OnClose {
@@ -22,9 +19,9 @@ public OnClose(UiWebsocketImpl parent) {
 	public void run(WebSocket ws, int code, String reason, boolean remote) throws OpenemsException {
 		// get current User
 		WsData wsData = ws.getAttachment();
-		Optional userOpt = wsData.getUser(this.parent.metadata);
+		var userOpt = wsData.getUser(this.parent.metadata);
 		if (userOpt.isPresent()) {
-			User user = userOpt.get();
+			var user = userOpt.get();
 			this.parent.logInfo(this.log, "User [" + user.getId() + ":" + user.getName() + "] disconnected.");
 		} else {
 			this.parent.logInfo(this.log, "User [" + wsData.getUserId().orElse("UNKNOWN") + "] disconnected.");
diff --git a/io.openems.backend.uiwebsocket/src/io/openems/backend/uiwebsocket/impl/OnRequest.java b/io.openems.backend.uiwebsocket/src/io/openems/backend/uiwebsocket/impl/OnRequest.java
index 841c55f8375..0bb168fa346 100644
--- a/io.openems.backend.uiwebsocket/src/io/openems/backend/uiwebsocket/impl/OnRequest.java
+++ b/io.openems.backend.uiwebsocket/src/io/openems/backend/uiwebsocket/impl/OnRequest.java
@@ -1,7 +1,5 @@
 package io.openems.backend.uiwebsocket.impl;
 
-import java.util.Map;
-import java.util.Optional;
 import java.util.UUID;
 import java.util.concurrent.CompletableFuture;
 
@@ -9,8 +7,6 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import com.google.gson.JsonObject;
-
 import io.openems.backend.common.jsonrpc.request.AddEdgeToUserRequest;
 import io.openems.backend.common.jsonrpc.request.GetSetupProtocolRequest;
 import io.openems.backend.common.jsonrpc.request.GetUserInformationRequest;
@@ -19,7 +15,6 @@
 import io.openems.backend.common.jsonrpc.request.SubmitSetupProtocolRequest;
 import io.openems.backend.common.jsonrpc.response.AddEdgeToUserResponse;
 import io.openems.backend.common.jsonrpc.response.GetUserInformationResponse;
-import io.openems.backend.common.metadata.Edge;
 import io.openems.backend.common.metadata.User;
 import io.openems.common.exceptions.OpenemsError;
 import io.openems.common.exceptions.OpenemsError.OpenemsNamedException;
@@ -67,7 +62,7 @@ public CompletableFuture run(WebSocket ws, Jso
 		}
 
 		// should be authenticated
-		User user = this.assertUser(wsData, request);
+		var user = this.assertUser(wsData, request);
 
 		switch (request.getMethod()) {
 		case LogoutRequest.METHOD:
@@ -107,7 +102,7 @@ public CompletableFuture run(WebSocket ws, Jso
 
 	/**
 	 * Handles a {@link AuthenticateWithTokenRequest}.
-	 * 
+	 *
 	 * @param wsData  the WebSocket attachment
 	 * @param request the {@link AuthenticateWithTokenRequest}
 	 * @return the JSON-RPC Success Response Future
@@ -121,7 +116,7 @@ private CompletableFuture handleAuthenticateWithTokenReq
 
 	/**
 	 * Handles a {@link AuthenticateWithPasswordRequest}.
-	 * 
+	 *
 	 * @param wsData  the WebSocket attachment
 	 * @param request the {@link AuthenticateWithPasswordRequest}
 	 * @return the JSON-RPC Success Response Future
@@ -132,16 +127,15 @@ private CompletableFuture handleAuthenticateWithPassword
 		if (request.getUsername().isPresent()) {
 			return this.handleAuthentication(wsData, request.getId(),
 					this.parent.metadata.authenticate(request.getUsername().get(), request.getPassword()));
-		} else {
-			return this.handleAuthentication(wsData, request.getId(),
-					this.parent.metadata.authenticate(request.getPassword()));
 		}
+		return this.handleAuthentication(wsData, request.getId(),
+				this.parent.metadata.authenticate(request.getPassword()));
 	}
 
 	/**
 	 * Common handler for {@link AuthenticateWithTokenRequest} and
 	 * {@link AuthenticateWithPasswordRequest}.
-	 * 
+	 *
 	 * @param wsData    the WebSocket attachment
 	 * @param requestId the ID of the original {@link JsonrpcRequest}
 	 * @param user      the authenticated {@link User}
@@ -160,7 +154,7 @@ private CompletableFuture handleAuthentication(WsData ws
 
