Question

create Java Servlets and deploying them onto a Java Servlet Container.

Part 1- Hello World Servlet For the first part of this assignment, you will deploy a simple “helloworld” servlet to the servlet container. The servlet simply displays “Hello World”.

Part 2– Counter For this part, you will create a servlet that displays a “counter” for the number of times the servlet has been accessed. You should also support resetting the counter back to 0. You should display a button (.e.g., “Reset Counter”) on the page displayed by URL above. When the button is pressed, your servlet should process the POST request and reset the counter to 0.

Answer 1

Note: Done accordingly. Please comment for any problem. Please Uprate. Thanks.

Download Project:

https://drive.google.com/open?id=1qaSS0MVTLHHeQG6R2oWdE2Uht9x_Y4lB

Code:

HelloWorld.java

package com.HomeworkLib.www;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
* Servlet implementation class HelloWorld
*/
@WebServlet("/HelloWorld")
public class HelloWorld extends HttpServlet {
   private static final long serialVersionUID = 1L;
private static long counter=0;
/**
* @see HttpServlet#HttpServlet()
*/
public HelloWorld() {
super();
// TODO Auto-generated constructor stub
}

   /**
   * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
   */
   protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
       // TODO Auto-generated method stub
       //response.getWriter().append("Served at: ").append(request.getContextPath());
       counter++;
       response.setContentType("text/html");
PrintWriter printWriter = response.getWriter();
printWriter.println("<h1>Hello World!</h1><br>Counter :"+counter);
  
printWriter.println("<form name=\"loginForm\" method=\"post\" action=\"HelloWorld\"><input type=\"submit\" value=\"Reset Counter\" /></form>");
   }

   /**
   * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
   */
   protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
       // TODO Auto-generated method stub
       counter=0;
       String referer = request.getHeader("Referer");
       response.sendRedirect(referer);
       //doGet(request, response);
   }

}

Output: