RESTEasy Tutorial Part-2: Spring Integration

RESTEasy Tutorial Series

RESTEasy Tutorial Part-1: Basics

RESTEasy Tutorial Part-2: Spring Integration

RESTEasy Tutorial Part 3 - Exception Handling

RESTEasy provides support for Spring integration which enables us to expose Spring beans as RESTful WebServices.

Step#1: Configure RESTEasy+Spring dependencies using Maven.

	<project xmlns="http://maven.apache.org/POM/4.0.0"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
	http://maven.apache.org/maven-v4_0_0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<groupId>com.sivalabs</groupId>
	<artifactId>resteasy-demo</artifactId>
	<version>0.1</version>
	<packaging>war</packaging>
	<properties>
	<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
	<org.springframework.version>3.1.0.RELEASE</org.springframework.version>
	<slf4j.version>1.6.1</slf4j.version>
	<java.version>1.6</java.version>
	<junit.version>4.8.2</junit.version>
	<resteasy.version>2.3.2.Final</resteasy.version>
	</properties>
	<build>
	<finalName>resteasy-demo</finalName>
	<plugins>
	<plugin>
	<groupId>org.apache.maven.plugins</groupId>
	<artifactId>maven-compiler-plugin</artifactId>
	<version>2.3.2</version>
	<configuration>
	<source>${java.version}</source>
	<target>${java.version}</target>
	</configuration>
	</plugin>
	</plugins>
	</build>
	<dependencies>
	<dependency>
	<groupId>junit</groupId>
	<artifactId>junit</artifactId>
	<version>${junit.version}</version>
	<scope>test</scope>
	</dependency>
	<dependency>
	<groupId>org.slf4j</groupId>
	<artifactId>slf4j-api</artifactId>
	<version>${slf4j.version}</version>
	</dependency>
	<dependency>
	<groupId>org.slf4j</groupId>
	<artifactId>jcl-over-slf4j</artifactId>
	<version>${slf4j.version}</version>
	<scope>runtime</scope>
	</dependency>
	<dependency>
	<groupId>org.slf4j</groupId>
	<artifactId>slf4j-log4j12</artifactId>
	<version>${slf4j.version}</version>
	<scope>runtime</scope>
	</dependency>
	<dependency>
	<groupId>log4j</groupId>
	<artifactId>log4j</artifactId>
	<version>1.2.16</version>
	<scope>runtime</scope>
	</dependency>
	<dependency>
	<groupId>org.springframework</groupId>
	<artifactId>spring-context-support</artifactId>
	<version>${org.springframework.version}</version>
	<exclusions>
	<exclusion>
	<artifactId>commons-logging</artifactId>
	<groupId>commons-logging</groupId>
	</exclusion>
	</exclusions>
	</dependency>
	<dependency>
	<groupId>org.springframework</groupId>
	<artifactId>spring-web</artifactId>
	<version>${org.springframework.version}</version>
	</dependency>
	<dependency>
	<groupId>org.jboss.resteasy</groupId>
	<artifactId>resteasy-jaxrs</artifactId>
	<version>${resteasy.version}</version>
	<scope>provided</scope>
	</dependency>
	<dependency>
	<groupId>org.jboss.resteasy</groupId>
	<artifactId>resteasy-jaxb-provider</artifactId>
	<version>${resteasy.version}</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.jboss.resteasy</groupId>
	<artifactId>resteasy-spring</artifactId>
	<version>2.3.0.GA</version>
	<exclusions>
	<exclusion>
	<artifactId>commons-logging</artifactId>
	<groupId>commons-logging</groupId>
	</exclusion>
	<exclusion>
	<artifactId>jaxb-impl</artifactId>
	<groupId>com.sun.xml.bind</groupId>
	</exclusion>
	<exclusion>
	<artifactId>sjsxp</artifactId>
	<groupId>com.sun.xml.stream</groupId>
	</exclusion>
	<exclusion>
	<artifactId>jsr250-api</artifactId>
	<groupId>javax.annotation</groupId>
	</exclusion>
	<exclusion>
	<artifactId>activation</artifactId>
	<groupId>javax.activation</groupId>
	</exclusion>
	</exclusions>
	</dependency>
	<dependency>
	<groupId>javax.servlet</groupId>
	<artifactId>servlet-api</artifactId>
	<version>2.5</version>
	<scope>provided</scope>
	</dependency>
	<dependency>
	<groupId>org.apache.httpcomponents</groupId>
	<artifactId>httpclient</artifactId>
	<version>4.1.2</version>
	</dependency>
	</dependencies>
	</project>

