Sample JAX-RS REST service in Jersey

In this post, we created a REST service from patterns in Netbeans IDE and now we will be creating one manually using Jersey in Eclipse.

Create the project

I'm using Mars 2 distribution of Eclipse. To create the project, select New→Dynamic Web Project under Web. 

I'm using Apache Tomcat server v8.0. Click Next and set the build class location and click Next. Make sure to Generate web.xml and click Finish.

Add Jersey to the project

From this Jersey download site, download the bundle( I downloaded  Jersey JAX-RS 2.0 RI bundle ) which is a zip file containing the jars and dependencies. Copy all the jars (in api, ext and lib directories) into our project's WebContent/WEB-INF/lib directory. Refresh the project in Eclipse to make sure they are loaded.

Create the class

Now it's time to add the class to set the messages. Let's add a package named hello to src (Note: this value will be used in web.xml) and create a class in it as follows:

package hello;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;

@Path("hello")
public class Hello {
    
    @GET
    @Produces(MediaType.TEXT_PLAIN)
    public String sayPlainTextHello() {
      return "Hello Jersey";
    }

}

Configure web.xml

Update the web.xml file as follows. This will register Jersey to handle requests.

<?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" 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>Hello World REST example</display-name>
 <servlet>
    <servlet-name>Jersey REST Service</servlet-name>
    <servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
    <init-param>
        <param-name>jersey.config.server.provider.packages</param-name>
        <param-value>hello</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
    <servlet-name>Jersey REST Service</servlet-name>
    <url-pattern>/rest/*</url-pattern>
  </servlet-mapping>
</web-app>

Run the service

You can run the service by right clicking on the project and choosing Run as →Run on server to run the service. Go to http://localhost:8080/HelloWorldREST/rest/hello to view the results.