HelloWorld with JavaFX
Here is the HelloWorld JavaFX application that shows the Hello, World! and Exit text:
import javafx.application.Application;
import javafx.application.Platform;
import javafx.scene.control.Button;
import javafx.scene.layout.Pane;
import javafx.scene.text.Text;
import javafx.scene.Scene;
import javafx.stage.Stage;
public class HelloWorld extends Application {
  public static void main(String... args) {
      launch(args);
  }
  @Override
  public void start(Stage primaryStage) {
    Text txt = new Text("Hello, world!");
    txt.relocate(135, 40);
    Button btn = new Button("Exit");
    btn.relocate(155, 80);
    btn.setOnAction(e:> {
        System.out.println("Bye! See...
