Enterprise Java

RESTEasy Tutorial Part-1: Basics

RESTEasy is a JAX-RS implementation from JBoss/RedHat and is in-built in JBoss 6 onwards.
Here I am going to show you how to develop a Simple RESTful Web Services application using RESTEasy and JBossAS7.1.1.FINAL.
 
 
 
 
 
 
 
 
Step#1: Configure RESTEasy dependencies using Maven.

 <project xmlns='http:maven.apache.orgPOM4.0.0' 
   xmlns:xsi='http:www.w3.org2001XMLSchema-instance'
   xsi:schemaLocation='http:maven.apache.orgPOM4.0.0 
   http:maven.apache.orgmaven-v4_0_0.xsd'>
   <modelVersion>4.0.0<modelVersion> 
 
   <groupId>com.sivalabs<groupId>
   <artifactId>resteasy-demo<artifactId>
   <version>0.1<version>  
   <packaging>war<packaging>
   <name>resteasy-demo Maven Webapp<name>
     
   <build>
     <finalName>resteasy-demo<finalName>
   <build>
   
   <dependencies>
   
     <dependency>
       <groupId>junit<groupId>
       <artifactId>junit<artifactId>
    <version>4.8.2<version>
       <scope>test<scope>
     <dependency>
 
     <dependency>
      <groupId>org.jboss.resteasy<groupId>
      <artifactId>resteasy-jaxrs<artifactId>
   <version>2.3.2.FINAL<version>
      <scope>provided<scope>
     <dependency>
 
     <dependency>
      <groupId>org.jboss.resteasy<groupId>
      <artifactId>resteasy-jaxb-provider<artifactId>
   <version>2.3.2.FINAL<version>
      <scope>provided<scope>
     <dependency>
 
     <dependency>
      <groupId>org.jboss.resteasy<groupId>
      <artifactId>jaxrs-api<artifactId>
      <version>2.3.0.GA<version>
      <scope>provided<scope>
     <dependency>
  <dependency>
         <groupId>org.apache.httpcomponents<groupId>
         <artifactId>httpclient<artifactId>
         <version>4.1.2<version>
   <scope>provided<scope>
     <dependency>
   <dependencies>
   
 <project>

Step#2: Configure RESTEasy in web.xml

 <web-app xmlns:xsi='http:www.w3.org2001XMLSchema-instance' 
   xmlns='http:java.sun.comxmlnsjavaee' 
   xmlns:web='http:java.sun.comxmlnsjavaeeweb-app_2_5.xsd' 
   xsi:schemaLocation='http:java.sun.comxmlnsjavaee 
   http:java.sun.comxmlnsjavaeeweb-app_3_0.xsd' 
   id='WebApp_ID' version='3.0'>
 
   <listener>
     <listener-class>org.jboss.resteasy.plugins.server.servlet.ResteasyBootstrap<listener-class>
   <listener>
   <servlet>
     <servlet-name>Resteasy<servlet-name>
     <servlet-class>org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher<servlet-class>
   <servlet>
   <servlet-mapping>
     <servlet-name>Resteasy<servlet-name>
     <url-pattern>rest*<url-pattern>
   <servlet-mapping>
   <context-param>
     <param-name>resteasy.servlet.mapping.prefix<param-name>
     <param-value>rest<param-value>
   <context-param>
   <context-param>
         <param-name>resteasy.scan<param-name>
         <param-value>true<param-value>
     <context-param>
 <web-app>

Step#3: Create User domain class, MockUserTable class to store User objects in-memory for testing purpose and UserResource class to expose CRUD operations on User as RESTful webservices.

 package com.sivalabs.resteasydemo;
 
 import java.util.Date;
 
 import javax.xml.bind.annotation.XmlAccessType;
 import javax.xml.bind.annotation.XmlAccessorType;
 import javax.xml.bind.annotation.XmlRootElement;
 
 @XmlRootElement
 @XmlAccessorType(XmlAccessType.FIELD)
 public class User 
 {
  private Integer id;
  private String name;
  private String email;
  private Date dob;
  setters and getters
 }
 
 
 package com.sivalabs.resteasydemo;
 
 import java.util.ArrayList;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
 import com.sivalabs.resteasydemo.User;
 
 public class MockUserTable 
 {
 
  private static Map<Integer, User> USER_MAP = new HashMap<Integer, User>();
  static
  {
   USER_MAP.put(1, new User(1,'admin','admin@gmail.com',new Date()));
   USER_MAP.put(2, new User(2,'test','test@gmail.com',new Date()));
  }
 
  public static void save(User user){
   USER_MAP.put(user.getId(), user);
  }
 
  public static User getById(Integer id){
   return USER_MAP.get(id);
  }
 
  public static List<User> getAll(){
   List<User> users = new ArrayList<User>(USER_MAP.values());
   return users;
  }
  public static void delete(Integer id){
   USER_MAP.remove(id);
  } 
 }
 
 
 package com.sivalabs.resteasydemo;
 
 import java.util.List;
 
 import javax.ws.rs.DELETE;
 import javax.ws.rs.GET;
 import javax.ws.rs.POST;
 import javax.ws.rs.Path;
 import javax.ws.rs.PathParam;
 import javax.ws.rs.Produces;
 import javax.ws.rs.core.GenericEntity;
 import javax.ws.rs.core.MediaType;
 import javax.ws.rs.core.Response;
 
 import com.sivalabs.resteasydemo.MockUserTable;
 
 @Path('users')
 @Produces(MediaType.APPLICATION_XML)
 public class UserResource 
 {
 
