Sessao

public class SessionCheckFilter implements Filter {
 private static int firstRequest = 0;
 public void doFilter(ServletRequest request, ServletResponse response,
                    FilterChain chain) throws IOException, ServletException {
      HttpServletRequest hreq = (HttpServletRequest)request;
      HttpServletResponse hres = (HttpServletResponse)response;
      HttpSession session = hreq.getSession();
      if (session.isNew()) {
          if(firstRequest == 0){
               firstRequest++;
          } else {
               hres.sendRedirect("faces/ErrorPage.jsp");
               return;
          }
      }
      chain.doFilter(request, response);
  }
  public void init(FilterConfig filterConfig) throws ServletException {}
  public void destroy() {}
}