 	/**
 	 * Handles a {@link RegisterUserRequest}.
-	 * 
+	 *
 	 * @param wsData  the WebSocket attachment
 	 * @param request the {@link RegisterUserRequest}
 	 * @return the JSON-RPC Success Response Future
@@ -175,7 +169,7 @@ private CompletableFuture handleRegisterUserReuqest(WsDa
 
 	/**
 	 * Handles a {@link LogoutRequest}.
-	 * 
+	 *
 	 * @param wsData  the WebSocket attachment
 	 * @param user    the authenticated {@link User}
 	 * @param request the {@link LogoutRequest}
@@ -192,19 +186,19 @@ private CompletableFuture handleLogoutRequest(WsData wsD
 	/**
 	 * Gets the authenticated User or throws an Exception if User is not
 	 * authenticated.
-	 * 
+	 *
 	 * @param wsData  the WebSocket attachment
 	 * @param request the JsonrpcRequest
 	 * @return the {@link User}
 	 * @throws OpenemsNamedException if User is not authenticated
 	 */
 	private User assertUser(WsData wsData, JsonrpcRequest request) throws OpenemsNamedException {
-		Optional userIdOpt = wsData.getUserId();
+		var userIdOpt = wsData.getUserId();
 		if (!userIdOpt.isPresent()) {
 			throw OpenemsError.COMMON_USER_NOT_AUTHENTICATED
 					.exception("User-ID is empty. Ignoring request [" + request.getMethod() + "]");
 		}
-		Optional userOpt = this.parent.metadata.getUser(userIdOpt.get());
+		var userOpt = this.parent.metadata.getUser(userIdOpt.get());
 		if (!userOpt.isPresent()) {
 			throw OpenemsError.COMMON_USER_NOT_AUTHENTICATED.exception("User with ID [" + userIdOpt.get()
 					+ "] is unknown. Ignoring request [" + request.getMethod() + "]");
@@ -214,7 +208,7 @@ private User assertUser(WsData wsData, JsonrpcRequest request) throws OpenemsNam
 
 	/**
 	 * Handles an {@link EdgeRpcRequest}.
-	 * 
+	 *
 	 * @param wsData         the WebSocket attachment
 	 * @param user           the authenticated {@link User}
 	 * @param edgeRpcRequest the {@link EdgeRpcRequest}
@@ -223,8 +217,8 @@ private User assertUser(WsData wsData, JsonrpcRequest request) throws OpenemsNam
 	 */
 	private CompletableFuture handleEdgeRpcRequest(WsData wsData, User user,
 			EdgeRpcRequest edgeRpcRequest) throws OpenemsNamedException {
-		String edgeId = edgeRpcRequest.getEdgeId();
-		JsonrpcRequest request = edgeRpcRequest.getPayload();
+		var edgeId = edgeRpcRequest.getEdgeId();
+		var request = edgeRpcRequest.getPayload();
 		user.assertEdgeRoleIsAtLeast(EdgeRpcRequest.METHOD, edgeId, Role.GUEST);
 
 		CompletableFuture resultFuture;
@@ -246,7 +240,7 @@ private CompletableFuture handleEdgeRpcRequest(WsData wsData, U
 		}
 
 		// Wrap reply in EdgeRpcResponse
-		CompletableFuture result = new CompletableFuture();
+		var result = new CompletableFuture();
 		resultFuture.whenComplete((r, ex) -> {
 			if (ex != null) {
 				result.completeExceptionally(ex);
@@ -262,7 +256,7 @@ private CompletableFuture handleEdgeRpcRequest(WsData wsData, U
 
 	/**
 	 * Handles a {@link SubscribeChannelsRequest}.
-	 * 
+	 *
 	 * @param wsData  the WebSocket attachment
 	 * @param edgeId  the Edge-ID
 	 * @param user    the {@link User} - no specific level required
@@ -273,7 +267,7 @@ private CompletableFuture handleEdgeRpcRequest(WsData wsData, U
 	private CompletableFuture handleSubscribeChannelsRequest(WsData wsData, String edgeId,
 			User user, SubscribeChannelsRequest request) throws OpenemsNamedException {
 		// activate SubscribedChannelsWorker
-		SubscribedChannelsWorker worker = wsData.getSubscribedChannelsWorker(edgeId);
+		var worker = wsData.getSubscribedChannelsWorker(edgeId);
 		worker.handleSubscribeChannelsRequest(user.getRole(edgeId).orElse(Role.GUEST), request);
 
