RESTful Java Client with Jersey Client Example

   This Post explains the Jersey client API’s to create RESTful java client  GET, POST and PUT request to Rest API service.

       1. Jersey Client Dependency

 Declare the fallowing dependencies in the pom.xml file.

<dependency>

              <groupId>org.glassfish.jersey.containers</groupId>

              <artifactId>jersey-container-servlet</artifactId>

              <version>2.5.1</version>

       </dependency>

       <dependency>

              <groupId>org.glassfish.jersey.core</groupId>

              <artifactId>jersey-client</artifactId>

              <version>2.5.1</version>

       </dependency>

       <dependency>

              <groupId>com.fasterxml.jackson.jaxrs</groupId>

              <artifactId>jackson-jaxrs-json-provider</artifactId>

              <version>2.2.3</version>

       </dependency>

       <dependency>

              <groupId>com.google.code.gson</groupId>

              <artifactId>gson</artifactId>

              <version>2.3</version>

       </dependency>

2.  GET Request, POST Request, PUT Request

REST Service Example refer before post

package com.sparktheprograms.jersey;

import javax.ws.rs.Consumes;

import javax.ws.rs.GET;

import javax.ws.rs.POST;

import javax.ws.rs.PUT;

import javax.ws.rs.Path;

import javax.ws.rs.Produces;

import javax.ws.rs.core.MediaType;

import javax.ws.rs.core.Response;

@Path("api")

public class JerseyService {

      

       @GET

       @Produces(MediaType.TEXT_PLAIN)

       public String helloMessage() {

              return "Hey, This is Jersey !";

       }

      

       @GET

       @Path("/getMessage")

       @Produces(MediaType.APPLICATION_JSON)

       public Message message() {

              Message message = new Message();

              message.setSite("www.9threes.com");

              message.setMessage("JERSEY Sample Application");

              return message;

       }

      

       @POST

       @Path("/postMessage")

       @Consumes(MediaType.APPLICATION_JSON)

       public Response createMessageJson(Message message) {

              String data = "Message Saved"+message;

              return Response.status(200).entity(data).build();

       }

      

       @PUT

       @Path("/putMessage")

       @Consumes(MediaType.APPLICATION_JSON)

       public Response putMessage(Message msg) {

              String data = "Message Saved"+msg;

              return Response.status(200).entity(data).build();

       }

}

3.  Jersey Client to send GET Request, Post Request and PUT Request to Jersey Service then jersey service returned the Response to Jersey Client.

package com.sparktheprograms.jersey.client;

import javax.ws.rs.client.Client;

import javax.ws.rs.client.ClientBuilder;

import javax.ws.rs.client.Entity;

import javax.ws.rs.client.WebTarget;

import javax.ws.rs.core.GenericType;

import javax.ws.rs.core.MediaType;

import javax.ws.rs.core.Response;

import com.google.gson.Gson;

import com.sparktheprograms.jersey.Message;

public class JerseyClient {

       public static final String baseUri = "http://localhost:8888/JerseySampleApp/rest/api";

       private Client client = null;

       private WebTarget target = null;

      

       public JerseyClient() {

              client = ClientBuilder.newClient();

              target = client.target(baseUri);

       }

      

       public void reloadUri() {

              target = null;

              target = client.target(baseUri);

       }

      

       public void getRequest() {

              target = target.path("/getMessage");

              // GET Request from Jersey Client

              Response response =  target.request(MediaType.APPLICATION_JSON) 

                                   .get(Response.class);                                

              if(response.getStatus() == 200) {

                     Message message = response.readEntity(new GenericType<Message>() {});

                     System.out.println(message.getSite());

              }

       }

      

       public void postRequest() {

              reloadUri();

              String input ="{\"site\":\"www.9threes.com\",\"message\":\"is new domain\"}";

              target = target.path("/postMessage");

              // POST Request from Jersey Client

              Response response = target.request(MediaType.APPLICATION_JSON)

               .post(Entity.entity(input, MediaType.APPLICATION_JSON),Response.class);

             

              System.out.println(response);

              if(response.getStatus() == 200) {

                     System.out.println("post success");

              }

       }

      

       public void postRequestUsingGson() {

              reloadUri();

              target = target.path("/postMessage");

              Gson gson = new Gson();

              Message msg = new Message();

              msg.setSite("9threes");

              msg.setMessage("its a new Blog");

              String input = gson.toJson(msg);

              //POST Request from jersey Client Using GSON

              Response response = target.request(MediaType.APPLICATION_JSON)

               .post(Entity.entity(input, MediaType.APPLICATION_JSON),Response.class);

             

              System.out.println(response);

              if(response.getStatus() == 200) {

                     System.out.println("post request using Json is Success");

              }

       }

      

       public void putRequest() {

              reloadUri();

              target = target.path("putMessage");

              String input ="{\"site\":\"www.9threes.com\",\"message\":\"is new domain\"}";

              

              //PUT Request from Jersey Client Example

              Response response = target.request(MediaType.APPLICATION_JSON)

               .put(Entity.entity(input, MediaType.APPLICATION_JSON),Response.class);

             

              System.out.println(response);

              if(response.getStatus() == 200) {

                     System.out.println("put request using Json is Success");

              }

       }

      

       public static void main(String args[]) throws Exception {

              try {

                     JerseyClient jerseyClient = new JerseyClient();

                     jerseyClient.getRequest();

                     jerseyClient.postRequest();

                     jerseyClient.postRequestUsingGson();

                     jerseyClient.putRequest();

              } catch(Exception e) {

                     System.out.println(e);

              }

       }

}

Output of above Jersey client Example

        In the above Jersey client example example implemented the GET Request , POST Request and PUT  Request Methods. I implemented two types of methods for POST Request above jersey Client Example ,one method is implemented with JSON data and second method is implemented using GSON API for Converting the JAVA POJO object into JSON format for Jersey Service.