Create RESTful Web Service Hello World

Create RESTful Web Service Hello World

This demo application will show you how to create Simple Hello World Application Using JAX-RS and Jersey.

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(“text/html”) annotation. This method will process HTTP GET requests and produce content in HTML.

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: FirstRESTfulHelloWorld (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 {

	 @GET
	 @Path("/helloWorld")
	 @Produces(MediaType.TEXT_HTML)
	 public String helloWorld() {

		return "<html> " + "<title>" + "Hello World!" + "</title>"+ "<body><h1>" + "Hello World!" + "</body></h1>" + "</html> ";

	}

}

 

  • Create index.jsp inside webapp and copy paste below code:
<html>
<title>Hello World!</title>
<head>
</head>
<body>
	<h2>Show me first RESTful Hello World!</h2>

	<form id="userForm" action="rest/user/helloWorld" method="GET">
		<table>			
			<tr>
				<td><input type="submit" value="Submit" /></td>				
			</tr>
		</table>
	</form>

</body>
</html>

 

  • Copy paste 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>
  • 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>

 

  • After all steps your project should look as below:

Create RESTful Web Service Hello World

  • Now refresh and clean your project.
  • To run project: Right click project –> Run As –> Run on Server
  • You will see below first index.jsp page click Submit button:

Create RESTful Web Service Hello World

 

  • Once you click submit button you will see below Hello World page:

Create RESTful Web Service Hello World

 

  • That’s it. We have created our first RESTful web service.

download2 Download project: FirstRESTfulHelloWorld

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