Cookies and Sessions?

Question

I am trying to set the maxAge in cookies using this code
Cookie cookie = new Cookie("cookie1","test");
cookie.setMaxAge(360);
cookie.setComment("test comments");
response.addCookie(cookie);I am retrieving the cookie using this code:
Cookie[] cookieArray = request.getCookies();
if( cookieArray != null) {
    for( int i = cookieArray.length-1; i >= 0; i-- ) {
       Cookie cookie = cookieArray;
out.println("Cookie name is " + cookie.getName() + "<br>");
out.println("Cookie value is " + cookie.getValue() + "<br>");
out.println("Cookie age is " + cookie.getMaxAge() + "<br>");
out.println("cookie comment is " + cookie.getComment() + "<br>");
The name and value are returned, but the maxAge=-1 and the comment is null. Any idea why? I also tried setting the maxAge to 0 after the cookie has been set the first time. The cookie still persists. Does the cookie persist forever if the maxAge is not set?
Also, I was wondering if you can use httpSession after the browser closes. If the user closes the browser, is it possible to get the session back when they open it again by setting the maxInterval?

Answer 1

Nothing reading the API wouldn't cure...
"This class [Cookie] supports both the Version 0 (by Netscape) and Version 1 (by RFC 2109) cookie specifications. By default, cookies are created using Version 0 to ensure the best interoperability." ... "Comments are not supported by Netscape Version 0 cookies."
This partly explains the comment problem (see setVersion(int)), except that it doesn't necessarily mean the browser will send the comment back. So you can try setting it, but I would never expect it to be there when read back.
"public void setMaxAge(int expiry)
A positive value indicates that the cookie will expire after that many seconds have passed. Note that the value is the maximum age when the cookie will expire, not the cookie's current age.
A negative value means that the cookie is not stored persistently and will be deleted when the Web browser exits. A zero value causes the cookie to be deleted."
The default max age is -1 (or at least some negative value). As for get, again, I wouldn't assume that the browser will send this information back.
Generally, if the cookie name/value is present, it hasn't expired, so great. If you want to reset it even if it still exists, or wait til it no longer exists, that's up to you. I wouldn't rely on other information.
In particular, I don't think getting back the max age will help with anything. There is no way to tell from it anything useful from it. It's not like you could figure out how long it's been since it was set. It wouldn't return any value such as time remaining. If you wanted to do something like that, you could set another cookie with a timestamp as the value and read that later.