请给出javafx中贪吃蛇代码

下面是一个简单的 JavaFX 贪吃蛇游戏示例代码：

import javafx.animation.KeyFrame;
import javafx.animation.Timeline;
import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.canvas.Canvas;
import javafx.scene.canvas.GraphicsContext;
import javafx.scene.input.KeyCode;
import javafx.scene.paint.Color;
import javafx.stage.Stage;
import javafx.util.Duration;

public class SnakeGame extends Application {

    private static final int BLOCK_SIZE = 10;
    private static final int WIDTH = 400;
    private static final int HEIGHT = 400;

    private int direction = KeyCode.RIGHT.getCode();
    private boolean gameOver = false;
    private Timeline timeline = new Timeline();
    private Canvas canvas = new Canvas(WIDTH, HEIGHT);

    private int foodX = (int) (Math.random() * (WIDTH / BLOCK_SIZE)) * BLOCK_SIZE;
    private int foodY = (int) (Math.random() * (HEIGHT / BLOCK_SIZE)) * BLOCK_SIZE;
    private int snakeLength = 3;
    private int[] snakeX = new int[WIDTH * HEIGHT / BLOCK_SIZE / BLOCK_SIZE];
    private int[] snakeY = new int[WIDTH * HEIGHT / BLOCK_SIZE / BLOCK_SIZE];

    @Override
    public void start(Stage primaryStage) {
        Group root = new Group();
        root.getChildren().add(canvas);
        Scene scene = new Scene(root);
        scene.setOnKeyPressed(event -> {
            if (event.getCode().isArrowKey() && Math.abs(direction - event.getCode().getCode()) != 2) {
                direction = event.getCode().getCode();
            }
        });
        primaryStage.setScene(scene);
        primaryStage.show();

        timeline.setCycleCount(Timeline.INDEFINITE);
        timeline.getKeyFrames().add(new KeyFrame(Duration.millis(100), event -> {
            if (gameOver) {
                timeline.stop();
                return;
            }

            GraphicsContext gc = canvas.getGraphicsContext2D();
            gc.setFill(Color.BLACK);
            gc.fillRect(0, 0, WIDTH, HEIGHT);

            gc.setFill(Color.RED);
            gc.fillRect(foodX, foodY, BLOCK_SIZE, BLOCK_SIZE);

            int dx = 0, dy = 0;
            switch (direction) {
                case KeyCode.LEFT:
                    dx = -BLOCK_SIZE;
                    break;
                case KeyCode.RIGHT:
                    dx = BLOCK_SIZE;
                    break;
                case KeyCode.UP:
                    dy = -BLOCK_SIZE;
                    break;
                case KeyCode.DOWN:
                    dy = BLOCK_SIZE;
                    break;
            }

            int headX = snakeX[0] + dx;
            int headY = snakeY[0] + dy;
            if (headX < 0 || headX >= WIDTH || headY < 0 || headY >= HEIGHT) {
                gameOver = true;
                return;
            }
            for (int i = 1; i < snakeLength; i++) {
                if (headX == snakeX[i] && headY == snakeY[i]) {
                    gameOver = true;
                    return;
                }
            }

            if (headX == foodX && headY == foodY) {
                foodX = (int) (Math.random() * (WIDTH / BLOCK_SIZE)) * BLOCK_SIZE;
                foodY = (int) (Math.random() * (HEIGHT / BLOCK_SIZE)) * BLOCK_SIZE;
                snakeLength++;
            }

            for (int i = snakeLength - 1; i > 0; i--) {
                snakeX[i] = snakeX[i - 1];
                snakeY[i] = snakeY[i - 1];
            }
            snakeX[0] = headX;
            snakeY[0] = headY;

            gc.setFill(Color.LIME);
            for (int i = 0; i < snakeLength; i++) {
                gc.fillRect(snakeX[i], snakeY[i], BLOCK_SIZE, BLOCK_SIZE);
            }
        }));
        timeline.play();

        snakeX[0] = WIDTH / 2;
        snakeY[0] = HEIGHT / 2;
    }

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

该代码基于 JavaFX 平台，使用了画布(Canvas)实现游戏的绘制和键盘事件处理。游戏中的蛇是由一个数组表示的，每个数组元素代表蛇的一个身体部分的坐标。游戏循环使用 Timeline 实现，每个循环周期绘制一次游戏画面。在游戏画面绘制过程中，会根据玩家按键的方向更新蛇的位置，同时判断蛇是否吃到了食物，蛇是否碰到了墙壁或者自己的身体，以决定游戏是否结束。