title: No result in TableView
body: <p>I have problem with show one column in <strong>TableView</strong>. I get data with JSON.
  Query:</p>
  
  <pre><code>[{"idmarks":3,"idusers":1,"mark":8.0,"test":{"date":"2016-01-01T12:34:59+01:00","idtests":2,"title":"test 2"}},{"idmarks":4,"idusers":1,"mark":4.0,"test":{"date":"2014-01-01T11:11:11+01:00","idtests":3,"title":"test 111"}}]
  </code></pre>
  
  <p>Code:</p>
  
  <pre><code>@FXML
  private void action(){
      ObjectMapper mapper = new ObjectMapper();
      List&lt;Marks&gt; lista = null;
      String path = "http://localhost:8080/Server/source/users/1/marks";
      try {
          lista = mapper.readValue(new URL(path), new TypeReference&lt;List&lt;Marks&gt;&gt;(){});
      } catch (IOException ex) {
          System.out.println(ex);
      }
  
      ObservableList&lt;Marks&gt; lis = FXCollections.observableArrayList(lista);
      table.setItems(lis);
  
      TableColumn&lt;Marks, String&gt; first = new TableColumn&lt;Marks,String&gt;("Mark");
      first.setCellValueFactory(new PropertyValueFactory("mark"));
      TableColumn&lt;Marks,String&gt; second = new TableColumn&lt;Marks,String&gt;("Title");
      second.setCellValueFactory(new PropertyValueFactory("title"));
  
      table.getColumns().setAll(first, second);  
  }
  </code></pre>
  
  <p><a href="http://pastebin.com/AadPQ4KS" rel="nofollow noreferrer">Marks.java</a></p>
  
  <p>and score:</p>
  
  <p><a href="https://i.stack.imgur.com/TKp3c.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/TKp3c.jpg" alt="TableView"></a></p>