Simplified Jersey2 java client by letting Jersey do most serialization

and deserialization

modules/swagger-codegen/src/main/resources/Java/libraries/jersey2/ApiClient.mustache

@@ -6,6 +6,7 @@ import javax.ws.rs.client.Entity;
 import javax.ws.rs.client.Invocation;
 import javax.ws.rs.client.WebTarget;
 import javax.ws.rs.core.Form;
+import javax.ws.rs.core.GenericType;
 import javax.ws.rs.core.MediaType;
 import javax.ws.rs.core.Response;
 import javax.ws.rs.core.Response.Status;
@@ -29,13 +30,11 @@ import java.util.TimeZone;
 
 import java.net.URLEncoder;
 
-import java.io.IOException;
 import java.io.File;
 import java.io.UnsupportedEncodingException;
 
 import java.text.DateFormat;
 import java.text.SimpleDateFormat;
-import java.text.ParseException;
 
 import {{invokerPackage}}.auth.Authentication;
 import {{invokerPackage}}.auth.HttpBasicAuth;
@@ -412,18 +411,39 @@ public class ApiClient {
    * Serialize the given Java object into string entity according the given
    * Content-Type (only JSON is supported for now).
    */
-  public Entity<String> serialize(Object obj, String contentType) throws ApiException {
-    if (isJsonMime(contentType)) {
-      return Entity.json(json.serialize(obj));
+  public Entity<?> serialize(Object obj, Map<String, Object> formParams, String contentType) throws ApiException {
+    Entity<?> entity = null;
+    if (contentType.startsWith("multipart/form-data")) {
+      MultiPart multiPart = new MultiPart();
+      for (Entry<String, Object> param: formParams.entrySet()) {
+        if (param.getValue() instanceof File) {
+          File file = (File) param.getValue();
+          FormDataContentDisposition contentDisp = FormDataContentDisposition.name(param.getKey())
+              .fileName(file.getName()).size(file.length()).build();
+          multiPart.bodyPart(new FormDataBodyPart(contentDisp, file, MediaType.APPLICATION_OCTET_STREAM_TYPE));
         } else {
-      throw new ApiException(400, "can not serialize object into Content-Type: " + contentType);
+          FormDataContentDisposition contentDisp = FormDataContentDisposition.name(param.getKey()).build();
+          multiPart.bodyPart(new FormDataBodyPart(contentDisp, parameterToString(param.getValue())));
         }
       }
+      entity = Entity.entity(multiPart, MediaType.MULTIPART_FORM_DATA_TYPE);
+    } else if (contentType.startsWith("application/x-www-form-urlencoded")) {
+      Form form = new Form();
+      for (Entry<String, Object> param: formParams.entrySet()) {
+        form.param(param.getKey(), parameterToString(param.getValue()));
+      }
+      entity = Entity.entity(form, MediaType.APPLICATION_FORM_URLENCODED_TYPE);
+    } else {
+      // We let jersey handle the serialization
+      entity = Entity.entity(obj, contentType);
+    }
+    return entity;
+  }
 
   /**
    * Deserialize response body to Java object according to the Content-Type.
    */
-  public <T> T deserialize(Response response, TypeRef returnType) throws ApiException {
+  public <T> T deserialize(Response response, GenericType<T> returnType) throws ApiException {
     String contentType = null;
     List<Object> contentTypes = response.getHeaders().get("Content-Type");
     if (contentTypes != null && !contentTypes.isEmpty())
@@ -431,24 +451,7 @@ public class ApiClient {
     if (contentType == null)
       throw new ApiException(500, "missing Content-Type in response");
 
-    String body;
-    if (response.hasEntity())
-      body = (String) response.readEntity(String.class);
-    else
-      body = "";
-
-    if (isJsonMime(contentType)) {
-      return json.deserialize(body, returnType);
-    } else if (returnType.getType().equals(String.class)) {
-      // Expecting string, return the raw response body.
-      return (T) body;
-    } else {
-      throw new ApiException(
-        500,
-        "Content type \"" + contentType + "\" is not supported for type: "
-          + returnType.getType()
-      );
-    }
+    return response.readEntity(returnType);
   }
 
   /**
@@ -466,7 +469,7 @@ public class ApiClient {
    * @param returnType The return type into which to deserialize the response
    * @return The response body in type of string
    */
-  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, TypeRef returnType) throws ApiException {
+  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 {
     updateParamsForAuth(authNames, queryParams, headerParams);
 
     WebTarget target = client.target(this.basePath).path(path);
@@ -497,50 +500,16 @@ public class ApiClient {
       }
     }
 
-    Entity<?> formEntity = null;
-
-    if (contentType.startsWith("multipart/form-data")) {
-      MultiPart multiPart = new MultiPart();
-      for (Entry<String, Object> param: formParams.entrySet()) {
-        if (param.getValue() instanceof File) {
-          File file = (File) param.getValue();
-          FormDataContentDisposition contentDisp = FormDataContentDisposition.name(param.getKey())
-              .fileName(file.getName()).size(file.length()).build();
-          multiPart.bodyPart(new FormDataBodyPart(contentDisp, file, MediaType.APPLICATION_OCTET_STREAM_TYPE));
-        } else {
-          FormDataContentDisposition contentDisp = FormDataContentDisposition.name(param.getKey()).build();
-          multiPart.bodyPart(new FormDataBodyPart(contentDisp, parameterToString(param.getValue())));
-        }
-      }
-      formEntity = Entity.entity(multiPart, MediaType.MULTIPART_FORM_DATA_TYPE);
-    } else if (contentType.startsWith("application/x-www-form-urlencoded")) {
-      Form form = new Form();
-      for (Entry<String, Object> param: formParams.entrySet()) {
-        form.param(param.getKey(), parameterToString(param.getValue()));
-      }
-      formEntity = Entity.entity(form, MediaType.APPLICATION_FORM_URLENCODED_TYPE);
-    }
+    Entity<?> entity = serialize(body, formParams, contentType);
 
