protected void doPost(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException {

    HttpSession session = request.getSession();

    // la lógica de logueo está en el serivicio de login (LoginService) que devuelve un string con
    // la pantalla para el forward
    request
        .getRequestDispatcher(LoginService.validateLoginData(request, session))
        .forward(request, response);
  }
  protected void doGet(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException {

    String action = request.getParameter("action");

    if ("terminate".equals(action)) {
      // El usuario solicita desloguearse
      LoginService.closeSession(request);
      request.setAttribute("user", null);
      request.getRequestDispatcher("/index.jsp").forward(request, response);
    }
  }