Persistent Cookie Test Example

JSP Tutorials - Herong's Tutorial Examples

∟Persistent Cookie Test Example

This section provides a tutorial example on how to set a persistent cookie and set other properties of a cookie in JSP page.

The following JSP page shows you how to set a persistent cookie and how to use other properties.

<?xml version="1.0"?>
<jsp:root xmlns:jsp="http://java.sun.com/JSP/Page" version="2.3">
<!--
 - CookieProperties.jspx
 - Copyright (c) 2006 HerongYang.com. All Rights Reserved.
-->
<jsp:directive.page contentType="text/html"/>
<html><body>
<p>
<jsp:directive.page import="javax.servlet.http.Cookie"/>
<jsp:scriptlet><![CDATA[
// Setting a cookie with default properties
   out.println("<b>Cookie with default properties:</b><br/>");
   Cookie c = new Cookie("Date","01-Jan-2099");
   response.addCookie(c);
   out.println("Name: "+c.getName()+"<br/>");
   out.println("Value: "+c.getValue()+"<br/>");
   out.println("Domain: "+c.getDomain()+"<br/>");
   out.println("Path: "+c.getPath()+"<br/>");
   out.println("MaxAge: "+c.getMaxAge()+"<br/>");
   out.println("Version: "+c.getVersion()+"<br/>");

// Setting a cookie with specified properties
   out.println("<b>Cookie with specified properties:</b><br/>");
//   c = new Cookie("User","Herong Yang"); // space is not allowed
   c = new Cookie("User","HerongYang");
   c.setMaxAge(3*24*60*60);
   response.addCookie(c);
   out.println("Name: "+c.getName()+"<br/>");
   out.println("Value: "+c.getValue()+"<br/>");
   out.println("Domain: "+c.getDomain()+"<br/>");
   out.println("Path: "+c.getPath()+"<br/>");
   out.println("MaxAge: "+c.getMaxAge()+"<br/>");
   out.println("Version: "+c.getVersion()+"<br/>");

// Checking properties of the received cookies
   out.println("<b>Properties of the received cookies:</b><br/>");
   Cookie[] cookies = request.getCookies();
   int n = 0;
   if (cookies!=null) {
      n = cookies.length;
      for (int i=0; i<cookies.length; i++) {
         out.println("Name: "+cookies[i].getName()+"<br/>");
         out.println("Value: "+cookies[i].getValue()+"<br/>");
         out.println("Domain: "+cookies[i].getDomain()+"<br/>");
         out.println("Path: "+cookies[i].getPath()+"<br/>");
         out.println("MaxAge: "+cookies[i].getMaxAge()+"<br/>");
         out.println("Version: "+cookies[i].getVersion()+"<br/>");
      }
   }
]]></jsp:scriptlet>
</p>
</body></html>
</jsp:root>

Visit this page with IE, and you should see:

Cookie with default properties:
Name: Date
Value: 01-Jan-2099
Domain: null
Path: null
MaxAge: -1
Version: 0
Cookie with specified properties:
Name: User
Value: HerongYang
Domain: null
Path: null
MaxAge: 259200
Version: 0
Properties of the received cookies:

If you are using IE, click at IE "Settings > Tools" menu, selected "Internet Options...", and clicked the "Settings..." button in the "Browsing history" section of the "General" tab. You will see the "Temporary Internet Files and History Settings" dialog box.

Click "View files" button, you will see the cookie file called "cookie:herong@localhost/". Double click on that file, and it will open in Notepad:

User
HerongYang
localhost/
1024
2353942784
29567146
224352272
29566543
*

This proves that cookie "User=HerongYang" is persisted in a file on the hard disk.

Then you click the IE refresh button, you should get the following in the IE window:

Cookie with default properties:
Name: Date
Value: 01-Jan-2099
Domain: null
Path: null
MaxAge: -1
Version: 0
Cookie with specified properties:
Name: User
Value: HerongYang
Domain: null
Path: null
MaxAge: 259200
Version: 0

Properties of the received cookies:
Name: Date
Value: 01-Jan-2099
Domain: null
Path: null
MaxAge: -1
Version: 0
Name: User
Value: HerongYang
Domain: null
Path: null
MaxAge: -1
Version: 0
Name: JSESSIONID
Value: 37CB87D855A94F84355FE86626D2BAF7
Domain: null
Path: null
MaxAge: -1
Version: 0

It is interesting to know that:

The setMaxAge() did force the Web browser to save the cookie to the local hard disk.
The persisted cookie "User" has the default domain "localhost" and default path "null".
When this persisted cookie "User" was posted to the server again, the MaxAge value got reset to "-1" again.
Cookie "JSESSIONID" was added by the Web server, not by my program.