JavaFx:无法创建播放器

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.layout.StackPane;
import javafx.scene.media.Media;
import javafx.scene.media.MediaPlayer;
import javafx.scene.media.MediaView;
import javafx.stage.Stage;

public class VideoPlayer extends Application {
    public static void main(String[] args) {
        launch(args);
    }

    @Override
    public void start(Stage primaryStage) {
        String videoPath = "path/to/video.mp4"; // 视频文件路径

        Media media = new Media(videoPath);
        MediaPlayer mediaPlayer = new MediaPlayer(media);
        MediaView mediaView = new MediaView(mediaPlayer);

        StackPane root = new StackPane();
        root.getChildren().add(mediaView);

        Scene scene = new Scene(root, 800, 600);
        primaryStage.setScene(scene);
        primaryStage.show();

        mediaPlayer.play(); // 播放视频
    }
}