RESTEasy Client for GET, POST, PUT and DELETE RESTFul APIs

In the previous tutorial, we have developed CRUD restful web services using RESTEasy.In this tutorial, we will learn how to build a RESTful client for consuming GET, POST, PUT and DELETE RESTFul APIs.

JAX-RS 2.0 Client API Overview

JAX-RS 2.0 introduces a new client API so that you can make HTTP requests to your remote RESTful web services. It is a 'fluent' request building API with really 3 main classes: Client, WebTarget, and Response
The Client interface is a builder of WebTarget instances. 
WebTarget represents a distinct URL or URL template from which you can build more sub-resource WebTargets or invoke requests on.
There are really two ways to create a Client. The standard way or you can use the ResteasyClientBuilder class. The advantage of the latter is that it gives you a few more helper methods to configure your client. Sample code:
            Client client = ClientBuilder.newClient();
            ... or...
            Client client = ClientBuilder.newBuilder().build();
            WebTarget target = client.target("http://foo.com/resource");
            Response response = target.request().get();
            String value = response.readEntity(String.class);
            response.close();  // You should close connections!

            ResteasyClient client = new ResteasyClientBuilder().build();
            ResteasyWebTarget target = client.target("http://foo.com/resource");

Update pom.xml File

Add a resteasy-client dependency in your pom.xml:
<dependency>
   <groupId>org.jboss.resteasy</groupId>
   <artifactId>resteasy-client</artifactId>
   <version>3.9.3.Final</version>
</dependency>

JAX-RS RESTEasy APIs

I will be re-using the codebase written for the RESTEasy CRUD example tutorial.
package net.javaguides.resteasy.resource;

import java.util.List;

import javax.ws.rs.Consumes;
import javax.ws.rs.DELETE;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.PUT;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;

import net.javaguides.resteasy.model.User;
import net.javaguides.resteasy.service.UserService;

/**
 * CRUD Rest APIs for User Resource
 * @author Ramesh Fadatare
 *
 */

@Path("users")
public class UserResource {

    private UserService userService = new UserService();

    @GET
    @Produces(MediaType.APPLICATION_JSON)
    public Response getUsers() {

        List < User > users = userService.findAll();

        if (!users.isEmpty()) {
            return Response.ok(users).build();
        } else {
            return Response.status(Response.Status.NOT_FOUND).build();
        }
    }

    @Path("/{id}")
    @GET
    @Produces(MediaType.APPLICATION_JSON)
    public Response getUserById(@PathParam("id") Long id) {

        User user = userService.fetchBy(id);

        if (user.getId() != null) {
            return Response.ok(user).build();
        } else {
            return Response.status(Response.Status.NOT_FOUND).build();
        }
    }

    @POST
    @Produces(MediaType.APPLICATION_JSON)
    @Consumes(MediaType.APPLICATION_JSON)
    public Response createUser(User user) {
        boolean result = userService.create(user);
        if (result) {
            return Response.ok().status(Response.Status.CREATED).build();
        } else {
            return Response.notModified().build();
        }
    }


    @PUT
    @Path("/{id}")
    @Consumes(MediaType.APPLICATION_JSON)
    public Response updateUser(@PathParam("id") long id, User user) {
        boolean result = userService.update(user);

        if (result) {
            return Response.ok().status(Response.Status.NO_CONTENT).build();
        } else {
            return Response.notModified().build();
        }
    }


    @Path("/{id}")
    @DELETE
    @Produces(MediaType.APPLICATION_JSON)
    public Response deleteUser(@PathParam("id") Long id) {
        boolean result = userService.delete(id);

        if (result) {
            return Response.ok().status(Response.Status.NO_CONTENT).build();
        } else {
            return Response.notModified().build();
        }
    }
}

RESTEasy Client for GET, POST, PUT and DELETE RESTFul APIs

Let's create a JUnit test cases to GET, POST, PUT and DELETE Rest web services with RESTEasy:
package net.javaguides.resteasy;

import javax.ws.rs.client.Entity;
import javax.ws.rs.core.Response;

import org.jboss.resteasy.client.jaxrs.ResteasyClient;
import org.jboss.resteasy.client.jaxrs.ResteasyClientBuilder;
import org.jboss.resteasy.client.jaxrs.ResteasyWebTarget;
import org.junit.Test;

import net.javaguides.resteasy.model.User;

public class UserResourceTest {

    private static final String FULL_PATH = "http://localhost:8080/resteasy-crud-example-tutorial/restapi/users";

    @Test
    public void testListAllUsers() {

        final ResteasyClient client = new ResteasyClientBuilder().build();
        final ResteasyWebTarget target = client
            .target(FULL_PATH);
        String response = target.request().get(String.class);
        System.out.println(response);
    }

    @Test
    public void testGetUser() {

        final ResteasyClient client = new ResteasyClientBuilder().build();
        final ResteasyWebTarget target = client
            .target(FULL_PATH + "/100");
        Response response = target.request().get();
        User user = response.readEntity(User.class);
        System.out.println(user.toString());
        response.close();
    }

    @Test
    public void testCreateUser() {
        ResteasyClient client = new ResteasyClientBuilder().build();
        ResteasyWebTarget target = client.target(FULL_PATH);
        Response response = target.request()
            .post(Entity.entity(new User(100 L, "Amir", "amir@gmail.com"), "application/json"));
        System.out.println(response.getStatus());
        response.close();
    }

    @Test
    public void testUpdateUser() {
        User user = new User();
        user.setName("Ram");
        user.setEmail("ram@gmail.com");
        ResteasyClient client = new ResteasyClientBuilder().build();
        ResteasyWebTarget target = client.target(FULL_PATH + "/100");
        Response response = target.request()
            .put(Entity.entity(user, "application/json"));
        System.out.println(response.getStatus());
        response.close();
    }

    @Test
    public void testDeleteUser() {
        ResteasyClient client = new ResteasyClientBuilder().build();
        ResteasyWebTarget target = client.target(FULL_PATH + "/101");
        Response response = target.request()
            .delete();
        System.out.println(response.getStatus());
        response.close();

        final ResteasyWebTarget target1 = client
            .target(FULL_PATH);
        String response1 = target1.request().get(String.class);
        System.out.println(response1);
    }
}

Output


Run above the JUnit test case to test all CRUD REST APIs. Here is the output of JUnit test cases:

Conclusion

In this tutorial, we have created RESTEasy client to test CRUD RESTFul web services with RESTEasy. The application was deployed on Tomcat.

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