mutualize jackson and gson models in java clients

See #2182

Author: cbornet

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

@@ -210,6 +210,7 @@ public void processOpts() {
         importMapping.put("ApiModel", "io.swagger.annotations.ApiModel");
         importMapping.put("JsonProperty", "com.fasterxml.jackson.annotation.JsonProperty");
         importMapping.put("JsonValue", "com.fasterxml.jackson.annotation.JsonValue");
+        importMapping.put("SerializedName", "com.google.gson.annotations.SerializedName");
         importMapping.put("Objects", "java.util.Objects");
         importMapping.put("StringUtil", invokerPackage + ".StringUtil");
 

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

@@ -115,18 +115,24 @@ public void processOpts() {
 
         if ("feign".equals(getLibrary())) {
             supportingFiles.add(new SupportingFile("FormAwareEncoder.mustache", invokerFolder, "FormAwareEncoder.java"));
+            additionalProperties.put("jackson", "true");
         } else if ("okhttp-gson".equals(getLibrary())) {
             // the "okhttp-gson" library template requires "ApiCallback.mustache" for async call
             supportingFiles.add(new SupportingFile("ApiCallback.mustache", invokerFolder, "ApiCallback.java"));
             supportingFiles.add(new SupportingFile("ApiResponse.mustache", invokerFolder, "ApiResponse.java"));
             supportingFiles.add(new SupportingFile("JSON.mustache", invokerFolder, "JSON.java"));
             supportingFiles.add(new SupportingFile("ProgressRequestBody.mustache", invokerFolder, "ProgressRequestBody.java"));
             supportingFiles.add(new SupportingFile("ProgressResponseBody.mustache", invokerFolder, "ProgressResponseBody.java"));
+            additionalProperties.put("gson", "true");
         } else if (usesAnyRetrofitLibrary()) {
             supportingFiles.add(new SupportingFile("auth/OAuthOkHttpClient.mustache", authFolder, "OAuthOkHttpClient.java"));
             supportingFiles.add(new SupportingFile("CollectionFormats.mustache", invokerFolder, "CollectionFormats.java"));
+            additionalProperties.put("gson", "true");
         } else if("jersey2".equals(getLibrary())) {
             supportingFiles.add(new SupportingFile("JSON.mustache", invokerFolder, "JSON.java"));
+            additionalProperties.put("jackson", "true");
+        } else if(StringUtils.isEmpty(getLibrary())) {
+            additionalProperties.put("jackson", "true");
         }
     }
 
@@ -171,32 +177,34 @@ public void postProcessModelProperty(CodegenModel model, CodegenProperty propert
         if(!BooleanUtils.toBoolean(model.isEnum)) {
             final String lib = getLibrary();
             //Needed imports for Jackson based libraries
-            if(StringUtils.isEmpty(lib) || "feign".equals(lib) || "jersey2".equals(lib)) {
+            if(additionalProperties.containsKey("jackson")) {
                 model.imports.add("JsonProperty");
 
-                if(BooleanUtils.toBoolean(model.hasEnums)) {
+                /*if(BooleanUtils.toBoolean(model.hasEnums)) {
                     model.imports.add("JsonValue");
-                }
+                }*/
+            }
+            if(additionalProperties.containsKey("gson")) {
+                model.imports.add("SerializedName");
             }
         }
     }
 
     @Override
     public Map<String, Object> postProcessModelsEnum(Map<String, Object> objs) {
         objs = super.postProcessModelsEnum(objs);
-        String lib = getLibrary();
-        //Needed imports for Jackson based libraries
-        if (StringUtils.isEmpty(lib) || "feign".equals(lib) || "jersey2".equals(lib)) {
+        //Needed import for Gson based libraries
+        if (additionalProperties.containsKey("gson")) {
             List<Map<String, String>> imports = (List<Map<String, String>>)objs.get("imports");
             List<Object> models = (List<Object>) objs.get("models");
             for (Object _mo : models) {
                 Map<String, Object> mo = (Map<String, Object>) _mo;
                 CodegenModel cm = (CodegenModel) mo.get("model");
                 // for enum model
                 if (Boolean.TRUE.equals(cm.isEnum) && cm.allowableValues != null) {
-                    cm.imports.add(importMapping.get("JsonValue"));
+                    cm.imports.add(importMapping.get("SerializedName"));
                     Map<String, String> item = new HashMap<String, String>();
-                    item.put("import", importMapping.get("JsonValue"));
+                    item.put("import", importMapping.get("SerializedName"));
                     imports.add(item);
                 }
             }