package examples.servlets;
import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
/**
* This simple servlet demonstrates how to create and retrieve a cookie, and
* how to set a maximum age on a cookie.
* It displays how many times it has been visited by all clients since
* the server was started, and displays how many times each client has visited
* successively within 10 seconds of each visit.
* Compile the servlet using the following line:
*
javac -d WEBLOGICHOME\classes CookieCounter.java
* where WEBLOGICHOME\classes is in your WebLogic Server's classpath.
*
* Copy the file "cookie.jpg" to
*
*
doc_root/images/cookie.jpg
*
* Where doc_root is the document root of your WebLogic Server. This
* is usually set to the "public_html" directory in your "myserver" directory.
* See
* Setting the document root for more details.
*
* Register the servlet in the weblogic.properties file by adding
* (or uncommenting) the following lines:
*
* weblogic.httpd.register.cookies=examples.servlets.CookieCounter
*
*
* Start (or restart) the WebLogic Server, and use a web browser to visit
* the following URL: http://localhost:7001/cookies
*
*
Although this is an unusually
* short-lived cookie, you may easily see the cookie count up, then expire by
* reloading the page several times, waiting more than 10 seconds, then
* reloading the page again. Try turning off cookies in your browser, the
* servlet no longer works. For a failsafe way to handle non-cookie-friendly
* web browsers, see the SessionServlet example.
*
* @author Copyright (c) 1996-98 by WebLogic, Inc. All Rights Reserved.
* @author Copyright (c) 1999-2000 by BEA Systems, Inc. All Rights Reserved.
*/
public class CookieCounter extends HttpServlet {
private int pageCount = 0;
/**
* Initializes the servlet. Looks for the property "initial" to set the
* pageCount variable.
*/
public void init(ServletConfig config) throws ServletException {
super.init(config);
String s = getInitParameter("initial");
if (s == null)
pageCount = 0;
else
pageCount = Integer.parseInt(s);
}
/**
* Implements the service method of the servlet.
*/
public void service(HttpServletRequest req, HttpServletResponse res)
throws IOException
{
boolean cookieFound = false;
Cookie thisCookie = null;
// We must set the content type before calling getWriter()
res.setContentType("text/html");
// Now we can call getWriter()
PrintWriter out = res.getWriter();
// Try to retrieve the cookie from the request.
Cookie[] cookies = req.getCookies();
for(int i=0; i < cookies.length; i++) {
thisCookie = cookies[i];
if (thisCookie.getName().equals("CookieCount")) {
cookieFound = true;
break;
}
}
if (cookieFound == false) {
// Create a new Cookie and set it's age.
thisCookie = new Cookie("CookieCount", "1");
thisCookie.setMaxAge(60*1);
// Add the new cookie to the response
res.addCookie(thisCookie);
}
out.println("
\n" +
"Cookie Counter\n" +
"\n" +
" " +
"Cookie Counter
");
pageCount++;
out.println("![](\"/images/cookie.jpg\")
");
out.println("");
out.println("
This page has been visited " + pageCount +
(pageCount==1?" time":" times") +
" before.\n");
// Display client specific count details
if (cookieFound) {
int cookieCount = Integer.parseInt(thisCookie.getValue());
cookieCount++;
// Set the new value of the cookie, and add it to the response
thisCookie.setValue(String.valueOf(cookieCount));
thisCookie.setMaxAge(10);
res.addCookie(thisCookie);
out.println("
You have visited this page " +
thisCookie.getValue() +
(cookieCount==1?" time":" times") +
" within the past 10 seconds.\n");
} else {
out.println("
Either you haven't visited this page recently, "+
"or your browser doesn't like cookies!\n");
}
out.println("");
}
}