 		// JSON-RPC response
@@ -282,7 +276,7 @@ private CompletableFuture handleSubscribeChannelsRequest
 
 	/**
 	 * Handles a {@link SubscribeSystemLogRequest}.
-	 * 
+	 *
 	 * @param wsData  the WebSocket attachment
 	 * @param edgeId  the Edge-ID
 	 * @param user    the {@link User}
@@ -293,7 +287,7 @@ private CompletableFuture handleSubscribeChannelsRequest
 	private CompletableFuture handleSubscribeSystemLogRequest(WsData wsData, String edgeId,
 			User user, SubscribeSystemLogRequest request) throws OpenemsNamedException {
 		user.assertEdgeRoleIsAtLeast(SubscribeSystemLogRequest.METHOD, edgeId, Role.OWNER);
-		String token = wsData.assertToken();
+		var token = wsData.assertToken();
 
 		// Forward to Edge
 		return this.parent.edgeWebsocket.handleSubscribeSystemLogRequest(edgeId, user, token, request);
@@ -301,7 +295,7 @@ private CompletableFuture handleSubscribeSystemLogReques
 
 	/**
 	 * Handles an {@link AddEdgeToUserRequest}.
-	 * 
+	 *
 	 * @param user    the {@link User}
 	 * @param request the {@link AddEdgeToUserRequest}
 	 * @return the JSON-RPC Success Response Future
@@ -309,14 +303,14 @@ private CompletableFuture handleSubscribeSystemLogReques
 	 */
 	private CompletableFuture handleAddEdgeToUserRequest(User user, AddEdgeToUserRequest request)
 			throws OpenemsNamedException {
-		Edge edge = this.parent.metadata.addEdgeToUser(user, request.getSetupPassword());
+		var edge = this.parent.metadata.addEdgeToUser(user, request.getSetupPassword());
 
 		return CompletableFuture.completedFuture(new AddEdgeToUserResponse(request.getId(), edge));
 	}
 
 	/**
 	 * Handles a {@link GetUserInformationRequest}.
-	 * 
+	 *
 	 * @param user    the {@link User}
 	 * @param request the {@link GetUserInformationRequest}
 	 * @return the JSON-RPC Success Response Future
@@ -324,14 +318,14 @@ private CompletableFuture handleAddEdgeToUserRequest(User
 	 */
 	private CompletableFuture handleGetUserInformationRequest(User user,
 			GetUserInformationRequest request) throws OpenemsNamedException {
-		Map userInformation = this.parent.metadata.getUserInformation(user);
+		var userInformation = this.parent.metadata.getUserInformation(user);
 
 		return CompletableFuture.completedFuture(new GetUserInformationResponse(request.getId(), userInformation));
 	}
 
 	/**
 	 * Handles a {@link SetUserInformationRequest}.
-	 * 
+	 *
 	 * @param user    the {@link User}r
 	 * @param request the {@link SetUserInformationRequest}
 	 * @return the JSON-RPC Success Response Future
@@ -346,7 +340,7 @@ private CompletableFuture handleSetUserInformatio
 
 	/**
 	 * Handles a {@link SubmitSetupProtocolRequest}.
-	 * 
+	 *
 	 * @param user    the {@link User}r
 	 * @param request the {@link SubmitSetupProtocolRequest}
 	 * @return the JSON-RPC Success Response Future
@@ -356,7 +350,7 @@ private CompletableFuture handleSubmitSetupProtoc
 			SubmitSetupProtocolRequest request) throws OpenemsNamedException {
 		int protocolId = this.parent.metadata.submitSetupProtocol(user, request.getJsonObject());
 
-		JsonObject response = JsonUtils.buildJsonObject() //
+		var response = JsonUtils.buildJsonObject() //
 				.addProperty("setupProtocolId", protocolId) //
 				.build();
 
