After creating a FXML file and clicking on "Make Controller", a class is generated that implements Initializable and overrides its initialize method.

This approach is obsolete in JavaFX 2.2+ and the class should _not_ implement Initializable and the generated method could have the following signature: @FXML private void initialize() {}

This might be an issue for older versions of JavaFX though.

Reference: http://docs.oracle.com/javafx/2/fxml_get_started/whats_new2.htm