import javafx.application.Application; import javafx.stage.Stage; import javafx.scene.Scene; import javafx.scene.control.Button; import javafx.scene.layout.StackPane; public class App extends Application { public static void main(String[] args) { launch(args); } @Override public void start(Stage stage) { Button button = new Button("Mehet"); button.setOnAction(e -> onButtonClick()); StackPane root = new StackPane(); root.getChildren().add(button); Scene scene = new Scene(root, 300, 250); stage.setScene(scene); stage.setTitle("Valami"); stage.show(); } private void onButtonClick() { System.out.println("Kattintás volt"); } }