title: JavaFX: Run ChangeListener
body: <p>Ho can I run the change method inside <code>ChangeListener</code> in the initialization.
  Since it only run when changes happen. For example I have a <code>TextField</code> that I want to set it's value to 0 when it's empty, and I do it like this:</p>
  
  <pre><code>textField.textProperty().addListener(new ChangeListener&lt;String&gt;() {
          @Override
          public void changed(ObservableValue&lt;? extends String&gt; observable, String oldValue, String newValue) {
              if (!newValue.matches("\\d*")) {
                  textField.setText(newValue.replaceAll("[^\\d]", ""));
              }
  
              if (newValue.isEmpty())
                  textField.setText("0");
  
          }
      });
  </code></pre>
  
  <p>But at the start of the application the changed method is not called. So how to work around this issue?</p>