Build RESTful Web service JASON data provider

This demo application will show you how to Build RESTful Web service JASON data provider Using JAX-RS and Jersey and test it with java client class.

Note: If you are not familiar with RESTful web service and need depth introduction on it before developing application please read this documentation: RESTful web service introduction

In this example, the method helloWorld() is annotated with @GET and the @Produces(“application/json”) annotation. This method will process JASON requests and produce content.

Below technology are needed to build application:

  • Eclipse Kepler
  • Java 1.6
  • Tomcat 7.0
  • JAX-RS 1.1
  • Jersey 1.8
  • Maven 3.0

Steps:

  • Create maven project name: RESTfulXMLAndJavaClient (If you are not sure how to create maven project in eclipse please follow this tutorial: Create Maven project eclipse)
  • Configure Tomcat server in eclipse (If you are not sure please follow this tutorial: Configure Tomcat server in eclipse)
  • Now create package name: com.javahonk inside src/main/java folder
  • Create class name HelloWorld.java and copy paste below code:

package com.javahonk;

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

@Path("/user")
public class HelloWorld {

	//HTML Request
	@GET
	@Path("/helloWorld")
	@Produces(MediaType.TEXT_HTML)
	public String helloWorld() {
		return "<html> " + "<title>" + "Hello World!" + "</title>"+ "<body><h1>" + "Hello World!" + "</body></h1>" + "</html> ";
	}

	// JASON request
	@GET
	@Path("/helloWorld")
	@Produces(MediaType.APPLICATION_JSON)
	public String sayJASONHello() {
		return "<?xml version=\"1.0\"?>"
				+ "<hello> Hello World from RESTful. It is APPLICATION_JSON request."
				+ "</hello>";
	}

}
  • Now create java client class to test RESTful web service. Create class name RESTfulTestClient.java inside package test and copy paste below code:

package test;

import java.net.URI;

import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.UriBuilder;

import com.sun.jersey.api.client.Client;
import com.sun.jersey.api.client.WebResource;
import com.sun.jersey.api.client.config.ClientConfig;
import com.sun.jersey.api.client.config.DefaultClientConfig;

public class RESTfulTestClient {

	public static void main(String[] args) {
	    ClientConfig config = new DefaultClientConfig();
	    Client client = Client.create(config);
	    WebResource service = client.resource(getBaseURI());

	    System.out.println(service.path("rest/user/helloWorld").accept(MediaType.TEXT_HTML).get(String.class));

	    System.out.println(service.path("rest/user/helloWorld").accept(MediaType.APPLICATION_JSON).get(String.class));	    

	  }

	  private static URI getBaseURI() {
	    return UriBuilder.fromUri("http://localhost:8080/RestFulService/").build();
	  }

}
  • Now copy paste below code in your web.xml file:
<!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>First RESTful Hello World</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.javahonk</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>

	<welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>

</web-app>

 

  • Copy below maven dependency jar into your pom.xml file:
<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.javahorn</groupId>
  <artifactId>RestFulService</artifactId>
  <packaging>war</packaging>
  <version>0.0.1-SNAPSHOT</version>
  <name>RestFulService 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>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>  
    <dependency>
	<groupId>com.sun.jersey</groupId>
	<artifactId>jersey-bundle</artifactId>
	<version>1.10-b01</version>
</dependency>  
  </dependencies>
  <build>
    <finalName>RestFulService</finalName>
  </build>
</project>
  • After all steps your project should look as below:

Build RESTful Web service JASON data provider

  • Now refresh and clean your project.
  • Deploy application on tomcat: Right click project –> Run As –> Run on Server
  • Now let’s test this with our java client RESTfulTestClient class. Run java test class: Right click java class –>Run As –> Java application. You will see below on your console. Great our test got successful.

Build RESTful Web service JASON data provider

download2 Download project: RESTfulXMLAndJavaClient

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