The first step for creating a new project is to accumulate the required tools:
Java JDK (Version 6 or higher)
Eclipse IDE (Juno)
Apache Tomcat Server (Version 7) or Glassfish Server (Version 4.0)
Jersey Framework
Firstly, we will create a web project using Eclipse IDE. Go to File | New | Others | Dynamic Web Project. Follow the steps, and after the project is created, add the following libraries into the classpath:
asm-all-repackaged-2.2.0-b14.jarcglib-2.2.0-b14.jarguava-14.0.1.jarhk2-api-2.2.0-b14.jarhk2-locator-2.2.0-b14.jarhk2-utils-2.2.0-b14.jarjavax.annotation-api-1.2.jarjavax.inject-2.2.0-b14.jarjavax.ws.rs-api-2.0.jarjersey-client-2.2.jarjersey-common-2.2.jarjersey-container-servlet-core-2.2.jarjersey-server-2.2.jarosgi-resource-locator-1.0.1.jarvalidation-api-1.1.0.Final.jar
Now, we need to configure web.xml to the bound Jersey Container with the resources packages:
...........
<servlet>
<servlet-name>simpleJerseyExample</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.demo</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>simpleJerseyExample</servlet-name>
<url-pattern>/services/*</url-pattern>
</servlet-mapping>
...........A servlet container is treated as a controller to redirect the specified resource that is being called. jersey.config.server.provider.packages maps the resources that are available in the com.demo package. So, whenever any resource is being requested, ServletContainer checks into the com.demo package for the resource URI and serves the request accordingly.
The next step is to create the
Resource class that contains the business logic:
package com.demo;
import javax.ws.rs.Path;
import javax.ws.rs.Get;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.Produces;
/**
* helloWorld Root Resource
*/
@Path("helloWorld")
public class HelloWorldResource{
@GET
@PRODUCES(MediaType.TEXT_PLAIN)
public String greet(){
return "Hello World!!!";
}
}Tip
Downloading the example code
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A JAX-RS resource is an annotated POJO, which provides the so-called resource methods that are able to handle the HTTP requests for the URI paths bound to the resource. In the previous code, "helloWorld" is the resource URI:
@Path("helloWorld")To run the application, create a WAR file and deploy it on the Apache Tomcat Server. Once the project is deployed on the Tomcat server, we are ready to consume the "helloWorld" web service. We can type the resource URL in the browser or we can use curl:
$curl http://localhost:8080/projectName/services/helloWorld Hello World!!!