Introduction
Jersey as it states in the website, is more than just a reference implementation. It also has it’s own API that extends the specification toolkit with additional wrapped features and utilities to simplify RESTful service and client development. It also exposes numerous extension SPIs so that developers may extend Jersey to best suit their needs. For this post, we’re going to demonstrate how easy and simple it is to develop a RESTful service using this awesome technology!
What are we doing?
We’re doing a simple account details listing. So We will create a service that will display a json output of account details that can be parsed on the front-end.
1. Create a webapp using Maven and plug in the Jersey library
pom.xml
<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.javacodegeeks.areyes.jersey</groupId> <artifactId>jersey-example</artifactId> <packaging>war</packaging> <version>0.0.1-SNAPSHOT</version> <name>jersey-example Maven Webapp</name> <url>http://maven.apache.org</url> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>3.8.1</version> <scope>test</scope> </dependency> <dependency> <groupId>javax.ws.rs</groupId> <artifactId>javax.ws.rs-api</artifactId> <version>2.0.1</version> <scope>provided</scope> </dependency> <dependency> <groupId>com.sun.jersey</groupId> <artifactId>jersey-server</artifactId> <version>1.8</version> </dependency> </dependencies> <build> <finalName>jersey-example</finalName> </build> </project>
2. Additional configuration
We also need to put additional configurations on the web.xml file as we need the app to recognize our service.
web.xml
<web-app id="WebApp_ID" version="2.4"
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_4.xsd">
<display-name>Restful Web Application</display-name>
<servlet>
<servlet-name>jersey-serlvet</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.javacodegeeks.jersey.main</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>jersey-serlvet</servlet-name>
<url-pattern>/rs/*</url-pattern>
</servlet-mapping>
</web-app>
3. Create the Service
We now create the service. This service is located on the package we specified on the web.xml (com.sun.jersey.config.property.packages).
AccountDetailsService.java
package com.javacodegeeks.jersey.main;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.QueryParam;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;
@Path("account")
public class AccountDetailsService {
@GET
@Path("/details/{param}")
@Produces(MediaType.TEXT_PLAIN)
public Response getAccountDetails(@PathParam("param") String accountName) {
String output = "Account Name : " + accountName;
return Response.status(200).entity(output).build();
}
}
4. Let’s Test it!
Deploy your app to a J2EE container and go to:
http://localhost:8080/jersey-example/rs/account/details/
Download the Eclipse project of this tutorial:
You can download the full source code of this example here : jersey-example
