Persistent Cookies with Servlets

[Reema Patel]

I read the following quote in a book...

....once cookie is created, you have access only to its name and value. You can�t access cookie's maximum age, because the header contains only the name and value information.

Is this correct?
But, I did see a method called getMaxAge().
Also, I wrote a test servlet, shown below:

import javax.servlet.*;
import javax.servlet.http.*;
 
import java.io.*;
 
public class DisplayCookies extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
......


//get the cookies from the request
Cookie cookies[]=request.getKookies();//changed for JavaRanch naming rules
if(cookies!=null){
//loop through the cookie array
for(int i=0;i& lt;cookies.length;i++){
Cookie cookie=cookies[i];
response.addCookie(cookie);
    out.println("Cookie name: "+cookie.getName() +" has value: "+cookie.getValue() +" max age= "+cookie.getMaxAge());
   
}
}
else{
out.println("There are no cookies set for this request");
}

}
public void doPost(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
doGet(request,response);
}

}

It displays the session age as -1. But, while this cookie was created it was set as cookie.setMaxAge(30*60);

Any help shall be highly appreciated.

Thanks,
Reema

[D Rog]

I believe cookie spec doesn't specify that client should transfer cookie expiration time. Cookie: http header has very simple format as name=value,

[Ben Souther]

If you want to know exactly what gets sent, download the LiveHttpHeaders plugin for Firefox and hit your test servlet.
You will be able to see all of the headers (cookies included)

[D Rog]

When you do so, remember to use web site which sets a cookie, for example saloon.javaranch.com

[Reema Patel]

Thanks for posting.

Ben,
I don't really need to download anything, using FireFox I can go to Tools->Options->Privacy->Cookies->View Cookies, I get to know everything about a cookie. So, why would I need to download xyz s/w?


I have a very simple Q- Y

You can�t access cookie's maximum age, because the header contains only the name and value information

Is this correct?
Loking at the cookie data, I belive it'svery apt, then wat is the getMaxAge(
) doing in the Cookie class?

Thanks,
Reema

[Ben Souther]

Originally posted by Reema Patel:
Thanks for posting.

Ben,
I don't really need to download anything, using FireFox I can go to Tools->Options->Privacy->Cookies->View Cookies, I get to know everything about a cookie. So, why would I need to download xyz s/w?

Viewing the headers with a tool like LiveHttpHeaders or tcpflow shows you exactly what is being passed between the client and server.

[William Janssen]

Unless you set the maximum age of a cookie, with setmaxAge(int sec), the getMaxAge will always return -1 which is the default (for some cookies it can be confiugred within the appserver the application is executed). The scope is only the cookie object on which it is set.