Java RESTful example using jersey api

Before we proceed, we need almost four things up and running as part of our dev environment. Here I will be using following resources in order to design the simple RESTful service.

1. Eclipse
2. Tomcat
3. Jersey library
4. Maven

Jersey api is based on JAX-RS (JSR 311).

In nearly 4 steps we can configure and build the complete RESTful API.

1. Open up your Eclipse IDE and create a dynamic web project and then convert it into the Maven project.
2. Add the jersey-server dependency.
3. Configure the jersey-server class and package entry into the web.xml file.
4. Create the java class which will configure the url and request type and also will prepare the response.

 Maven Dependency:

Add below code snippet inside your pom.xml file. This will add the jersey-server library into the project.

      <dependency>
          <groupId>com.sun.jersey</groupId>
          <artifactId>jersey-server</artifactId>
          <version>1.8</version>
      </dependency>

web.xml

Add the below code snippet in your web.xml file.

<servlet>
        <servlet-name>my-jersey</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.services.rest</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>my-jersey</servlet-name>
        <url-pattern>/restful/*</url-pattern>
    </servlet-mapping>

Java Class:

Add the below java code into your java file.

package com.services.rest;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.core.Response;

@Path("/hello")
public class FirstRestService {
    
    @GET
    @Path("/{param}")    
    public Response sendMsg(@PathParam("param") String msg){
        
        String output = "<h1>Hello! this is a : </h1>" + "<p>"+msg+"</p>";
        return Response.status(200).entity(output).build();
    }
    
    @GET
    @Path("/greeting")
    public String response(){
        
        return "<h1>Hello World</h1>";
    }

}

That's pretty much it guys, now you may go ahead and run the server and run the below url

http://localhost:8080/MyProject/restful/hello/greeting
OR
http://localhost:8080/MyProject/restful/hello/restFulWorld