Jersey(1.19.1) - Hello World, Get started with Jersey using the embedded Grizzly server

Maven Dependencies

The following Maven dependencies need to be added to the pom:

<dependency>
    <groupId>com.sun.jersey</groupId>
    <artifactId>jersey-server</artifactId>
    <version>1.19.1</version>
</dependency>
<dependency>
    <groupId>com.sun.jersey</groupId>
    <artifactId>jersey-grizzly2</artifactId>
    <version>1.19.1</version>
</dependency>

Creating a root resource

Create the following Java class in your project:

package com.huey.hello.jersey.resources;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;

// The Java class will be hosted at the URI path "/helloworld"
@Path("helloworld")
public class HelloWorldResource {

    // The Java method will process HTTP GET requests
    @GET
    // The Java method will produce content identified by the MIME Media type "text/plain"
    @Produces("text/plain")
    public String sayHello() {
         // Return the textual content
        return "Hello World";
    }

}

The HelloWorldResource class is a very simple Web resource. The URI path of the resource is "/helloworld", it supports the HTTP GET method and produces cliched textual content of the MIME media type "text/plain".

Deploying the root resource

The root resource will be deployed using the Grizzly Web container.

 package com.huey.hello.jersey;

 import java.io.IOException;
 import java.net.URI;

 import javax.ws.rs.core.UriBuilder;

 import org.glassfish.grizzly.http.server.HttpServer;

 import com.sun.jersey.api.container.grizzly2.GrizzlyServerFactory;
 import com.sun.jersey.api.core.PackagesResourceConfig;
 import com.sun.jersey.api.core.ResourceConfig;

 public class HelloJersey {

     private static URI getBaseURI() {
         return UriBuilder.fromUri("http://localhost/").port(9998).build();
     }

     public static final URI BASE_URI = getBaseURI();

     protected static HttpServer startServer() throws IOException {
         System.out.println("Starting grizzly...");
         ResourceConfig rc = new PackagesResourceConfig("com.huey.hello.jersey.resources");
         return GrizzlyServerFactory.createHttpServer(BASE_URI, rc);
     }

     public static void main(String[] args) throws IOException {
         HttpServer httpServer = startServer();
         System.out.println(String.format("Jersey app started with WADL available at "
                         + "%sapplication.wadl\nTry out %shelloworld\nHit enter to stop it...",
                         BASE_URI, BASE_URI));
         System.in.read();
         httpServer.stop();
     }
 }

The HelloJersey class deploys the HelloWorldResource using the Grizzly Web container.

Line 24 creates an initialization parameter that informs the Jersey runtime where to search for root resource classes to be deployed. In this case it assumes the root resource class in the package com.huey.hello.jersey.resources (or in a sub-package of).

Line 25 deploys the root resource to the base URI "http://localhost:9998/" and returns a Grizzly HttpServer. The complete URI of the Hello World root resource is "http://localhost:9998/helloworld".

Testing the root resource

Goto the URI http://localhost:9998/helloworld in your favourite browser.

Or, from the command line use curl:

[huey@huey-K42JE ~]$ curl -i http://localhost:9998/helloworld
HTTP/1.1 200 OK
Content-Type: text/plain
Date: Wed, 13 Apr 2016 14:14:40 GMT
Transfer-Encoding: chunked

Hello World