public void start(Stage primaryStage) {
    primaryStage.setTitle("MenuBar2Example");
    Pane root = new Pane();
    Scene scene = new Scene(root, 300, 250);

    final MenuBar menuBar = new MenuBar();
    label = new Label();
    fileMenu = new Menu("File");
    newMenuItem = new MenuItem("New");
    showMenuItem = new MenuItem("Show Text");
    exitMenuItem = new MenuItem("Exit");

    fileMenu.getItems().addAll(newMenuItem, showMenuItem, exitMenuItem);

    //exitMenuItem.setOnAction(actionEvent -> Platform.exit());
    menuBar.getMenus().add(fileMenu);
    menuBar.prefWidthProperty().bind(primaryStage.widthProperty());
    attachCode(newMenuItem, showMenuItem, exitMenuItem);
    root.getChildren().addAll(menuBar);
    root.getChildren().add(label);

    primaryStage.setScene(scene);
    primaryStage.show();
}