@@ -365,7 +359,7 @@ private CompletableFuture handleSubmitSetupProtoc
 
 	/**
 	 * Handles a {@link GetSetupProtocolRequest}.
-	 * 
+	 *
 	 * @param user    the {@link User}r
 	 * @param request the {@link GetSetupProtocolRequest}
 	 * @return the JSON-RPC Success Response Future
@@ -373,14 +367,14 @@ private CompletableFuture handleSubmitSetupProtoc
 	 */
 	private CompletableFuture handleGetSetupProtocolRequest(User user,
 			GetSetupProtocolRequest request) throws OpenemsNamedException {
-		byte[] protocol = this.parent.metadata.getSetupProtocol(user, request.getSetupProtocolId());
+		var protocol = this.parent.metadata.getSetupProtocol(user, request.getSetupProtocolId());
 
 		return CompletableFuture.completedFuture(new Base64PayloadResponse(request.getId(), protocol));
 	}
 
 	/**
 	 * Handles a {@link UpdateUserLanguageRequest}.
-	 * 
+	 *
 	 * @param user    the {@link User}r
 	 * @param request the {@link UpdateUserLanguageRequest}
 	 * @return the JSON-RPC Success Response Future
diff --git a/io.openems.backend.uiwebsocket/src/io/openems/backend/uiwebsocket/impl/SubscribedChannelsWorker.java b/io.openems.backend.uiwebsocket/src/io/openems/backend/uiwebsocket/impl/SubscribedChannelsWorker.java
index 5775876d818..f796773f6f0 100644
--- a/io.openems.backend.uiwebsocket/src/io/openems/backend/uiwebsocket/impl/SubscribedChannelsWorker.java
+++ b/io.openems.backend.uiwebsocket/src/io/openems/backend/uiwebsocket/impl/SubscribedChannelsWorker.java
@@ -1,7 +1,5 @@
 package io.openems.backend.uiwebsocket.impl;
 
-import java.util.Optional;
-
 import com.google.gson.JsonElement;
 import com.google.gson.JsonNull;
 
@@ -27,8 +25,8 @@ protected JsonElement getChannelValue(ChannelAddress channelAddress) {
 			return JsonNull.INSTANCE;
 		}
 
-		Optional channelCacheValue = this.parent.timeData.getChannelValue(this.edgeId, channelAddress);
-		return channelCacheValue.orElse(JsonNull.INSTANCE);
+		var channelCacheValueOpt = this.parent.timeData.getChannelValue(this.edgeId, channelAddress);
+		return channelCacheValueOpt.orElse(JsonNull.INSTANCE);
 	}
 
 	@Override
diff --git a/io.openems.backend.uiwebsocket/src/io/openems/backend/uiwebsocket/impl/UiWebsocketImpl.java b/io.openems.backend.uiwebsocket/src/io/openems/backend/uiwebsocket/impl/UiWebsocketImpl.java
index 0b495964c45..d2ddc354036 100644
--- a/io.openems.backend.uiwebsocket/src/io/openems/backend/uiwebsocket/impl/UiWebsocketImpl.java
+++ b/io.openems.backend.uiwebsocket/src/io/openems/backend/uiwebsocket/impl/UiWebsocketImpl.java
@@ -1,10 +1,8 @@
 package io.openems.backend.uiwebsocket.impl;
 
 import java.util.ArrayList;
-import java.util.Collection;
 import java.util.Iterator;
 import java.util.List;
-import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
 
 import org.java_websocket.WebSocket;
@@ -20,7 +18,6 @@
 import io.openems.backend.common.edgewebsocket.EdgeWebsocket;
 import io.openems.backend.common.jsonrpc.JsonRpcRequestHandler;
 import io.openems.backend.common.metadata.Metadata;
-import io.openems.backend.common.metadata.User;
 import io.openems.backend.common.timedata.Timedata;
 import io.openems.backend.common.uiwebsocket.UiWebsocket;
 import io.openems.common.exceptions.OpenemsError;
@@ -28,7 +25,6 @@
 import io.openems.common.jsonrpc.base.JsonrpcNotification;
 import io.openems.common.jsonrpc.base.JsonrpcRequest;
 import io.openems.common.jsonrpc.base.JsonrpcResponseSuccess;
-import io.openems.common.session.Role;
 
 @Designate(ocd = Config.class, factory = false)
 @Component(//
@@ -61,24 +57,24 @@ public UiWebsocketImpl() {
 	private Config config;
 
 	private final Runnable startServerWhenMetadataIsInitialized = () -> {
-		this.startServer(config.port(), config.poolSize(), config.debugMode());
+		this.startServer(this.config.port(), this.config.poolSize(), this.config.debugMode());
 	};
 
