Symfony - Création d'un espace sécurisé (Controllers)

AdminController.php

<?php
namespace AppBundle\Controller;

use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\HttpFoundation\Request;

/**
 * Class AdminController
 * @package AppBundle\Controller
 * @Route("/admin")
 */
class AdminController extends Controller {
    /**
     * @Route("/", name="admin_index")
     */
    public function indexAction() {
        // ...
    }

    /**
     * @Route("/login", name="login_check")
     */
    public function loginCheckAction() {}
  
    /**
     * @Route("/logout", name="logout")
     */
    public function logoutAction() {}
}

DefaultController.php

<?php
namespace AppBundle\Controller;

use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\HttpFoundation\Request;

class DefaultController extends Controller
{
    /**
     * @Route("/", name="homepage")
     */
    public function indexAction(Request $request)
    {
        // ...
    }
  
    /**
     * @Route("/login", name="login")
     */
    public function loginAction() {
        $helper = $this->get('security.authentication_utils');
      
        return $this->render('default/login.html.twig', array(
            'last_username' => $helper->getLastUsername(),
            'error' => $helper->getLastAuthenticationError()
        ));
    }
}