Code optimization (#3118)

* code optimization
* useless import
* optimization

dubbo-cluster/src/main/java/org/apache/dubbo/rpc/cluster/directory/StaticDirectory.java

@@ -29,7 +29,6 @@
 
 /**
  * StaticDirectory
- *
  */
 public class StaticDirectory<T> extends AbstractDirectory<T> {
     private static final Logger logger = LoggerFactory.getLogger(StaticDirectory.class);
@@ -50,8 +49,9 @@ public StaticDirectory(URL url, List<Invoker<T>> invokers) {
 
     public StaticDirectory(URL url, List<Invoker<T>> invokers, RouterChain<T> routerChain) {
         super(url == null && invokers != null && !invokers.isEmpty() ? invokers.get(0).getUrl() : url, routerChain);
-        if (invokers == null || invokers.isEmpty())
+        if (invokers == null || invokers.isEmpty()) {
             throw new IllegalArgumentException("invokers == null");
+        }
         this.invokers = invokers;
     }
 

dubbo-cluster/src/main/java/org/apache/dubbo/rpc/cluster/router/AbstractRouter.java

@@ -70,6 +70,7 @@ public int compareTo(Router o) {
         return (this.getPriority() >= o.getPriority()) ? 1 : -1;
     }
 
+    @Override
     public int getPriority() {
         return priority;
     }

dubbo-common/src/main/java/org/apache/dubbo/common/logger/Logger.java

@@ -28,144 +28,144 @@ public interface Logger {
      *
      * @param msg log this message
      */
-    public void trace(String msg);
+    void trace(String msg);
 
     /**
      * Logs an error with trace log level.
      *
      * @param e log this cause
      */
-    public void trace(Throwable e);
+    void trace(Throwable e);
 
     /**
      * Logs an error with trace log level.
      *
      * @param msg log this message
      * @param e   log this cause
      */
-    public void trace(String msg, Throwable e);
+    void trace(String msg, Throwable e);
 
     /**
      * Logs a message with debug log level.
      *
      * @param msg log this message
      */
-    public void debug(String msg);
+    void debug(String msg);
 
     /**
      * Logs an error with debug log level.
      *
      * @param e log this cause
      */
-    public void debug(Throwable e);
+    void debug(Throwable e);
 
     /**
      * Logs an error with debug log level.
      *
      * @param msg log this message
      * @param e   log this cause
      */
-    public void debug(String msg, Throwable e);
+    void debug(String msg, Throwable e);
 
     /**
      * Logs a message with info log level.
      *
      * @param msg log this message
      */
-    public void info(String msg);
+    void info(String msg);
 
     /**
      * Logs an error with info log level.
      *
      * @param e log this cause
      */
-    public void info(Throwable e);
+    void info(Throwable e);
 
     /**
      * Logs an error with info log level.
      *
      * @param msg log this message
      * @param e   log this cause
      */
-    public void info(String msg, Throwable e);
+    void info(String msg, Throwable e);
 
     /**
      * Logs a message with warn log level.
      *
      * @param msg log this message
      */
-    public void warn(String msg);
+    void warn(String msg);
 
     /**
      * Logs a message with warn log level.
      *
      * @param e log this message
      */
-    public void warn(Throwable e);
+    void warn(Throwable e);
 
     /**
      * Logs a message with warn log level.
      *
      * @param msg log this message
      * @param e   log this cause
      */
-    public void warn(String msg, Throwable e);
+    void warn(String msg, Throwable e);
 
     /**
      * Logs a message with error log level.
      *
      * @param msg log this message
      */
-    public void error(String msg);
+    void error(String msg);
 
     /**
      * Logs an error with error log level.
      *
      * @param e log this cause
      */
-    public void error(Throwable e);
+    void error(Throwable e);
 
     /**
      * Logs an error with error log level.
      *
      * @param msg log this message
      * @param e   log this cause
      */
-    public void error(String msg, Throwable e);
+    void error(String msg, Throwable e);
 
     /**
      * Is trace logging currently enabled?
      *
      * @return true if trace is enabled
      */
-    public boolean isTraceEnabled();
+    boolean isTraceEnabled();
 
     /**
      * Is debug logging currently enabled?
      *
      * @return true if debug is enabled
      */
-    public boolean isDebugEnabled();
+    boolean isDebugEnabled();
 
     /**
      * Is info logging currently enabled?
      *
      * @return true if info is enabled
      */
-    public boolean isInfoEnabled();
+    boolean isInfoEnabled();
 
     /**
      * Is warn logging currently enabled?
      *
      * @return true if warn is enabled
      */
-    public boolean isWarnEnabled();
+    boolean isWarnEnabled();
 
