[Java][Jersey2] Fix generated Jersey 2 ApiClient to be thread-safe

src/main/java/io/swagger/codegen/v3/generators/java/JavaClientCodegen.java

@@ -235,7 +235,11 @@ public void processOpts() {
             if ("retrofit2".equals(getLibrary()) && !usePlayWS) {
                 supportingFiles.add(new SupportingFile("JSON.mustache", invokerFolder, "JSON.java"));
             }
-        } else if ("jersey2".equals(getLibrary()) || "resteasy".equals(getLibrary()))  {
+        } else if ("jersey2".equals(getLibrary()))  {
+            supportingFiles.add(new SupportingFile("JSON.mustache", invokerFolder, "JSON.java"));
+            supportingFiles.add(new SupportingFile("ApiResponse.mustache", invokerFolder, "ApiResponse.java"));
+            additionalProperties.put("jackson", "true");
+        } else if ("resteasy".equals(getLibrary()))  {
             supportingFiles.add(new SupportingFile("JSON.mustache", invokerFolder, "JSON.java"));
             additionalProperties.put("jackson", "true");
         } else if("jersey1".equals(getLibrary())) {

src/main/resources/handlebars/Java/libraries/jersey2/ApiClient.mustache

@@ -71,9 +71,6 @@ public class ApiClient {
 
   protected Map<String, Authentication> authentications;
 
-  protected int statusCode;
-  protected Map<String, List<String>> responseHeaders;
-
   protected DateFormat dateFormat;
 
   public ApiClient() {
@@ -121,22 +118,6 @@ public class ApiClient {
     return this;
   }
 
-  /**
-   * Gets the status code of the previous request
-   * @return Status code
-   */
-  public int getStatusCode() {
-    return statusCode;
-  }
-
-  /**
-   * Gets the response headers of the previous request
-   * @return Response headers
-   */
-  public Map<String, List<String>> getResponseHeaders() {
-    return responseHeaders;
-  }
-
   /**
    * Get authentications (key: authentication name, value: authentication).
    * @return Map of authentication object
@@ -673,7 +654,7 @@ public class ApiClient {
    * @return The response body in type of string
    * @throws ApiException API exception
    */
-  public <T> T invokeAPI(String path, String method, List<Pair> queryParams, Object body, Map<String, String> headerParams, Map<String, Object> formParams, String accept, String contentType, String[] authNames, GenericType<T> returnType) throws ApiException {
+  public <T> ApiResponse<T> invokeAPI(String path, String method, List<Pair> queryParams, Object body, Map<String, String> headerParams, Map<String, Object> formParams, String accept, String contentType, String[] authNames, GenericType<T> returnType) throws ApiException {
     updateParamsForAuth(authNames, queryParams, headerParams);
 
     // Not using `.target(this.basePath).path(path)` below,
@@ -689,7 +670,7 @@ public class ApiClient {
     }
 
     Invocation.Builder invocationBuilder = target.request();
-    
+
     if (accept != null) {
     	invocationBuilder = invocationBuilder.accept(accept);
     }
@@ -732,16 +713,16 @@ public class ApiClient {
         throw new ApiException(500, "unknown method type " + method);
       }
 
-      statusCode = response.getStatusInfo().getStatusCode();
-      responseHeaders = buildResponseHeaders(response);
+      final int statusCode = response.getStatusInfo().getStatusCode();
+      final Map<String, List<String>> responseHeaders = buildResponseHeaders(response);
 
       if (response.getStatus() == Status.NO_CONTENT.getStatusCode()) {
-        return null;
+        return new ApiResponse<>(statusCode, responseHeaders);
       } else if (response.getStatusInfo().getFamily() == Status.Family.SUCCESSFUL) {
         if (returnType == null)
-          return null;
+          return new ApiResponse<>(statusCode, responseHeaders);
         else
-          return deserialize(response, returnType);
+          return new ApiResponse<>(statusCode, responseHeaders, deserialize(response, returnType));
       } else {
         String message = "error";
         String respBody = null;
@@ -812,6 +793,8 @@ public class ApiClient {
    * Update query and header parameters based on authentication settings.
    *
    * @param authNames The authentications to apply
+   * @param queryParams The query parameters
+   * @param headerParams The header parameters
    */
   protected void updateParamsForAuth(String[] authNames, List<Pair> queryParams, Map<String, String> headerParams) {
     for (String authName : authNames) {

src/main/resources/handlebars/Java/libraries/jersey2/ApiResponse.mustache

@@ -0,0 +1,48 @@
+{{>licenseInfo}}
+
+package {{invokerPackage}};
+
+import java.util.List;
+import java.util.Map;
+
+/**
+ * API response returned by API call.
+ *
+ * @param <T> The type of data that is deserialized from response body
+ */
+public class ApiResponse<T> {
+    private final int statusCode;
+    private final Map<String, List<String>> headers;
+    private final T data;
+
+    /**
+     * @param statusCode The status code of HTTP response
+     * @param headers The headers of HTTP response
+     */
+    public ApiResponse(int statusCode, Map<String, List<String>> headers) {
+        this(statusCode, headers, null);
+    }
+
+    /**
+     * @param statusCode The status code of HTTP response
+     * @param headers The headers of HTTP response
+     * @param data The object deserialized from response bod
+     */
+    public ApiResponse(int statusCode, Map<String, List<String>> headers, T data) {
+        this.statusCode = statusCode;
+        this.headers = headers;
+        this.data = data;
+    }
+
+    public int getStatusCode() {
+        return statusCode;
+    }
+
+    public Map<String, List<String>> getHeaders() {
+        return headers;
+    }
+
+    public T getData() {
+        return data;
+    }
+}

