JavaFX open new window

I use the following method in my JavaFX applications.

newWindowButton.setOnMouseClicked((event) -> {
    try {
        FXMLLoader fxmlLoader = new FXMLLoader();
        fxmlLoader.setLocation(getClass().getResource("NewWindow.fxml"));
        /* 
         * if "fx:controller" is not set in fxml
         * fxmlLoader.setController(NewWindowController);
         */
        Scene scene = new Scene(fxmlLoader.load(), 600, 400);
        Stage stage = new Stage();
        stage.setTitle("New Window");
        stage.setScene(scene);
        stage.show();
    } catch (IOException e) {
        Logger logger = Logger.getLogger(getClass().getName());
        logger.log(Level.SEVERE, "Failed to create new Window.", e);
    }
});

If you just want a button to open up a new window, then something like this works:

btnOpenNewWindow.setOnAction(new EventHandler<ActionEvent>() {
    public void handle(ActionEvent event) {
        Parent root;
        try {
            root = FXMLLoader.load(getClass().getClassLoader().getResource("path/to/other/view.fxml"), resources);
            Stage stage = new Stage();
            stage.setTitle("My New Stage Title");
            stage.setScene(new Scene(root, 450, 450));
            stage.show();
            // Hide this current window (if this is what you want)
            ((Node)(event.getSource())).getScene().getWindow().hide();
        }
        catch (IOException e) {
            e.printStackTrace();
        }
    }
}

The code below worked for me I used part of the code above inside the button class.

public Button signupB;

public void handleButtonClick (){

    try {
        FXMLLoader fxmlLoader = new FXMLLoader();
        fxmlLoader.setLocation(getClass().getResource("sceneNotAvailable.fxml"));
        /*
         * if "fx:controller" is not set in fxml
         * fxmlLoader.setController(NewWindowController);
         */
        Scene scene = new Scene(fxmlLoader.load(), 630, 400);
        Stage stage = new Stage();
        stage.setTitle("New Window");
        stage.setScene(scene);
        stage.show();
    } catch (IOException e) {
        Logger logger = Logger.getLogger(getClass().getName());
        logger.log(Level.SEVERE, "Failed to create new Window.", e);
    }

}

}