     Response response = null;
 
     if ("GET".equals(method)) {
       response = invocationBuilder.get();
     } else if ("POST".equals(method)) {
-      if (formEntity != null) {
-        response = invocationBuilder.post(formEntity);
-      } else if (body == null) {
-        response = invocationBuilder.post(null);
-      } else {
-        response = invocationBuilder.post(serialize(body, contentType));
-      }
+      response = invocationBuilder.post(entity);
     } else if ("PUT".equals(method)) {
-      if (formEntity != null) {
-        response = invocationBuilder.put(formEntity);
-      } else if (body == null) {
-        response = invocationBuilder.put(null);
-      } else {
-        response = invocationBuilder.put(serialize(body, contentType));
-      }
+      response = invocationBuilder.put(entity);
     } else if ("DELETE".equals(method)) {
       response = invocationBuilder.delete();
     } else {
@@ -579,6 +548,8 @@ public class ApiClient {
   private void buildClient() {
     final ClientConfig clientConfig = new ClientConfig();
     clientConfig.register(MultiPartFeature.class);
+    clientConfig.register(json);
+    clientConfig.register(org.glassfish.jersey.jackson.JacksonFeature.class);
     if (debugging) {
       clientConfig.register(LoggingFilter.class);
     }

modules/swagger-codegen/src/main/resources/Java/libraries/jersey2/JSON.mustache

@@ -0,0 +1,36 @@
+package {{invokerPackage}};
+
+import com.fasterxml.jackson.annotation.*;
+import com.fasterxml.jackson.databind.*;
+import com.fasterxml.jackson.datatype.joda.*;
+
+import java.text.DateFormat;
+
+import javax.ws.rs.ext.ContextResolver;
+
+{{>generatedAnnotation}}
+public class JSON implements ContextResolver<ObjectMapper> {
+  private ObjectMapper mapper;
+
+  public JSON() {
+    mapper = new ObjectMapper();
+    mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
+    mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+    mapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
+    mapper.enable(SerializationFeature.WRITE_ENUMS_USING_TO_STRING);
+    mapper.enable(DeserializationFeature.READ_ENUMS_USING_TO_STRING);
+    mapper.registerModule(new JodaModule());
+  }
+
+  /**
+   * Set the date format for JSON (de)serialization with Date properties.
+   */
+  public void setDateFormat(DateFormat dateFormat) {
+    mapper.setDateFormat(dateFormat);
+  }
+
+  @Override
+  public ObjectMapper getContext(Class<?> type) {
+    return mapper;
+  }
+}

modules/swagger-codegen/src/main/resources/Java/libraries/jersey2/api.mustache

@@ -4,7 +4,8 @@ import {{invokerPackage}}.ApiException;
 import {{invokerPackage}}.ApiClient;
 import {{invokerPackage}}.Configuration;
 import {{invokerPackage}}.Pair;
-import {{invokerPackage}}.TypeRef;
+
+import javax.ws.rs.core.GenericType;
 
 {{#imports}}import {{import}};
 {{/imports}}
@@ -83,7 +84,7 @@ public class {{classname}} {
     String[] {{localVariablePrefix}}authNames = new String[] { {{#authMethods}}"{{name}}"{{#hasMore}}, {{/hasMore}}{{/authMethods}} };
 
     {{#returnType}}
-    TypeRef {{localVariablePrefix}}returnType = new TypeRef<{{{returnType}}}>() {};
+    GenericType<{{{returnType}}}> {{localVariablePrefix}}returnType = new GenericType<{{{returnType}}}>() {};
     return {{localVariablePrefix}}apiClient.invokeAPI({{localVariablePrefix}}path, "{{httpMethod}}", {{localVariablePrefix}}queryParams, {{localVariablePrefix}}postBody, {{localVariablePrefix}}headerParams, {{localVariablePrefix}}formParams, {{localVariablePrefix}}accept, {{localVariablePrefix}}contentType, {{localVariablePrefix}}authNames, {{localVariablePrefix}}returnType);
     {{/returnType}}{{^returnType}}
     {{localVariablePrefix}}apiClient.invokeAPI({{localVariablePrefix}}path, "{{httpMethod}}", {{localVariablePrefix}}queryParams, {{localVariablePrefix}}postBody, {{localVariablePrefix}}headerParams, {{localVariablePrefix}}formParams, {{localVariablePrefix}}accept, {{localVariablePrefix}}contentType, {{localVariablePrefix}}authNames, null);

modules/swagger-codegen/src/main/resources/Java/libraries/jersey2/pom.mustache

@@ -124,6 +124,11 @@
       <artifactId>jersey-media-multipart</artifactId>
       <version>${jersey-version}</version>
     </dependency>
+    <dependency>
+      <groupId>org.glassfish.jersey.media</groupId>
+      <artifactId>jersey-media-json-jackson</artifactId>
+      <version>2.22.1</version>
+    </dependency>
     
     <!-- JSON processing: jackson -->
     <dependency>