Symfony2从事件侦听器重定向到URL

i need redirect to custom url from EventListener when symfony throws a exception

in my service.yml

app.exception_listener:
    class: AppBundle\EventListener\ExceptionListener
    tags:
        - { name: kernel.event_listener, event: kernel.exception, method: onKernelException  }

in my php class

<?php

namespace AppBundle\EventListener;

use Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpKernel\Exception\HttpExceptionInterface;
use Symfony\Component\DependencyInjection\Container;
use Symfony\Component\HttpFoundation\RedirectResponse;

class ExceptionListener {

public function onKernelException(GetResponseForExceptionEvent $event) {
    // You get the exception object from the received event
    $exception = $event->getException();

    if ($exception instanceof NotFoundHttpException) {

        //i need this function
        return $this->redirect('https://www.google.co.ve/?gws_rd=ssl', 404);
    }
}

}

Instead of:

return $this->redirect('https://www.google.co.ve/?gws_rd=ssl', 404);

do:

$event->setResponse(new RedirectResponse('https://www.google.co.ve/?gws_rd=ssl'));

Also note that it does not really make sense to send a Location header with a 404 response, you should use a response in the 3xx range. Symfony will actually (rightfully) throw an exception when trying to redirect with another status code.