public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain)
            throws IOException, ServletException {
        
            HttpServletRequest req = (HttpServletRequest) request;
            HttpServletResponse res = (HttpServletResponse) response;
            
            HttpSession sessao = req.getSession();
            if (sessao.getAttribute("Pablo") != null){
                 chain.doFilter(request, response);
            }
            else {
                res.sendRedirect("../faces/login.xhtml");
            }
           
     
    }