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>CountServlet</servlet-name>
  <servlet-class>r4r.servlet.CountServlet</servlet-class>
</servlet>
<servlet-mapping>
  <servlet-name>CountServlet</servlet-name>
  <url-pattern>/CountServlet</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-servlet</title>
</head>
<body>
<form>
<h1>Access Servlet by servlet's Name!</h1>
<a href="CountServlet">CountServlet</a>
</form>
</body>
</html>

Servlet Program

/*
 * Save as a CountServlet.java
 */
package r4r.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
 *
 * @author R4R
 */
public class CountServlet extends HttpServlet {
private int value = 0;
protected void processRequest(HttpServletRequest request,
	 HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
try {
/* 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>Servlet CountServlet at " 
	 + request.getContextPath() + "</h1>");
out.println("<form name=\"form\" action=\
             "CountServlet\" method=\"POST\">");
out.println("<BR>Enter Firstname :");
out.println("<input type=\"text\" name=\
             "fname\" value=\"\" size=\"20\" />");
out.println("<BR>Enter Lastname :");
out.println("<input type=\"text\" name=\
               "lname\" value=\"\" size=\"20\" />");
out.println("<BR> <input type=\"submit\" value=\
             "Submit Form\" name=\"submit\" />");
out.println("<input type=\"reset\" value=\"Reset Form \" />");
out.println("</form>");
out.println("</body>");
out.println("</html>");
} finally {
out.close();
}
}

@Override
protected void doGet(HttpServletRequest request,
	  HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}

@Override
protected void doPost(HttpServletRequest request,
	HttpServletResponse response)
throws ServletException, IOException {
// processRequest(request, response);
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
// increment value by 1 on every refresh of this page
String count = " " + ++value + " time";
// Get value form TextFiled
String fname = request.getParameter("fname");
String lname = request.getParameter("lname");
// User can't allow to leave any field empty
if ((!fname.equals("")) && (!lname.equals(""))) {
out.println("<html>");
out.println("<head>");
out.println("<body>");
out.println("<b>Hello:" + fname + " " + lname + "</b>");
//print name of viewer
out.println("<br>viewer:" + count);                                             
//print count digit
out.println("</body>");
out.println("</html>");
} else {
out.println("Please don't leave any textfield empty!");
out.println("<BR><a href=\"CountServlet\">Return to home Page</a>");
}
out.close(); //close text-output stream
}

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