 	@Activate
-	void activate(Config config) {
+	private void activate(Config config) {
 		this.config = config;
 		this.metadata.addOnIsInitializedListener(this.startServerWhenMetadataIsInitialized);
 	}
 
 	@Deactivate
-	void deactivate() {
+	private void deactivate() {
 		this.metadata.removeOnIsInitializedListener(this.startServerWhenMetadataIsInitialized);
 		this.stopServer();
 	}
 
 	/**
 	 * Create and start new server.
-	 * 
+	 *
 	 * @param port      the port
 	 * @param poolSize  number of threads dedicated to handle the tasks
 	 * @param debugMode activate a regular debug log about the state of the tasks
@@ -109,20 +105,20 @@ protected void logWarn(Logger log, String message) {
 
 	@Override
 	public void send(String token, JsonrpcNotification notification) throws OpenemsNamedException {
-		WsData wsData = this.getWsDataForTokenOrError(token);
+		var wsData = this.getWsDataForTokenOrError(token);
 		wsData.send(notification);
 	}
 
 	@Override
 	public CompletableFuture send(String token, JsonrpcRequest request)
 			throws OpenemsNamedException {
-		WsData wsData = this.getWsDataForTokenOrError(token);
+		var wsData = this.getWsDataForTokenOrError(token);
 		return wsData.send(request);
 	}
 
 	@Override
 	public void sendBroadcast(String edgeId, JsonrpcNotification notification) throws OpenemsNamedException {
-		List wsDatas = this.getWsDatasForEdgeId(edgeId);
+		var wsDatas = this.getWsDatasForEdgeId(edgeId);
 		OpenemsNamedException exception = null;
 		for (WsData wsData : wsDatas) {
 			try {
@@ -138,17 +134,17 @@ public void sendBroadcast(String edgeId, JsonrpcNotification notification) throw
 
 	/**
 	 * Gets the WebSocket connection attachment for a UI token.
-	 * 
+	 *
 	 * @param token the UI token
 	 * @return the WsData
 	 * @throws OpenemsNamedException if there is no connection with this token
 	 */
 	private WsData getWsDataForTokenOrError(String token) throws OpenemsNamedException {
-		Collection connections = this.server.getConnections();
+		var connections = this.server.getConnections();
 		for (Iterator iter = connections.iterator(); iter.hasNext();) {
-			WebSocket websocket = iter.next();
+			var websocket = iter.next();
 			WsData wsData = websocket.getAttachment();
-			Optional thisToken = wsData.getToken();
+			var thisToken = wsData.getToken();
 			if (thisToken.isPresent() && thisToken.get().equals(token)) {
 				return wsData;
 			}
@@ -159,25 +155,25 @@ private WsData getWsDataForTokenOrError(String token) throws OpenemsNamedExcepti
 	/**
 	 * Gets the WebSocket connection attachments of all connections accessing an
 	 * Edge-ID.
-	 * 
+	 *
 	 * @param edgeId the Edge-ID
 	 * @return the WsDatas; empty list if there are none
 	 */
 	private List getWsDatasForEdgeId(String edgeId) {
-		List result = new ArrayList<>();
-		Collection connections = this.server.getConnections();
+		var result = new ArrayList();
+		var connections = this.server.getConnections();
 		for (Iterator iter = connections.iterator(); iter.hasNext();) {
-			WebSocket websocket = iter.next();
+			var websocket = iter.next();
 			WsData wsData = websocket.getAttachment();
 			// get attachment User-ID
-			Optional userIdOpt = wsData.getUserId();
+			var userIdOpt = wsData.getUserId();
 			if (userIdOpt.isPresent()) {
-				String userId = userIdOpt.get();
+				var userId = userIdOpt.get();
 				// get User for User-ID
-				Optional userOpt = this.metadata.getUser(userId);
+				var userOpt = this.metadata.getUser(userId);
 				if (userOpt.isPresent()) {
-					User user = userOpt.get();
-					Optional edgeRoleOpt = user.getRole(edgeId);
+					var user = userOpt.get();
+					var edgeRoleOpt = user.getRole(edgeId);
 					if (edgeRoleOpt.isPresent()) {
 						// User has access to this Edge-ID
 						result.add(wsData);
diff --git a/io.openems.backend.uiwebsocket/src/io/openems/backend/uiwebsocket/impl/WebsocketServer.java b/io.openems.backend.uiwebsocket/src/io/openems/backend/uiwebsocket/impl/WebsocketServer.java
index 0399ee91943..6911661174c 100644
--- a/io.openems.backend.uiwebsocket/src/io/openems/backend/uiwebsocket/impl/WebsocketServer.java
+++ b/io.openems.backend.uiwebsocket/src/io/openems/backend/uiwebsocket/impl/WebsocketServer.java
@@ -49,7 +49,7 @@ protected OnRequest getOnRequest() {
 
