title: Symfony 3 service not found exception
body: <p>I have a Tree like this:</p>
  
  <pre><code>src
  `-- AppBundle  
      |-- AppBundle.php   
      |-- Controller   
      |   `-- MyController.php  
      `-- Service         
          `-- MyStringService.php
  </code></pre>
  
  <p>Now I want to use the service "MyStringService" in "MyController" like this:</p>
  
  <pre><code>&lt;?php
  
  namespace AppBundle\Controller;
  
  use Symfony\Component\Routing\Annotation\Route;
  use Symfony\Bundle\FrameworkBundle\Controller\Controller;
  use Symfony\Component\HttpFoundation\Request;
  use Symfony\Component\Validator\Constraints\Date;
  use Symfony\Component\VarDumper\Cloner\Data;
  
  class MyController extends Controller 
  {
      public function usernameAction(Request $request, $username)
      {
          $data = $this-&gt;get('my_string_service')-&gt;getString($username);
          return $this-&gt;render('profile.html.twig', $data);
      }
  }
  </code></pre>
  
  <p>So let's look at the service, that does basically nothing:</p>
  
  <pre><code>&lt;?php
  
  namespace AppBundle\Service;
  
  class MyStringService 
  {
  
      public function getString($string)
      {
          return $string;
      }
  
  }
  </code></pre>
  
  <p>And so that I can call it by the ID I have following in my services.yml:</p>
  
  <pre><code>services:
      my_string_service:
          class: AppBundle/Service/MyStringService
  </code></pre>
  
  <p>When I use <code>php bin/console debug:container my_string_service</code> I get:</p>
  
  <pre><code>Information for Service "my_string_service"
  ===========================================
  
   ---------------- ----------------------------------- 
    Option           Value
  ---------------- ----------------------------------- 
    Service ID       my_string_service                  
    Class            AppBundle/Service/MyStringService  
    Tags             -                                  
    Public           no                                 
    Synthetic        no                                 
    Lazy             no                                 
    Shared           yes                                
    Abstract         no
    Autowired        yes                                
    Autoconfigured   yes
  ---------------- ----------------------------------- 
  </code></pre>
  
  <p>Now when I start the service and open the page <code>localhost:8000/</code> or <code>localhost:8000/MyUsername</code> I get an <code>ServiceNotFoundException</code>.</p>
  
  <p>So now I just started with symfony and do not know what I am missing.</p>
  
  <p>Thanks in Advance</p>