use Symfony\Component\DependencyInjection\ContainerInterface;
use Symfony\Component\Routing\RouterInterface;
use Symfony\Component\Routing\Generator\UrlGeneratorInterface;

class MyClass {
    public function __construct(ContainerInterface $container) {
	$router = $this->container->get('router');
	// URLの取得
	$router->generate("ルーティング名",array(),UrlGeneratorInterface::ABSOLUTE_URL);
    }
}