HttpSession session = event.getSession();
        ServletContext context = session.getServletContext();
        HashMap activeSessions = (HashMap) context.getAttribute("activeSessions");
        if (activeSessions == null) {
            activeSessions = new HashMap();
        }
        activeSessions.put(session.getId(), session);
        context.setAttribute("activeSessions", activeSessions);

HashMap activeSessions = (HashMap) request.getSession().getServletContext().getAttribute("activeSessions");

final HttpSession session = (HttpSession)activeSessions.get(jsessionid);

request.getSession()