JSON and Servlet example

In the previous section of JSON-Java example youhave learned how to create a java class by usingJSON classes. Now inthis example we will tell you how to use JSON classes for creating Servlet.

In this example we have created  an object of JSONArrayand then we have added elements into this array by using the methodadd().To have functionality of JSON in your application you must have JSON-lib andits supported jar files. These are:commons-lang.jar,commons-beanutils.jar,commons-collections.jar,commons-logging.jar,ezmorph.jarand json-lib-2.2.2-jdk15.jar. 

Here is the example code of JSONServlet.java asfollows:

JSONServlet.java  

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import net.sf.json.JSONArray;

public class JSONServlet extends  HttpServlet{
  public void doGet(HttpServletRequest request,
  HttpServletResponse response)
   throws ServletException,IOException{
 JSONArray arrayObj=new JSONArray();
 arrayObj.add("MCA");
 arrayObj.add("Amit Kumar");
 arrayObj.add("19-12-1986");
 arrayObj.add(24);
 arrayObj.add("Scored");
 arrayObj.add(new Double(66.67));
  PrintWriter out = response.getWriter();
  out.println(arrayObj);
  for(int i=0;i<arrayObj.size();i++){
  out.println(arrayObj.getString(i));
  }
  }
}

We have to do corresponding servlet mapping into web.xmlas given below:

<?xml version="1.0" encoding="ISO-8859-1"?>

<web-app xmlns="http://java.sun.com/xml/ns/javaee"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
 http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
 version="2.5"> 
 <servlet>
  <servlet-name>JSONServlet</servlet-name>
  <servlet-class>JSONServlet</servlet-class>
  </servlet>
  <servlet-mapping>
  <servlet-name>JSONServlet</servlet-name>
  <url-pattern>/JSONServlet</url-pattern>
 </servlet-mapping>
</web-app>

To run this example follow this step by step procedure:

• create a JSONServlet.java class
• compile JSONServletand place it into WEB-INF/classes directory
• Download JSONLibraries and place it into Tomcat's libdirectory
• Start Tomcat Webserver and type
  http://localhost:8080/JSON/JSONServlet  into browser's address bar you will have following output on your browser.
  

Output:

Download JSON-Servlet Project code