src/main/resources/handlebars/Java/libraries/jersey2/api.mustache

@@ -2,6 +2,7 @@ package {{package}};
 
 import {{invokerPackage}}.ApiException;
 import {{invokerPackage}}.ApiClient;
+import {{invokerPackage}}.ApiResponse;
 import {{invokerPackage}}.Configuration;
 import {{invokerPackage}}.Pair;
 
@@ -62,6 +63,35 @@ public class {{classname}} {
   @Deprecated
   {{/isDeprecated}}
   public {{#returnType}}{{{returnType}}} {{/returnType}}{{^returnType}}void {{/returnType}}{{operationId}}({{#parameters}}{{{dataType}}} {{paramName}}{{#has this 'more'}}, {{/has}}{{/parameters}}) throws ApiException {
+    {{#returnType}}
+    return {{operationId}}WithHttpInfo({{#allParams}}{{paramName}}{{#hasMore}}, {{/hasMore}}{{/allParams}}).getData();
+    {{/returnType}}{{^returnType}}
+    {{operationId}}WithHttpInfo({{#allParams}}{{paramName}}{{#hasMore}}, {{/hasMore}}{{/allParams}});
+    {{/returnType}}
+  }
+
+  /**
+   * {{summary}}
+   * {{notes}}
+   {{#allParams}}
+   * @param {{paramName}} {{description}}{{#required}} (required){{/required}}{{^required}} (optional{{#defaultValue}}, default to {{{.}}}{{/defaultValue}}){{/required}}
+   {{/allParams}}
+   {{#returnType}}
+   * @return ApiResponse<{{#returnType}}{{returnType}}{{/returnType}}{{^returnType}}Void{{/returnType}}>
+   {{/returnType}}
+   * @throws ApiException if fails to make API call
+   {{#isDeprecated}}
+   * @deprecated
+   {{/isDeprecated}}
+   {{#externalDocs}}
+   * {{description}}
+   * @see <a href="{{url}}">{{summary}} Documentation</a>
+   {{/externalDocs}}
+   */
+  {{#isDeprecated}}
+  @Deprecated
+  {{/isDeprecated}}
+  public ApiResponse<{{#returnType}}{{{returnType}}}{{/returnType}}{{^returnType}}Void{{/returnType}}> {{operationId}}WithHttpInfo({{#allParams}}{{{dataType}}} {{paramName}}{{#hasMore}}, {{/hasMore}}{{/allParams}}) throws ApiException {
     Object {{localVariablePrefix}}localVarPostBody = {{#bodyParam}}{{paramName}}{{/bodyParam}}{{^bodyParam}}null{{/bodyParam}};
     {{#parameters}}
     {{#required}}
@@ -110,7 +140,7 @@ public class {{classname}} {
     GenericType<{{{returnType}}}> {{localVariablePrefix}}localVarReturnType = new GenericType<{{{returnType}}}>() {};
     return {{localVariablePrefix}}apiClient.invokeAPI({{localVariablePrefix}}localVarPath, "{{httpMethod}}", {{localVariablePrefix}}localVarQueryParams, {{localVariablePrefix}}localVarPostBody, {{localVariablePrefix}}localVarHeaderParams, {{localVariablePrefix}}localVarFormParams, {{localVariablePrefix}}localVarAccept, {{localVariablePrefix}}localVarContentType, {{localVariablePrefix}}localVarAuthNames, {{localVariablePrefix}}localVarReturnType);
     {{/returnType}}{{^returnType}}
-    {{localVariablePrefix}}apiClient.invokeAPI({{localVariablePrefix}}localVarPath, "{{httpMethod}}", {{localVariablePrefix}}localVarQueryParams, {{localVariablePrefix}}localVarPostBody, {{localVariablePrefix}}localVarHeaderParams, {{localVariablePrefix}}localVarFormParams, {{localVariablePrefix}}localVarAccept, {{localVariablePrefix}}localVarContentType, {{localVariablePrefix}}localVarAuthNames, null);
+    return {{localVariablePrefix}}apiClient.invokeAPI({{localVariablePrefix}}localVarPath, "{{httpMethod}}", {{localVariablePrefix}}localVarQueryParams, {{localVariablePrefix}}localVarPostBody, {{localVariablePrefix}}localVarHeaderParams, {{localVariablePrefix}}localVarFormParams, {{localVariablePrefix}}localVarAccept, {{localVariablePrefix}}localVarContentType, {{localVariablePrefix}}localVarAuthNames, null);
     {{/returnType}}
   }
   {{/contents}}