Why is my Symfony route is not working?

I made a new Symfony2 bundle and deleted the Acme bundle.

Then I created a new Controller (MainController.php):

<?php
namespace MyBlogBundleController;

class MainController extends Controller
{
    /**
     * @Route("/", name="index")
     * @Template()
     */
    public function indexAction()
    {

        return array();
    }

And a simple view: (Main/index.html.twig) which only contains a hello. My routing.yml is empty. When I run the whole project I get:

No route found for "GET /"
404 Not Found - NotFoundHttpException
1 linked Exception: ResourceNotFoundException »

What is wrong here and how to solve it?

Here is my routing debug:

Symfony>php app/console router:debug
[router] Current routes
Name                     Method Pattern
_wdt                     ANY    /_wdt/{token}
_profiler_search         ANY    /_profiler/search
_profiler_purge          ANY    /_profiler/purge
_profiler_info           ANY    /_profiler/info/{about}
_profiler_import         ANY    /_profiler/import
_profiler_export         ANY    /_profiler/export/{token}.txt
_profiler_phpinfo        ANY    /_profiler/phpinfo
_profiler_search_results ANY    /_profiler/{token}/search/results
_profiler                ANY    /_profiler/{token}
_profiler_redirect       ANY    /_profiler/
_configurator_home       ANY    /_configurator/
_configurator_step       ANY    /_configurator/step/{index}
_configurator_final      ANY    /_configurator/final

I also cleared the cache with no success.

Here is the routes.yml:

my_blog:
    resource: "@MyBlogBundle/Resources/config/routing.yml"
    prefix:   /

and the routing.yml in MyBlogBundle/Resources/config/routing.yml is empty.

Answer

The way your routes.yml is setup, you are requesting the routing.yml file from your bundle.

If you want to use annotations to manage the routes in your bundle, you have to write the routes.yml the following way:

my_blog:
    resource: "@MyBlogBundle/Controller/MainController.php"
    prefix:   /
    type:     annotation

And your controller needs to include the Route class from the FrameworkExtraBundle:

<?php
namespace MyBlogBundleController;

use SymfonyBundleFrameworkBundleControllerController;
use SensioBundleFrameworkExtraBundleConfigurationRoute;
use SensioBundleFrameworkExtraBundleConfigurationTemplate;

class MainController extends Controller
{
    /**
     * @Route("/", name="index")
     * @Template()
     */
    public function indexAction()
    {
        return array();
    }
}

This assumes you have installed the SensioFrameworkExtraBundle (http://symfony.com/doc/current/bundles/SensioFrameworkExtraBundle/index.html#installation).

More information on the route annotation: http://symfony.com/doc/current/bundles/SensioFrameworkExtraBundle/annotations/routing.html