利用java写一个贪吃蛇游戏并具有暂停功能

好的，以下是一个简单的贪吃蛇游戏的Java代码，同时也实现了暂停功能。你可以参考一下：

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class SnakeGame extends JPanel implements ActionListener, KeyListener {
    private static final int WIDTH = 300;
    private static final int HEIGHT = 300;
    private static final int DOT_SIZE = 10;
    private static final int ALL_DOTS = 900;
    private static final int RAND_POS = 29;
    private static final int DELAY = 140;

    private int[] x = new int[ALL_DOTS];
    private int[] y = new int[ALL_DOTS];

    private int dots;
    private int apple_x;
    private int apple_y;

    private Timer timer;
    private boolean inGame = true;
    private boolean paused = false;

    private char direction = 'R';

    public SnakeGame() {
        addKeyListener(this);
        setBackground(Color.black);
        setPreferredSize(new Dimension(WIDTH, HEIGHT));

        setFocusable(true);
        initGame();
    }

    private void initGame() {
        dots = 3;

        for (int i = 0; i < dots; i++) {
            x[i] = 50 - i * DOT_SIZE;
            y[i] = 50;
        }

        locateApple();

        timer = new Timer(DELAY, this);
        timer.start();
    }

    @Override
    public void paintComponent(Graphics g) {
        super.paintComponent(g);

        doDrawing(g);
    }

    private void doDrawing(Graphics g) {
        if (inGame) {
            g.setColor(Color.red);
            g.fillOval(apple_x, apple_y, DOT_SIZE, DOT_SIZE);

            for (int i = 0; i < dots; i++) {
                if (i == 0) {
                    g.setColor(Color.green);
                } else {
                    g.setColor(Color.white);
                }

                g.fillRect(x[i], y[i], DOT_SIZE, DOT_SIZE);
            }

            Toolkit.getDefaultToolkit().sync();
        } else {
            gameOver(g);
        }
    }

    private void gameOver(Graphics g) {
        String msg = "Game Over";
        Font font = new Font("Helvetica", Font.BOLD, 14);
        FontMetrics metr = getFontMetrics(font);

        g.setColor(Color.white);
        g.setFont(font);
        g.drawString(msg, (WIDTH - metr.stringWidth(msg)) / 2, HEIGHT / 2);
    }

    private void checkApple() {
        if ((x[0] == apple_x) && (y[0] == apple_y)) {
            dots++;
            locateApple();
        }
    }

    private void move() {
        for (int i = dots; i > 0; i--) {
            x[i] = x[(i - 1)];
            y[i] = y[(i - 1)];
        }

        switch (direction) {
            case 'U':
                y[0] -= DOT_SIZE;
                break;
            case 'D':
                y[0] += DOT_SIZE;
                break;
            case 'L':
                x[0] -= DOT_SIZE;
                break;
            case 'R':
                x[0] += DOT_SIZE;
                break;
        }
    }

    private void checkCollision() {
        for (int i = dots; i > 0; i--) {
            if ((i > 4) && (x[0] == x[i]) && (y[0] == y[i])) {
                inGame = false;
            }
        }

        if (y[0] >= HEIGHT) {
            inGame = false;
        }

        if (y[0] < 0) {
            inGame = false;
        }

        if (x[0] >= WIDTH) {
            inGame = false;
        }

        if (x[0] < 0) {
            inGame = false;
        }

        if (!inGame) {
            timer.stop();
        }
    }

    private void locateApple() {
        int r = (int) (Math.random() * RAND_POS);
        apple_x = r * DOT_SIZE;

        r = (int) (Math.random() * RAND_POS);
        apple_y = r * DOT_SIZE;
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        if (!paused) {
            if (inGame) {
                checkApple();
                checkCollision();
                move();
            }

            repaint();
        }
    }

    @Override
    public void keyPressed(KeyEvent e) {
        int key = e.getKeyCode();

        if ((key == KeyEvent.VK_LEFT) && (direction != 'R')) {
            direction = 'L';
        }

        if ((key == KeyEvent.VK_RIGHT) && (direction != 'L')) {
            direction = 'R';
        }

        if ((key == KeyEvent.VK_UP) && (direction != 'D')) {
            direction = 'U';
        }

        if ((key == KeyEvent.VK_DOWN) && (direction != 'U')) {
            direction = 'D';
        }

        if (key == KeyEvent.VK_SPACE) {
            paused = !paused;
        }
    }

    @Override
    public void keyReleased(KeyEvent e) {
    }

    @Override
    public void keyTyped(KeyEvent e) {
    }

    public static void main(String[] args) {
        JFrame frame = new JFrame("Snake");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        SnakeGame game = new SnakeGame();
        frame.add(game);

        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }
}

在这个代码中，我们使用了Java的Swing库来绘制游戏窗口，并实现了贪吃蛇游戏的逻辑。同时，我们在keyPressed方法中检测了空格键，以实现暂停功能。