Tests has been added

README.md

@@ -530,7 +530,7 @@ CONFIG OPTIONS
 	    retrofit - HTTP client: OkHttp 2.4.0. JSON processing: Gson 2.3.1 (Retrofit 1.9.0)
         retrofit2 - HTTP client: OkHttp 2.5.0. JSON processing: Gson 2.4 (Retrofit 2.0.0-beta2)
         google-api-client - HTTP client: google-api-client 1.23.0. JSON processing: Jackson 2.8.9
-        rest-assured", "HTTP client: rest-assured : 3.0.6. JSON processing: JSON processing: Gson 2.6.1
+        rest-assured - HTTP client: rest-assured : 3.0.6. JSON processing: Gson 2.6.1. Only for Java8 
 ```
 
 Your config file for Java can look like

modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/JavaClientCodegen.java

@@ -84,7 +84,7 @@ public JavaClientCodegen() {
         supportedLibraries.put("resteasy", "HTTP client: Resteasy client 3.1.3.Final. JSON processing: Jackson 2.8.9");
         supportedLibraries.put("vertx", "HTTP client: VertX client 3.2.4. JSON processing: Jackson 2.8.9");
         supportedLibraries.put("google-api-client", "HTTP client: Google API client 1.23.0. JSON processing: Jackson 2.8.9");
-        supportedLibraries.put("rest-assured", "HTTP client: rest-assured : 3.0.6. JSON processing: JSON processing: Gson 2.6.1");
+        supportedLibraries.put("rest-assured", "HTTP client: rest-assured : 3.0.6. JSON processing: Gson 2.6.1. Only for Java8");
 
         CliOption libraryOption = new CliOption(CodegenConstants.LIBRARY, "library template (sub-template) to use");
         libraryOption.setEnum(supportedLibraries);
@@ -250,9 +250,11 @@ public void processOpts() {
             additionalProperties.put("jackson", "true");
 
         } else if (REST_ASSURED.equals(getLibrary()))  {
-            additionalProperties.put("java8", "true");
             additionalProperties.put("gson", "true");
             apiTemplateFiles.put("api.mustache", ".java");
+            supportingFiles.add(new SupportingFile("ResponseSpecBuilders.mustache", invokerFolder, "ResponseSpecBuilders.java"));
+            supportingFiles.add(new SupportingFile("JSON.mustache", invokerFolder, "JSON.java"));
+            supportingFiles.add(new SupportingFile("GsonObjectMapper.mustache", invokerFolder, "GsonObjectMapper.java"));
         } else {
             LOGGER.error("Unknown library option (-l/--library): " + getLibrary());
         }

modules/swagger-codegen/src/main/resources/Java/libraries/rest-assured/ApiClient.mustache

@@ -1,3 +1,5 @@
+{{>licenseInfo}}
+
 package {{invokerPackage}};
 
 import {{apiPackage}}.*;

modules/swagger-codegen/src/main/resources/Java/libraries/rest-assured/GsonObjectMapper.mustache

@@ -0,0 +1,27 @@
+{{>licenseInfo}}
+
+package {{invokerPackage}};
+
+import io.restassured.mapper.ObjectMapper;
+import io.restassured.mapper.ObjectMapperDeserializationContext;
+import io.restassured.mapper.ObjectMapperSerializationContext;
+
+public class GsonObjectMapper implements ObjectMapper {
+
+    private GsonObjectMapper() {
+    }
+
+    public static GsonObjectMapper gson() {
+        return new GsonObjectMapper();
+    }
+
+    @Override
+    public Object deserialize(ObjectMapperDeserializationContext context) {
+        return new JSON().deserialize(context.getDataToDeserialize().asString(), context.getType());
+    }
+
+    @Override
+    public Object serialize(ObjectMapperSerializationContext context) {
+        return new JSON().serialize(context.getObjectToSerialize());
+    }
+}