Example
To show some content in a new window, a Stage needs to be created. After creation and initialisation show or showAndWait needs to be called on the Stage object:
// create sample content
Rectangle rect = new Rectangle(100, 100, 200, 300);
Pane root = new Pane(rect);
root.setPrefSize(500, 500);
Parent content = root;
// create scene containing the content
Scene scene = new Scene(content);
Stage window = new Stage();
window.setScene(scene);
// make window visible
window.show();
Note: This code needs to be executed on the JavaFX application thread.
