带有EventHandler的Javafx按钮。获取无法找到符号错误

Question

我想点击一下按钮打印出 Java很有趣，当我运行它时，我一直收到找不到符号错误。我不确定它是我的import语句还是代码本身的实际错误。我想知道是否有人可以帮我弄清楚为什么我会收到错误？

import javafx.application.Application;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.Pane;
import javafx.stage.Stage;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;


public class ButtonHandler extends Application {
    @Override // Override the start method in the Application class
  public void start(Stage primaryStage) {

    Pane pane = new Pane();

    Button btOK = new Button("OK");
    pane.getChildren().add(btOK);

    btOK.setOnAction((ActionEvent e) -> {
      System.out.println("Java is Fun");
    });

    // Create a scene and place it in the stage
    Scene scene = new Scene(Pane);
    primaryStage.setTitle("Button Demo"); // Set title
    primaryStage.setScene(scene); // Place the scene in the stage
    primaryStage.show(); // Display the stage
}

  public static void main(String[] args) {
    launch(args);
  }
}