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"