JAX-RS is a framework designed to help you write RESTful applications both on the client and server side. Jersey 2.0 which provides Reference Implementation for JAX-RS 2.0.
Project Structure
Jersey 2.0 provides support for Java SE HTTP Server, Grizzly 2 HTTP server, Servlet 2.5 or higher containers as well as OSGi containers on the server side and HTTPURLConnection - based or Grizzly asynchronous client transport connectors. To leverage JAX-RS/Jersey server-side async features in a Servlet container, you need a container that supports Servlet 3.0 at least. Jersey supports asynchronous resource invocations on Grizzly 2 HTTP server too.
Basic JAX-RS 2.0 Example:
Project Structure
web.xml
<?xml version="1.0" encoding="UTF-8"?> <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"> <display-name>JAX-RS-2.0_HelloWorld</display-name> <servlet> <servlet-name>Jersey Web Application</servlet-name> <servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class> <init-param> <param-name>jersey.config.server.provider.packages</param-name> <param-value>com.example</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>Jersey Web Application</servlet-name> <url-pattern>/webapi/*</url-pattern> </servlet-mapping> </web-app>
MyResource.java
package com.example; import javax.ws.rs.GET; import javax.ws.rs.Path; import javax.ws.rs.Produces; import javax.ws.rs.core.MediaType; /** * Root resource (exposed at "myresource" path) */ @Path("myresource") public class MyResource { /** * Method handling HTTP GET requests. The returned object will be sent * to the client as "text/plain" media type. * * @return String that will be returned as a text/plain response. */ @GET @Produces(MediaType.TEXT_PLAIN) public String getIt() { return "Got it!"; } }
index.jsp
<html> <body> <h2>Jersey RESTful Web Application!</h2> <p><a href="webapi/myresource">Jersey resource</a> <p>Visit <a href="http://jersey.java.net">Project Jersey website</a> for more information on Jersey! </body> </html>
Running on Apache Tomcat Server
Clicking on "Jersey resource" link will call MyResource web service
Thats all !!!