项目结构

1. 新建一个JFrame窗口,作为程序入口

public class GameStart{

    public static void main(String[] args) {

        JFrame jFrame = new JFrame();

        jFrame.setBounds(100,100,900,720);

        jFrame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

        jFrame.setResizable(false);

        jFrame.add(new GameJPanel());

        jFrame.setVisible(true);

    }

}

1. 创建一个面板类

//面板

public class GameJPanel extends JPanel implements ActionListener {

    int length;//蛇的长度

    int[] snakeX = new int[600];//蛇的X的最大长度

    int[] snakeY = new int[500];//蛇的Y的最大长度

    String fx = "R";

    boolean isStart = false;//默认不开始

    //定时器

    Timer timer = new Timer(100, this);//100毫秒=1秒

    int foodX;

    int foodY;

    Random random = new Random();//随机数

    boolean isFail = false;//失败条件

    int score;

    public GameJPanel() {

        init();

        this.setFocusable(true);//获取焦点事件

        addKeyListener(new GameKeyListener(this));

        //开启定时器

        timer.start();

    }

    //初始化

    void init() {

        length = 3;

        snakeX[0] = 100;

        snakeY[0] = 100;//第一个身体

        snakeX[1] = 75;

        snakeY[1] = 100;//第二个身体

        snakeX[2] = 50;

        snakeY[2] = 100;//第三个身体

        fx = "R";

        //食物随机分布

        foodX = 25 + 25 * random.nextInt(34);

        foodY = 75 + 25 * random.nextInt(24);

        score = 0;

    }

    //绘制面板,所有东西都是通过graphics这个画笔绘制

    @Override

    protected void paintComponent(Graphics graphics) {

        super.paintComponent(graphics);//清屏

        //添加静态布局

        GameData.header.paintIcon(this, graphics, 25, 11);

        graphics.fillRect(25, 75, 850, 600);

        //积分板

        graphics.setColor(Color.white);

        graphics.setFont(new Font("微软雅黑", Font.BOLD, 18));

        graphics.drawString("长度："+length,750,35);

        graphics.drawString("得分："+score,750,55);

        //先画食物，防止吃掉有延迟

        GameData.food.paintIcon(this, graphics, foodX, foodY);

        //画小蛇

        switch (fx) {

            case "R":

                GameData.right.paintIcon(this, graphics, snakeX[0], snakeY[0]);

                break;

            case "L":

                GameData.left.paintIcon(this, graphics, snakeX[0], snakeY[0]);

                break;

            case "U":

                GameData.up.paintIcon(this, graphics, snakeX[0], snakeY[0]);

                break;

            case "D":

                GameData.down.paintIcon(this, graphics, snakeX[0], snakeY[0]);

                break;

        }

        //身体

        for (int i = 1; i < length; i++) {

            GameData.body.paintIcon(this, graphics, snakeX[i], snakeY[i]);

        }

        //游戏状态

        if (!isStart) {

            graphics.setColor(Color.white);

            graphics.setFont(new Font("微软雅黑", Font.BOLD, 40));//设置字体

            graphics.drawString("按下空格，开始游戏", 300, 300);

        }

        //游戏失败

        if (isFail) {

            graphics.setColor(Color.red);

            graphics.setFont(new Font("微软雅黑", Font.BOLD, 40));

            graphics.drawString("游戏失败,请按空格继续", 300, 300);

        }

    }

    //事件监听--固定事件刷新一次，1s=100ms

    @Override

    public void actionPerformed(ActionEvent actionEvent) {

        if (isStart && !isFail) {

            //吃食物

            if (snakeX[0] == foodX && snakeY[0] == foodY) {

                //长度+1

                length++;

                score+=10;

                //重新随机绘制食物

                foodX = 25 + 25 * random.nextInt(34);

                foodY = 75 + 25 * random.nextInt(24);

            }

            //后一节移动到前一节，从而由头带动身体移动

            for (int i = length - 1; i > 0; i--) {

                snakeX[i] = snakeX[i - 1];

                snakeY[i] = snakeY[i - 1];

            }

            switch (fx) {

                case "R":

                    snakeX[0] += 25;//头部移动

                    // 边界判断

                    if (snakeX[0] > 850) { snakeX[0] = 25; }

                    break;

                case "L":

                    snakeX[0] -= 25;//头部移动

                    if (snakeX[0] < 25) { snakeX[0] = 850; }

                    break;

                case "U":

                    snakeY[0] -= 25;//头部移动

                    if (snakeY[0] < 75) { snakeY[0] = 650; }

                    break;

                case "D":

                    snakeY[0] += 25;//头部移动

                    if (snakeY[0] > 650) { snakeY[0] = 75; }

                    break;

            }

            //失败判定

            for (int i = 1; i < length; i++) {

                if (snakeX[0] == snakeX[i] && snakeY[0] == snakeY[i]) {

                    isFail = true;

                    break;

                }

            }

            repaint();//重绘

        }

        //开启定时器

        timer.start();

    }

}

所有组件添加流程基本一致，即先定义数据，然后在画笔paintComponent方法中绘制，最后添加到监听事件。

完整代码请参考：

GitHub完整贪吃蛇小游戏链接