Java Servlet Programing Laungage

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0"
	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_3_0.xsd">
   <servlet>
	<servlet-name>phoneListServlet</servlet-name>
    <servlet-class>r4r.GenericServlet.phoneListServlet</servlet-class>
   </servlet>
   <servlet-mapping>
    <servlet-name>phoneListServlet</servlet-name>
    <url-pattern>/phoneListServlet</url-pattern>
   </servlet-mapping>
   <session-config>
     <session-timeout>
           30
     </session-timeout>
   </session-config>
</web-app>

Index.jsp

<%-- 
  Document   : index.jsp
--%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>r4r.co.in-GenericServlet</title>
 </head>
 <body>
  <form>
   <h1>Access GenericServlet by servlet's Name!</h1>
   <a href="phoneListServlet">phoneListServlet</a>
   </form>
 </body>
</html>

Servlet Program

/*
 * Save as a phoneListServlet.java
*/
package r4r.GenericServlet;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;
import javax.servlet.GenericServlet;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
/**
 *
 * @author R4R
*/
public class phoneListServlet extends GenericServlet 
{
//declaration and initialization 
private Map map = new HashMap();
@Override
public void service(ServletRequest req,
	ServletResponse res)throws ServletException,IOException
  {
 res.setContentType("text/html;charset=UTF-8");
 PrintWriter out = res.getWriter();
	/* TODO output your page here */
 out.println("<html>");
 out.println("<head>");
 out.println("<title>" + getServletInfo() + "</title>");
 out.println("</head>");
 out.println("<body>");
 out.println("<h1>Welcome to phoneListServlet</h1>");
 out.println("<form action=\"phoneListServlet\">");
out.println
("Enter name:<input type=\"text\"name=\"name\
"value=\"\"size=\"30\"maxlength=\"15\"/><BR>");
out.println
("Enter phone:<input type=\"text\" name=\"phone\
"value=\"\"size=\"30\"maxlength=\"12\"/><BR>");
  out.println("<input type=\"submit\" value=\
  "Save Record\" name=\"submit\" />");
  out.println("<input type=\"submit\
  " value=\"Reset Record\" />");
  out.println("</form>");
  out.println("</body>");
  out.println("</html>");

 /* ------------------------------ ----------------- */
if ((req.getParameter("submit")) != null)
	{
	String name = req.getParameter("name");
 long phone = Long.parseLong(req.getParameter("phone")); //Type conversion
 map.put(name, phone); //Store data into HashMap
	// Get data into Short order
	map = new TreeMap(map);
 printMap(out, map, "DataInsert into map:");
 }
 }
 private void printMap
	(PrintWriter out, Map map, String string)
	{
  out.println(string);
  Set entries = map.entrySet();
  Iterator iterator = entries.iterator();
  while (iterator.hasNext()) {
 Map.Entry object = (Map.Entry) iterator.next();
 out.println("<BR>" + object.getKey() + " : " + object.getValue());
 }
  out.println("<BR>");
 }

 @Override
 public String getServletInfo() {
  return "r4r.co.in-phoneListServlet";
 }
}