CkFinder with Java with session issue?

I'm current working with CkFinder on JSF 2.0 (don't mention about this because i bet that the issue did not came from JSF), running on GlassFish Server 3.1.

I want to use CkFinder to provide user's private folder (each user have their own folder - let assume that the folder existed when they upload file).

First, I read this Document: http://docs.cksource.com/CKFinder_2.x/Developers_Guide/Java/Configuration/Extending

As the document said, i wrote a PathBuilder for that...

    @Override
    public String getBaseUrl(HttpServletRequest request) {
        String userFolder = request.getSession(true).getAttribute("userFolder").toString();
        return "/personalUpload/" + userFolder + "/";
}