  @Path('')
  @GET
  public Response getUsersXML() 
  {
   List<User> users = MockUserTable.getAll();
   GenericEntity<List<User>> ge = new GenericEntity<List<User>>(users){};
   return Response.ok(ge).build();
  }
 
  @Path('{id}')
  @GET
  public Response getUserXMLById(@PathParam('id') Integer id) {
   return Response.ok(MockUserTable.getById(id)).build();
  }
 
  @Path('')
  @POST
  public Response saveUser(User user) {
   MockUserTable.save(user);
   return Response.ok('<status>success<status>').build();
  }
 
  @Path('{id}')
  @DELETE
  public Response deleteUser(@PathParam('id') Integer id) {
   MockUserTable.delete(id);
   return Response.ok('<status>success<status>').build();
  }
 
 }

Step#6: JUnit TestCase to test the REST Webservice.

 package com.sivalabs.resteasydemo;
 
 import java.util.List;
 
 import org.jboss.resteasy.client.ClientRequest;
 import org.jboss.resteasy.client.ClientResponse;
 import org.jboss.resteasy.util.GenericType;
 import org.junit.Assert;
 import org.junit.Test;
 
 import com.sivalabs.resteasydemo.User;
 
 public class UserResourceTest {
 
  static final String ROOT_URL = 'http:localhost:8080resteasy-demorest';
 
  @Test
  public void testGetUsers() throws Exception 
  {
   ClientRequest request = new ClientRequest(ROOT_URL+'users');
   ClientResponse<List<User>> response = request.get(new GenericType<List<User>>(){});
   List<User> users = response.getEntity();
   Assert.assertNotNull(users);
  }
 
  @Test
  public void testGetUserById() throws Exception 
  {
   ClientRequest request = new ClientRequest(ROOT_URL+'users1');
   ClientResponse<User> response = request.get(User.class);
   User user = response.getEntity();
   Assert.assertNotNull(user);
  }
 
  @Test
  public void testSaveUser() throws Exception 
  {
   User user = new User();
   user.setId(3);
   user.setName('User3');
   user.setEmail('user3@gmail.com');
 
   ClientRequest request = new ClientRequest(ROOT_URL+'users');
   request.body('applicationxml', user);
   ClientResponse<String> response = request.post(String.class);
 
   String statusXML = response.getEntity();
   Assert.assertNotNull(statusXML);
  }
 
  @Test
  public void testDeleteUser() throws Exception 
  {
   ClientRequest request = new ClientRequest(ROOT_URL+'users2');
   ClientResponse<String> response = request.delete(String.class);
   String statusXML = response.getEntity();
   Assert.assertNotNull(statusXML);
  }
 }

Step#7: To test the REST service we can use the REST Client Tool.
You can download REST Client Tool at http://code.google.com/a/eclipselabs.org/p/restclient-tool/

Important Things to Keep in mind:
1. org.jboss.resteasy.plugins.server.servlet.ResteasyBootstrap Listener should be registered before any other listener.

2. You should configure resteasy.servlet.mapping.prefix <context-param> if the HttpServletDispatcher servlet url-pattern is anything other than /*

Continue to the second part of this tutorial.

Reference: RESTEasy Tutorial Part-1: Basics from our JCG partner Siva Reddy at the My Experiments on Technology blog.

Siva Reddy

Katamreddy Siva Prasad is a Senior Software Engineer working in E-Commerce domain. His areas of interest include Object Oriented Design, SOLID Design principles, RESTful WebServices and OpenSource softwares including Spring, MyBatis and Jenkins.
Subscribe
Notify of
guest

This site uses Akismet to reduce spam. Learn how your comment data is processed.

3 Comments
Oldest
Newest Most Voted
Inline Feedbacks
View all comments
hossein761
11 years ago

Guess you need to at this to the pom.xml to make it work:

jboss
http://repository.jboss.org/nexus/content/groups/public-jboss/

John
John
10 years ago

The code has hundreds of errors. when executed. can you please post the code which actually works so that I can utilise the resteasy in my own applications. org.jboss.resteasy.plugins.providers.jaxb.JAXBUnmarshalException: Unable to find JAXBContext for media type: text/html;charset=”iso-8859-1″ at org.jboss.resteasy.plugins.providers.jaxb.CollectionProvider.readFrom(CollectionProvider.java:89) at org.jboss.resteasy.core.interception.MessageBodyReaderContextImpl.proceed(MessageBodyReaderContextImpl.java:105) at org.jboss.resteasy.plugins.interceptors.encoding.GZIPDecodingInterceptor.read(GZIPDecodingInterceptor.java:61) at org.jboss.resteasy.core.interception.MessageBodyReaderContextImpl.proceed(MessageBodyReaderContextImpl.java:108) at org.jboss.resteasy.client.core.BaseClientResponse.readFrom(BaseClientResponse.java:398) at org.jboss.resteasy.client.core.BaseClientResponse.getEntity(BaseClientResponse.java:346) at org.jboss.resteasy.client.core.BaseClientResponse.getEntity(BaseClientResponse.java:307) at com.sivalabs.resteasydemo.UserResourceTest.testGetUsers(UserResourceTest.java:28) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15) at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41) at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20) at org.junit.runners.BlockJUnit4ClassRunner.runNotIgnored(BlockJUnit4ClassRunner.java:79) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:71) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:49) at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193) at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52) at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191) at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42) at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184) at org.junit.runners.ParentRunner.run(ParentRunner.java:236) at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:49) at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683) at… Read more »

Savani
Savani
7 years ago

Could you please update your tutorials for resteasy-jaxrs for version 3.0.16 (i.e for 3.0.x) ? I think 3.x version has made lots of changes in their API’s, your updated tutorial will help all your followers to understand better. Please do the needful.

Back to top button