view raw RESTEasy+Spring-pom.xml hosted with ❤ by GitHub

Step#2: Configure RESTEasy+Spring in web.xml

	<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns="http://java.sun.com/xml/ns/javaee"
	xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
	http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
	id="WebApp_ID" version="3.0">
	<listener>
	<listener-class>org.jboss.resteasy.plugins.server.servlet.ResteasyBootstrap</listener-class>
	</listener>
	<listener>
	<listener-class>org.jboss.resteasy.plugins.spring.SpringContextLoaderListener</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>contextConfigLocation</param-name>
	<param-value>classpath:applicationContext.xml</param-value>
	</context-param>
	<context-param>
	<param-name>resteasy.servlet.mapping.prefix</param-name>
	<param-value>/rest</param-value>
	</context-param>
	<!--While using Spring integration set resteasy.scan to false or don't configure resteasy.scan parameter at all -->
	<context-param>
	<param-name>resteasy.scan</param-name>
	<param-value>false</param-value>
	</context-param>
	</web-app>

view raw RESTEasySpring-Web-New.xml hosted with ❤ by GitHub

Step#3: Create a Spring Service class UserService and update UserResource to use UserService bean.

	package com.sivalabs.resteasydemo;
	import java.util.List;
	import org.springframework.stereotype.Service;
	import com.sivalabs.resteasydemo.MockUserTable;
	@Service
	public class UserService
	{
	public void save(User user){
	MockUserTable.save(user);
	}
	public User getById(Integer id){
	return MockUserTable.getById(id);
	}
	public List<User> getAll(){
	return MockUserTable.getAll();
	}
	public void delete(Integer id){
	MockUserTable.delete(id);
	}
	}
	package com.sivalabs.resteasydemo;
	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.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 org.springframework.beans.factory.annotation.Autowired;
	import org.springframework.stereotype.Component;
	@Component
	@Path("/users")
	@Produces(MediaType.APPLICATION_XML)
	@Consumes(MediaType.APPLICATION_XML)
	public class UserResource
	{
	@Autowired
	private UserService userService;
	@Path("/")
	@GET
	public Response getUsersXML()
	{
	List<User> users = userService.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) {
	User user = userService.getById(id);
	return Response.ok(user).build();
	}
	@Path("/")
	@POST
	public Response saveUser(User user) {
	userService.save(user);
	return Response.ok("<status>success</status>").build();
	}
	@Path("/{id}")
	@DELETE
	public Response deleteUser(@PathParam("id") Integer id) {
	userService.delete(id);
	return Response.ok("<status>success</status>").build();
	}
	}
	applicationContext.xml
	<?xml version="1.0" encoding="UTF-8"?>
	<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:p="http://www.springframework.org/schema/p"
	xmlns:context="http://www.springframework.org/schema/context"
	xsi:schemaLocation="http://www.springframework.org/schema/beans
	http://www.springframework.org/schema/beans/spring-beans.xsd
	http://www.springframework.org/schema/context
	http://www.springframework.org/schema/context/spring-context.xsd">
	<context:annotation-config/>
	<context:component-scan base-package="com.sivalabs.resteasydemo"/>
	</beans>

view raw RESTEasy+Spring-Sample-Code.java hosted with ❤ by GitHub

Step#4: Same JUnit TestCase to test the REST Webservice described in Part-1.

	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:8080/resteasy-demo/rest/";
	@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+"users/1");
	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("application/xml", 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+"users/2");
	ClientResponse<String> response = request.delete(String.class);
	String statusXML = response.getEntity();
	Assert.assertNotNull(statusXML);
	}
	}

view raw UserResource-JUnit-TestCase.java hosted with ❤ by GitHub

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 /*

3. While using Spring integration set resteasy.scan to false or don't configure resteasy.scan parameter at all.
    Otherwise you may get REST Resource instances(UserResource) from RestEasy instead of Spring container. While running JUnit Tests I observed this random behavior.

4. You should register REST Resource as Spring bean by annotating with @Component or @Service.