Implementing a JAX-RS webservice with Jersey

In this tutorial we’ll create a JAX-RS webservice with the Jersey implementation. The Jersey is the best choice, if you have an older JBoss instance. But, if you have a JBoss 6.1, 7.1, EAP 6+, you should use RestEasy or Apache CXF.

Let’s create a Maven based web project(maven-webapp archetype). This is not the place of discussing it, I hope you have the skill to do it. If you did it, open the projects pom.xml file, and edit the <dependencies> part. Add the following dependency:

<dependency>

<groupId>com.sun.jersey</groupId>

<artifactId>jersey-server</artifactId>

<version>1.8</version>

</dependency>

This is the server side API of the Jersey JAX-RS implementation. Additionally, we have to set the Jersey’s custom remote repository, to do this, paste the upcoming lines into your pom.xml:

<repositories>

<repository>

<id>maven2-repository.java.net</id>

<name>Java.net Repository for Maven</name>

<url>http://download.java.net/maven/2/</url>

<layout>default</layout>

</repository>

</repositories>

Ok, we set up successfully our Maven project, now we’ll create a REST interface called HelloWorldWS. The name of the class is not important, because the path will be set by annotations:

package hu.developertutorials.java.jersey;

import javax.ws.rs.Path;

import javax.ws.rs.GET;

import javax.ws.rs.PathParam;

import javax.ws.rs.core.Response;

@Path("/hello")

public class HelloWorldWS {

@GET

@Path("/{param}")

public Response getMsg(@PathParam("param") String msg) {

String output = "Jersey say : " + msg;

return Response.status(200).entity(output).build();

}

}

The last item of the TODO list is to set up correctly the web.xml file.

<web-app id="WebApp_ID" version="2.5"

xmlns="http://java.sun.com/xml/ns/j2ee"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee

http://java.sun.com/xml/ns/j2ee/web-app_2_5.xsd">

<display-name>DeveloperTutorials Sample JAX-RS webapplication</display-name>

<servlet>

<servlet-name>jersey-servlet</servlet-name>

<servlet-class>

                    com.sun.jersey.spi.container.servlet.ServletContainer

               </servlet-class>

<init-param>

    <param-name>com.sun.jersey.config.property.packages</param-name>

    <param-value>hu.developertutorials.java.jersey</param-value>

</init-param>

<load-on-startup>1</load-on-startup>

</servlet>

<servlet-mapping>

<servlet-name>jersey-servlet</servlet-name>

<url-pattern>/*</url-pattern>

</servlet-mapping>

</web-app>