javafx resizable window

1scene.widthProperty().addListener(new ChangeListener<Number>() {
2    @Override public void changed(ObservableValue<? extends Number> observableValue, Number oldSceneWidth, Number newSceneWidth) {
3        System.out.println("Width: " + newSceneWidth);
4    }
5});
6scene.heightProperty().addListener(new ChangeListener<Number>() {
7    @Override public void changed(ObservableValue<? extends Number> observableValue, Number oldSceneHeight, Number newSceneHeight) {
8        System.out.println("Height: " + newSceneHeight);
9    }
10});