AppserverIo\Appserver\ServletEngine\Security\RealmInterface::getExceptionStack PHP Method

    public function getExceptionStack();

 /**
  * Will be invoked when login fails for some reasons.
  *
  * @param \AppserverIo\Appserver\ServletEngine\Security\RealmInterface $realm           The realm instance containing the exception stack
  * @param \AppserverIo\Psr\Servlet\Http\HttpServletRequestInterface    $servletRequest  The servlet request instance
  * @param \AppserverIo\Psr\Servlet\Http\HttpServletResponseInterface   $servletResponse The servlet response instance
  *
  * @return void
  */
 protected function onFailure(RealmInterface $realm, HttpServletRequestInterface $servletRequest, HttpServletResponseInterface $servletResponse)
 {
     // load the session from the request
     if ($session = $servletRequest->getSession()) {
         // prepare the ArrayList for the login errors
         $formErrors = new ArrayList();
         // transform the realm's exception stack into simple error messages
         foreach ($realm->getExceptionStack() as $e) {
             $formErrors->add($e->getMessage());
         }
         // add the error messages to the session
         $session->putData(Constants::FORM_ERRORS, $formErrors);
     }
     // forward to the configured error page
     $this->forwardToErrorPage($servletRequest, $servletResponse);
 }