     /**
      * Is error logging currently enabled?
      *
      * @return true if error is enabled
      */
-    public boolean isErrorEnabled();
+    boolean isErrorEnabled();
 
 }

dubbo-common/src/main/java/org/apache/dubbo/common/utils/NetUtils.java

@@ -16,6 +16,7 @@
  */
 package org.apache.dubbo.common.utils;
 
+import org.apache.dubbo.common.Constants;
 import org.apache.dubbo.common.URL;
 import org.apache.dubbo.common.logger.Logger;
 import org.apache.dubbo.common.logger.LoggerFactory;
@@ -37,8 +38,6 @@
  */
 public class NetUtils {
 
-    public static final String LOCALHOST = "127.0.0.1";
-    public static final String ANYHOST = "0.0.0.0";
     private static final Logger logger = LoggerFactory.getLogger(NetUtils.class);
     private static final int RND_PORT_START = 30000;
 
@@ -109,18 +108,18 @@ public static boolean isValidAddress(String address) {
     public static boolean isLocalHost(String host) {
         return host != null
                 && (LOCAL_IP_PATTERN.matcher(host).matches()
-                || host.equalsIgnoreCase("localhost"));
+                || host.equalsIgnoreCase(Constants.LOCALHOST_KEY));
     }
 
     public static boolean isAnyHost(String host) {
-        return "0.0.0.0".equals(host);
+        return Constants.ANYHOST_VALUE.equals(host);
     }
 
     public static boolean isInvalidLocalHost(String host) {
         return host == null
                 || host.length() == 0
-                || host.equalsIgnoreCase("localhost")
-                || host.equals("0.0.0.0")
+                || host.equalsIgnoreCase(Constants.LOCALHOST_KEY)
+                || host.equals(Constants.ANYHOST_VALUE)
                 || (LOCAL_IP_PATTERN.matcher(host).matches());
     }
 
@@ -139,13 +138,14 @@ static boolean isValidAddress(InetAddress address) {
         }
         String name = address.getHostAddress();
         return (name != null
-                && !ANYHOST.equals(name)
-                && !LOCALHOST.equals(name)
-                && IP_PATTERN.matcher(name).matches());
+                && IP_PATTERN.matcher(name).matches()
+                && !Constants.ANYHOST_VALUE.equals(name)
+                && !Constants.LOCALHOST_VALUE.equals(name));
     }
 
     /**
      * Check if an ipv6 address is reachable.
+     *
      * @param address the given address
      * @return true if it is reachable
      */
@@ -166,12 +166,13 @@ static boolean isValidV6Address(Inet6Address address) {
      * normalize the ipv6 Address, convert scope name to scope id.
      * e.g.
      * convert
-     *   fe80:0:0:0:894:aeec:f37d:23e1%en0
+     * fe80:0:0:0:894:aeec:f37d:23e1%en0
      * to
-     *   fe80:0:0:0:894:aeec:f37d:23e1%5
-     *
+     * fe80:0:0:0:894:aeec:f37d:23e1%5
+     * <p>
      * The %5 after ipv6 address is called scope id.
      * see java doc of {@link Inet6Address} for more details.
+     *
      * @param address the input address
      * @return the normalized address, with scope id converted to int
      */
@@ -191,7 +192,7 @@ static InetAddress normalizeV6Address(Inet6Address address) {
 
     public static String getLocalHost() {
         InetAddress address = getLocalAddress();
-        return address == null ? LOCALHOST : address.getHostAddress();
+        return address == null ? Constants.LOCALHOST_VALUE : address.getHostAddress();
     }
 
     public static String filterLocalHost(String host) {
@@ -236,7 +237,7 @@ private static InetAddress getLocalAddress0() {
             localAddress = InetAddress.getLocalHost();
             if (localAddress instanceof Inet6Address) {
                 Inet6Address address = (Inet6Address) localAddress;
-                if (isValidV6Address(address)){
+                if (isValidV6Address(address)) {
                     return normalizeV6Address(address);
                 }
             } else if (isValidAddress(localAddress)) {
@@ -259,7 +260,7 @@ private static InetAddress getLocalAddress0() {
                             InetAddress address = addresses.nextElement();
                             if (address instanceof Inet6Address) {
                                 Inet6Address v6Address = (Inet6Address) address;
-                                if (isValidV6Address(v6Address)){
+                                if (isValidV6Address(v6Address)) {
                                     return normalizeV6Address(v6Address);
                                 }
                             } else if (isValidAddress(address)) {

dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/AbstractConfig.java

@@ -304,9 +304,9 @@ protected static void checkExtension(Class<?> type, String property, String valu
      * Check whether there is a <code>Extension</code> who's name (property) is <code>value</code> (special treatment is
      * required)
      *
-     * @param type The Extension type
+     * @param type     The Extension type
      * @param property The extension key
-     * @param value The Extension name
+     * @param value    The Extension name
      */
     protected static void checkMultiExtension(Class<?> type, String property, String value) {
         checkMultiName(property, value);
@@ -485,12 +485,7 @@ public Map<String, String> getMetaData() {
         for (Method method : methods) {
             try {
                 String name = method.getName();
-                if ((name.startsWith("get") || name.startsWith("is"))
-                        && !name.equals("get")
-                        && !"getClass".equals(name)
-                        && Modifier.isPublic(method.getModifiers())
-                        && method.getParameterTypes().length == 0
-                        && ClassHelper.isPrimitive(method.getReturnType())) {
+                if (isMetaMethod(method)) {
                     String prop = calculateAttributeFromGetter(name);
                     String key;
                     Parameter parameter = method.getAnnotation(Parameter.class);
@@ -620,4 +615,27 @@ public boolean isValid() {
         return true;
     }
 
+    private boolean isMetaMethod(Method method) {
+        String name = method.getName();
+        if (!(name.startsWith("get") || name.startsWith("is"))) {
+            return false;
+        }
+        if ("get".equals(name)) {
+            return false;
+        }
+        if ("getClass".equals(name)) {
+            return false;
+        }
+        if (!Modifier.isPublic(method.getModifiers())) {
+            return false;
+        }
+        if (method.getParameterTypes().length != 0) {
+            return false;
+        }
+        if (!ClassHelper.isPrimitive(method.getReturnType())) {
+            return false;
+        }
+        return true;
+    }
+
 }

dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ReferenceConfig.java

@@ -72,7 +72,7 @@ public class ReferenceConfig<T> extends AbstractReferenceConfig {
      *
      * <li>when the url is dubbo://224.5.6.7:1234/org.apache.dubbo.config.api.DemoService?application=dubbo-sample, then
      * the protocol is <b>DubboProtocol</b></li>
-     *
+     * <p>
      * Actually，when the {@link ExtensionLoader} init the {@link Protocol} instants,it will automatically wraps two
      * layers, and eventually will get a <b>ProtocolFilterWrapper</b> or <b>ProtocolListenerWrapper</b>
      */
@@ -327,7 +327,7 @@ private T createProxy(Map<String, String> map) {
         }
 
         if (isJvmRefer) {
-            URL url = new URL(Constants.LOCAL_PROTOCOL, NetUtils.LOCALHOST, 0, interfaceClass.getName()).addParameters(map);
+            URL url = new URL(Constants.LOCAL_PROTOCOL, Constants.LOCALHOST_VALUE, 0, interfaceClass.getName()).addParameters(map);
             invoker = refprotocol.refer(interfaceClass, url);
             if (logger.isInfoEnabled()) {
                 logger.info("Using injvm service " + interfaceClass.getName());

dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ServiceConfig.java

@@ -57,7 +57,7 @@
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
 
-import static org.apache.dubbo.common.utils.NetUtils.LOCALHOST;
+import static org.apache.dubbo.common.Constants.LOCALHOST_VALUE;
 import static org.apache.dubbo.common.utils.NetUtils.getAvailablePort;
 import static org.apache.dubbo.common.utils.NetUtils.getLocalHost;
 import static org.apache.dubbo.common.utils.NetUtils.isInvalidLocalHost;
@@ -82,7 +82,7 @@ public class ServiceConfig<T> extends AbstractServiceConfig {
      *
      * <li>when the url is dubbo://224.5.6.7:1234/org.apache.dubbo.config.api.DemoService?application=dubbo-sample, then
      * the protocol is <b>DubboProtocol</b></li>
-     *
+     * <p>
      * Actually，when the {@link ExtensionLoader} init the {@link Protocol} instants,it will automatically wraps two
      * layers, and eventually will get a <b>ProtocolFilterWrapper</b> or <b>ProtocolListenerWrapper</b>
      */
@@ -583,7 +583,7 @@ private void exportLocal(URL url) {
         if (!Constants.LOCAL_PROTOCOL.equalsIgnoreCase(url.getProtocol())) {
             URL local = URL.valueOf(url.toFullString())
                     .setProtocol(Constants.LOCAL_PROTOCOL)
-                    .setHost(LOCALHOST)
+                    .setHost(LOCALHOST_VALUE)
                     .setPort(0);
             Exporter<?> exporter = protocol.export(
                     proxyFactory.getInvoker(ref, (Class) interfaceClass, local));