On an azerty keyboard, when I press the key "!", the code of the key returned by KeyEvent is "Undefined".

The "!" key is just on left of the right "shift" key. (see http://en.wikipedia.org/wiki/File:KB_France.svg )

Snippet :

public class KeyboardCodeViewer
    extends Application
{

	public static void main(
	    final String[] args)

	{
		KeyboardCodeViewer.launch(args);
	}

	private TextArea textArea;

	private Label label;

	@Override
	public void start(
	    final Stage primaryStage)
	    throws Exception
	{
		VBox root = new VBox();

		label = new Label("Coucou");
		label.setPrefSize(300d, 300d);
		label.setFocusTraversable(true);
		label.setOnKeyPressed(new EventHandler<KeyEvent>() {

			@Override
			public void handle(
			    final KeyEvent event)
			{
				textArea.appendText(event.getCode().getName() + " : " + event.getCode().impl_getCode() + '\n');
			}
		});
		textArea = new TextArea();
		textArea.setPrefSize(300d, 300d);

		root.getChildren().add(label);
		root.getChildren().add(textArea);

		primaryStage.setScene(new Scene(root));
		primaryStage.sizeToScene();
		primaryStage.centerOnScreen();
		primaryStage.show();

	}
}

Start and then press a key, you should see the name and key code. But when you press "!", you'll get "Undefined"