 	@Override
 	public OnNotification getOnNotification() {
-		return onNotification;
+		return this.onNotification;
 	}
 
 	@Override
@@ -65,7 +65,7 @@ protected OnClose getOnClose() {
 	@Override
 	protected JsonrpcMessage handleNonJsonrpcMessage(String stringMessage, OpenemsNamedException lastException)
 			throws OpenemsNamedException {
-		log.info("UiWs. handleNonJsonrpcMessage: " + stringMessage);
+		this.log.info("UiWs. handleNonJsonrpcMessage: " + stringMessage);
 		throw new OpenemsException("UiWs. handleNonJsonrpcMessage", lastException);
 	}
 
diff --git a/io.openems.backend.uiwebsocket/src/io/openems/backend/uiwebsocket/impl/WsData.java b/io.openems.backend.uiwebsocket/src/io/openems/backend/uiwebsocket/impl/WsData.java
index 318a3e0370d..649cd089586 100644
--- a/io.openems.backend.uiwebsocket/src/io/openems/backend/uiwebsocket/impl/WsData.java
+++ b/io.openems.backend.uiwebsocket/src/io/openems/backend/uiwebsocket/impl/WsData.java
@@ -51,7 +51,7 @@ public synchronized void unsetUserId() {
 
 	/**
 	 * Gets the authenticated User-ID.
-	 * 
+	 *
 	 * @return the User-ID or Optional.Empty if the User was not authenticated.
 	 */
 	public synchronized Optional getUserId() {
@@ -60,16 +60,15 @@ public synchronized Optional getUserId() {
 
 	/**
 	 * Gets the authenticated User.
-	 * 
+	 *
 	 * @param metadata the Metadata service
 	 * @return the User or Optional.Empty if the User was not authenticated or it is
 	 *         not available from Metadata service
 	 */
 	public synchronized Optional getUser(Metadata metadata) {
-		Optional userId = this.getUserId();
-		if (userId.isPresent()) {
-			Optional user = metadata.getUser(userId.get());
-			return user;
+		var userIdOpt = this.getUserId();
+		if (userIdOpt.isPresent()) {
+			return metadata.getUser(userIdOpt.get());
 		}
 		return Optional.empty();
 	}
@@ -80,7 +79,7 @@ public synchronized void setToken(String token) {
 
 	/**
 	 * Gets the Login-Token.
-	 * 
+	 *
 	 * @return the Login-Token
 	 */
 	public Optional getToken() {
@@ -96,26 +95,26 @@ public void unsetToken() {
 
 	/**
 	 * Gets the token or throws an error if no token was set.
-	 * 
+	 *
 	 * @return the token
 	 * @throws OpenemsNamedException if no token has been set
 	 */
 	public String assertToken() throws OpenemsNamedException {
-		Optional token = this.token;
-		if (token.isPresent()) {
-			return token.get();
+		var tokenOpt = this.token;
+		if (tokenOpt.isPresent()) {
+			return tokenOpt.get();
 		}
 		throw OpenemsError.BACKEND_UI_TOKEN_MISSING.exception();
 	}
 
 	/**
 	 * Gets the SubscribedChannelsWorker to take care of subscribe to CurrentData.
-	 * 
+	 *
 	 * @param edgeId the Edge-ID
 	 * @return the SubscribedChannelsWorker
 	 */
 	public synchronized SubscribedChannelsWorker getSubscribedChannelsWorker(String edgeId) {
-		SubscribedChannelsWorker result = this.subscribedChannelsWorkers.get(edgeId);
+		var result = this.subscribedChannelsWorkers.get(edgeId);
 		if (result == null) {
 			result = new SubscribedChannelsWorker(this.parent.parent, edgeId, this);
 			this.subscribedChannelsWorkers.put(edgeId, result);