Sunil's Notes: Createing Hello JAXRS service for deployment using Sun Jersey

If you want to build a REST service and deploy it in one of the Java EE 5 compliant containers for example WebSphere APplication Server 7.0, then you will have to use one of the external JAXRS containers such as Jersey, which is very popular among REST service developers.

I wanted to try this option out so i built a HelloJersey application that you can download from here. I followed these steps for building my sample application

First create a Dynamic Web APplication project called HelloJersey

Download following .jar files and add it to the WEB-INF/lib folder of your web application
1. asm-3.1.jar
2. jersey-core-1.5.jar
3. jersey-server-1.5.jar
4. jsr311-api-1.1.1.jar

Next create a HelloJerseyRESTService.java file like this


package com.webspherenotes.rest;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.QueryParam;
import javax.ws.rs.core.MediaType;

@Path("/hellojersey")
public class HelloJerseyRESTService {

  @GET
  @Produces(MediaType.TEXT_HTML)
  public String sayHello(@QueryParam("name") String name ){
    return "Hello " + name;
  }
}

The HelloJerseyRESTService only handles GET request and returns HTML markup

Next declare the Jersey servlet in the web.xml and create servlet mapping


<?xml version="1.0" encoding="UTF-8"?>
<web-app id="WebApp_ID" version="2.5"
  xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
  <display-name>DynaCacheSample1</display-name>
  <servlet>
    <servlet-name>Jersey REST Service</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>com.webspherenotes.rest</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>  
    <welcome-file-list>
      <welcome-file>index.html</welcome-file>
      <welcome-file>index.htm</welcome-file>
      <welcome-file>index.jsp</welcome-file>
      <welcome-file>default.html</welcome-file>
      <welcome-file>default.htm</welcome-file>
      <welcome-file>default.jsp</welcome-file>
    </welcome-file-list>
</web-app>

After you deploy the application in container you should see that when the server is starting it will scan all the resource and in our case it should find only com.webspherenotes.rest.HelloJerseyRESTService
[10/16/11 17:17:47:250 PDT] 0000000e ApplicationMg I WSVR0228I: User initiated module stop operation request completed on Module, HelloJersey.war, of application, DynaCacheSample1EAR [10/16/11 17:17:49:932 PDT] 0000000e ApplicationMg I WSVR0225I: User initiated module start operation requested on Module, HelloJersey.war, of application, DynaCacheSample1EAR [10/16/11 17:17:50:466 PDT] 0000000e webapp I com.ibm.ws.webcontainer.webapp.WebGroupImpl WebGroup SRVE0169I: Loading Web Module: HelloJersey. [10/16/11 17:17:50:521 PDT] 0000000e WASSessionCor I SessionContextRegistry getSessionContext SESN0176I: Will create a new session context for application key default_host/HelloJersey [10/16/11 17:17:50:602 PDT] 0000000e PackagesResou I Scanning for root resource and provider classes in the packages: com.webspherenotes.rest [10/16/11 17:17:50:666 PDT] 0000000e ScanningResou I Root resource classes found: class com.webspherenotes.rest.HelloJerseyRESTService [10/16/11 17:17:50:667 PDT] 0000000e ScanningResou I No provider classes found. [10/16/11 17:17:50:850 PDT] 0000000e WebApplicatio I Initiating Jersey application, version 'Jersey: 1.5 01/14/2011 12:36 PM' [10/16/11 17:17:51:816 PDT] 0000000e servlet I com.ibm.ws.webcontainer.servlet.ServletWrapper init SRVE0242I: [DynaCacheSample1EAR] [/HelloJersey] [Jersey REST Service]: Initialization successful. [10/16/11 17:17:51:817 PDT] 0000000e webcontainer I com.ibm.ws.wswebcontainer.VirtualHost addWebApplication SRVE0250I: Web Module HelloJersey has been bound to default_host[*:9080,*:80,*:9443,*:5060,*:5061,*:443]. [10/16/11 17:17:51:824 PDT] 0000000e ApplicationMg I WSVR0226I: User initiated module start operation request completed on Module, HelloJersey.war, of application, DynaCacheSample1EAR [10/16/11 17:17:51:825 PDT] 0000000e AppBinaryProc I ADMA7021I: Distribution of application DynaCacheSample1EAR completed successfully.