This tutorial show you how to use Jersey client APIs to create a RESTful Java client to perform “GET” and “POST” requests to REST service that created in this “Jersey + Json” example.

1. Jersey Client Dependency

To use Jersey client APIs, declares “jersey-client.jar” in your pom.xml file.

File : pom.xml


	<dependency>
		<groupId>com.sun.jersey</groupId>
		<artifactId>jersey-client</artifactId>
		<version>1.8</version>
	</dependency>

2. GET Request

Review last REST service.


@Path("/json/metallica")
public class JSONService {

	@GET
	@Path("/get")
	@Produces(MediaType.APPLICATION_JSON)
	public Track getTrackInJSON() {

		Track track = new Track();
		track.setTitle("Enter Sandman");
		track.setSinger("Metallica");

		return track;

	}
	//...

Jersey client to send a “GET” request and print out the returned json data.


package com.mkyong.client;

import com.sun.jersey.api.client.Client;
import com.sun.jersey.api.client.ClientResponse;
import com.sun.jersey.api.client.WebResource;

public class JerseyClientGet {

  public static void main(String[] args) {
	try {

		Client client = Client.create();

		WebResource webResource = client
		   .resource("http://localhost:8080/RESTfulExample/rest/json/metallica/get");

		ClientResponse response = webResource.accept("application/json")
                   .get(ClientResponse.class);

		if (response.getStatus() != 200) {
		   throw new RuntimeException("Failed : HTTP error code : "
			+ response.getStatus());
		}

		String output = response.getEntity(String.class);

		System.out.println("Output from Server .... \n");
		System.out.println(output);

	  } catch (Exception e) {

		e.printStackTrace();

	  }

	}
}

Output…


Output from Server .... 

{"singer":"Metallica","title":"Enter Sandman"}

3. POST Request

Review last REST service.


@Path("/json/metallica")
public class JSONService {

	@POST
	@Path("/post")
	@Consumes(MediaType.APPLICATION_JSON)
	public Response createTrackInJSON(Track track) {

		String result = "Track saved : " + track;
		return Response.status(201).entity(result).build();
		
	}
	//...

Jersey client to send a “POST” request, with json data and print out the returned output.


package com.mkyong.client;

import com.sun.jersey.api.client.Client;
import com.sun.jersey.api.client.ClientResponse;
import com.sun.jersey.api.client.WebResource;

public class JerseyClientPost {

  public static void main(String[] args) {

	try {

		Client client = Client.create();

		WebResource webResource = client
		   .resource("http://localhost:8080/RESTfulExample/rest/json/metallica/post");

		String input = "{\"singer\":\"Metallica\",\"title\":\"Fade To Black\"}";

		ClientResponse response = webResource.type("application/json")
		   .post(ClientResponse.class, input);

		if (response.getStatus() != 201) {
			throw new RuntimeException("Failed : HTTP error code : "
			     + response.getStatus());
		}

		System.out.println("Output from Server .... \n");
		String output = response.getEntity(String.class);
		System.out.println(output);

	  } catch (Exception e) {

		e.printStackTrace();

	  }

	}
}

Output…


Output from Server .... 

Track saved : Track [title=Fade To Black, singer=Metallica]

Download Source Code

Download it – Jersey-Client-Example.zip (8 KB)

References

  1. JSON example with Jersey + Jackson
  2. Jersey client examples
  3. RESTful Java client with RESTEasy client framework
  4. RESTful Java client with java.net.URL
  5. RESTful Java client with Apache HttpClient