Boîte de message dans Javafx

Alert alert = new Alert(AlertType.INFORMATION);
alert.setTitle("Message Here...");
alert.setHeaderText("Look, an Information Dialog");
alert.setContentText("I have a great message for you!");
alert.showAndWait().ifPresent(rs -> {
    if (rs == ButtonType.OK) {
        System.out.println("Pressed OK.");
    }
});
Unusual Unicorn