Java SE (Java Platform, Standard Edition)

I'm beginner with javaFX and i need to change language of the screen. but i have no idea how to reload the screen when the language was changed. The application have a button where have the language available. I want just refresh screen when the user change language.

Here is the start method to show the stage.

    @Override

    public void start(Stage stage) throws Exception

    {

        this.stage = stage;

        Locale locale = Locale.getDefault();

        ResourceBundle rb = ResourceBundle.getBundle("resources/Label",locale);

        loader = new FXMLLoader(getClass().getResource("FXMLDocument.fxml"),rb);

        root = (Parent)loader.load();

        FXMLDocumentController controller = (FXMLDocumentController) loader.getController();

        controller.setMain(this);

        scene = new Scene(root);

        stage.setScene(scene);

        stage.show();

    }

here is the function to change the language(in the same class with start function),the rb is the new ResourceBundle:

    public void refresh(ResourceBundle rb)

    {

          //change the language here

     }

1. I don't want to use the resourceBundle to get value in resource file and set label in scene one by one.like following:

this.btnLabel.setText(rb.getString(key.test));

...

2. I don't want to reload the scene,like following:

    public void refresh(ResourceBundle rb)

    {

         try

        {

            loader = new FXMLLoader(getClass().getResource("FXMLDocument.fxml"),rb);

            root = (Parent)loader.load();

            scene.setRoot(root);

            FXMLDocumentController controller = (FXMLDocumentController) loader.getController();

            controller.setMain(this);

        }

        catch(Exception err)

        {

            err.printStackTrace();

        }

    }

So do we have a solution to just set the resourceBundle and reload the scene easier?

Thanks and best regards!