RouteSecurityListener.php

<?php

namespace OpenSky\Bundle\MainBundle\Listener;

use Symfony\Component\HttpKernel\Event\GetResponseEvent;
use Symfony\Component\Security\Core\Exception\AccessDeniedException;
use Symfony\Component\Security\Core\SecurityContextInterface;

/**
 * Listens to kernel.request after the router and checks required role.
 */
class RouteSecurityListener
{
    private $security;

    public function __construct(SecurityContextInterface $security)
    {
        $this->security = $security;
    }

    public function onKernelRequest(GetResponseEvent $event)
    {
        $request = $event->getRequest();

        $route = $request->attributes->get('_route');
        $role  = $request->attributes->get('_role');

        if ($role && !$this->security->isGranted($role)) {
            $message = $route
                ? sprintf('The "%s" route requires the "%s" role.', $route, $role)
                : sprintf('This route requires the "%s" role.', $role);

            throw new AccessDeniedException($message);
        }
    }
}

It's probably a bit of a micro-optimisation, but you don't really need to retrieve the $route unless you enter that if.

You can also use:

jms_security_extra:
    method_access_control:
        "AcmeFooBundle:Blog:edit": "hasRole('ROLE_EDITOR')"