We will create a simple web application that will output the results based on the url pattern. We will use Jersey implementation to provide the JAX-RS web service capability.

Important JAX-RS annotations:

 

@Path	The URI path at which the class will be hosted.
@GET	The annotation will designate the method to process HTTP GET requests.
@POST	The annotation will designate the method to process HTTP POST method.
@PUT	The annotation will designate the method to process HTTP PUT method.
@DELTE	The annotation will designate the method to process HTTP DELTE method.
@PathParam	The URI path parameter is extracted from the request URI and copied into the declared variable.
@QueryParam	Query parameter is extracted from the request URI and copied into the declared variable.
@Consumes	The @Consumes annotation is used to specify the MIME media types of representations a resource can consume that were sent by the client.
@Produces	The @Produces annotation is used to specify the MIME media  types of representations a resource can produce and send back to the client: for example, "text/plain".

 

Create a dynamic web project using maven as shown here.

In order to use Jersey implementation for JAX-RS, we will need necessary jars to be downloaded. Add the following dependencies to your pom file and do Maven -> Update Project to get proper references to the jars.

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

	                <init-param>
<param-name>com.sun.jersey.config.property.packages</param-name>
<param-value>com.visionjava.restservices</param-value>
</init-param>

<!DOCTYPE web-app PUBLIC
 "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
 "http://java.sun.com/dtd/web-app_2_3.dtd" >

<web-app>
	<display-name>Archetype Created Web Application</display-name>
	<servlet>
		<servlet-name>rest-servlet</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.visionjava.restservices</param-value>
		</init-param>
		<init-param>
			<param-name>com.sun.jersey.api.json.POJOMappingFeature</param-name>
			<param-value>true</param-value>
		</init-param>
		<load-on-startup>1</load-on-startup>
	</servlet>

	<servlet-mapping>
		<servlet-name>rest-servlet</servlet-name>
		<url-pattern>/rest/*</url-pattern>
	</servlet-mapping>
</web-app>

package com.visionjava.restservices;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.core.Response;

@Path("/movies")
public class RestProcessor {
	@GET
	public Response getMsg() { 
		String output = "Movies Rest Service called with GET method:  " ; 
		return Response.status(200).entity(output).build(); 
	}
}

    @Path("/movies") designates our RestProcessor class to handle all the incoming URI's with pattern 

        http://localhost:8080/JAXRS-Example/rest/movies  

    @GET designates the getMsg() method to handle all the GET HTTP requests

@PathParam Example: 

        @GET
        @Path("/{param}")
public Response getMsg(@PathParam("param") String msg) { 
    String output = "Service Called with Param  : " + msg; 
return Response.status(200).entity(output).build(); 
        }

    @Path("/{param}") designates the method to handles with URi pattern /rest/movies/{parameter-value}

    @PathParam("param") will extract the  parameter-value and initialize variable msg with it.

@PathParam with subpath example:

        @GET    
@Path("/subgenre/{param}")
public Response getMsgThruSubpath(@PathParam("param") String arg ) {
    String output = "Subgenre requested is : " + arg; 
return Response.status(200).entity(output).build(); 
        }

@MatrixParam Example:

     @GET
     @Path("/{year}")
     public Response getBookList( @PathParam("year") String year,  @MatrixParam("director") String directorName )  {
        return Response.status(200).entity("Movies for Year + " + year + " with Director " + directorName).build();
     }