MyServlet.java Source code

Introduction

Here is the source code for MyServlet.java
Source

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.util.*;

public class MyServlet extends HttpServlet {

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, java.io.IOException {

        Cookie cookie = null;
        //Get an array of Cookies associated with this domain
        Cookie[] cookies = request.getCookies();
        boolean newCookie = false;

        //Get the 'mycookie' Cookie if it exists
        if (cookies != null) {
            for (int i = 0; i < cookies.length; i++) {
                if (cookies[i].getName().equals("mycookie")) {
                    cookie = cookies[i];
                }
            } //end for
        } //end if

        if (cookie == null) {
            newCookie = true;
            //Get the cookie's Max-Age from a context-param element
            //If the 'cookie-age' param is not set properly
            //then set the cookie to a default of -1, 'never expires'
            int maxAge;
            try {
                maxAge = new Integer(getServletContext().getInitParameter("cookie-age")).intValue();
            } catch (Exception e) {
                maxAge = -1;
            }

            //Create the Cookie object

            cookie = new Cookie("mycookie", "" + getNextCookieValue());
            cookie.setPath(request.getContextPath());
            cookie.setMaxAge(maxAge);
            response.addCookie(cookie);

        } //end if
          // get some info about the cookie
        response.setContentType("text/html");
        java.io.PrintWriter out = response.getWriter();

        out.println("<html>");
        out.println("<head>");
        out.println("<title>Cookie info</title>");
        out.println("</head>");
        out.println("<body>");

        out.println("<h2> Information about the cookie named \"mycookie\"</h2>");

        out.println("Cookie value: " + cookie.getValue() + "<br>");
        if (newCookie) {
            out.println("Cookie Max-Age: " + cookie.getMaxAge() + "<br>");
            out.println("Cookie Path: " + cookie.getPath() + "<br>");
        }

        out.println("</body>");
        out.println("</html>");

        out.close();
    }

    private long getNextCookieValue() {

        /*This produces a cookie value to show how to create Cookie objects. If 
          this method was heavily used in a production environment it may
          produce too many objects; synchronization of a single Date object
          might be better, based on performance testing. At any rate a
          production environment would produce a unique cookie value in a
          different manner such as from a unique database ID. */

        //returns the number of milleseconds since Jan 1, 1970
        return new java.util.Date().getTime();

    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, java.io.IOException {

        doGet(request, response);
    }
}