title: Spring MVC Model Attribute null
body: <p>I want do add an ID to a URL in my template:</p>
  
  <pre><code>@Controller
  public class DashboardController {
  
      @RequestMapping("/dashboard")
      public String index(Model model){
  
          model.addAttribute("provider_id", "1");
  
          return "dashboard";
      }
  }
  </code></pre>
  
  <p>In my dashboard.html I want do display the ID.</p>
  
  <pre><code>&lt;a th:href="@{'/cloudservice/' + ${provider_id}}"&gt;Show&lt;/a&gt;
  </code></pre>
  
  <p>But the Generated URL is <code>/cloudservice/null</code>. Why isn't the 1 displayed that i put into the model?</p>