编写贪吃蛇小游戏，使用JAVA语言，用IntelliJ IDEA软件编写

好的，以下是一个简单的贪吃蛇小游戏的Java代码，你可以在IntelliJ IDEA中创建一个Java项目，将代码复制到Main.java文件中，然后运行该文件来启动游戏。

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

public class Main extends JPanel implements ActionListener {

    private static final int SCREEN_WIDTH = 600;
    private static final int SCREEN_HEIGHT = 600;
    private static final int UNIT_SIZE = 25;
    private static final int GAME_UNITS = (SCREEN_WIDTH * SCREEN_HEIGHT) / UNIT_SIZE;
    private static final int DELAY = 75;

    private final int[] x = new int[GAME_UNITS];
    private final int[] y = new int[GAME_UNITS];
    private int bodyParts = 6;
    private int applesEaten;
    private int appleX;
    private int appleY;
    private char direction = 'R';
    private boolean running = false;
    private Timer timer;
    private Random random;

    public Main() {
        random = new Random();
        setPreferredSize(new Dimension(SCREEN_WIDTH, SCREEN_HEIGHT));
        setBackground(Color.BLACK);
        setFocusable(true);
        addKeyListener(new MyKeyAdapter());
        startGame();
    }

    private void startGame() {
        newApple();
        running = true;
        timer = new Timer(DELAY, this);
        timer.start();
    }

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

    private void draw(Graphics g) {
        if (running) {
            g.setColor(Color.RED);
            g.fillOval(appleX, appleY, UNIT_SIZE, UNIT_SIZE);

            for (int i = 0; i < bodyParts; i++) {
                if (i == 0) {
                    g.setColor(Color.GREEN);
                } else {
                    g.setColor(new Color(45, 180, 0));
                }
                g.fillRect(x[i], y[i], UNIT_SIZE, UNIT_SIZE);
            }
            g.setColor(Color.RED);
            g.setFont(new Font("Ink Free", Font.BOLD, 40));
            FontMetrics metrics = getFontMetrics(g.getFont());
            g.drawString("Score: " + applesEaten, (SCREEN_WIDTH - metrics.stringWidth("Score: " + applesEaten)) / 2, g.getFont().getSize());
        } else {
            gameOver(g);
        }
    }

    private void newApple() {
        appleX = random.nextInt((int) (SCREEN_WIDTH / UNIT_SIZE)) * UNIT_SIZE;
        appleY = random.nextInt((int) (SCREEN_HEIGHT / UNIT_SIZE)) * UNIT_SIZE;
    }

    private void move() {
        for (int i = bodyParts; i > 0; i--) {
            x[i] = x[i - 1];
            y[i] = y[i - 1];
        }
        switch (direction) {
            case 'U':
                y[0] = y[0] - UNIT_SIZE;
                break;
            case 'D':
                y[0] = y[0] + UNIT_SIZE;
                break;
            case 'L':
                x[0] = x[0] - UNIT_SIZE;
                break;
            case 'R':
                x[0] = x[0] + UNIT_SIZE;
                break;
        }
    }

    private void checkApple() {
        if ((x[0] == appleX) && (y[0] == appleY)) {
            bodyParts++;
            applesEaten++;
            newApple();
        }
    }

    private void checkCollisions() {
        for (int i = bodyParts; i > 0; i--) {
            if ((x[0] == x[i]) && (y[0] == y[i])) {
                running = false;
            }
        }
        if (x[0] < 0) {
            running = false;
        }
        if (x[0] > SCREEN_WIDTH) {
            running = false;
        }
        if (y[0] < 0) {
            running = false;
        }
        if (y[0] > SCREEN_HEIGHT) {
            running = false;
        }
        if (!running) {
            timer.stop();
        }
    }

    private void gameOver(Graphics g) {
        g.setColor(Color.RED);
        g.setFont(new Font("Ink Free", Font.BOLD, 75));
        FontMetrics metrics = getFontMetrics(g.getFont());
        g.drawString("Game Over", (SCREEN_WIDTH - metrics.stringWidth("Game Over")) / 2, SCREEN_HEIGHT / 2);
        g.setColor(Color.RED);
        g.setFont(new Font("Ink Free", Font.BOLD, 40));
        metrics = getFontMetrics(g.getFont());
        g.drawString("Score: " + applesEaten, (SCREEN_WIDTH - metrics.stringWidth("Score: " + applesEaten)) / 2, g.getFont().getSize());
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        if (running) {
            move();
            checkApple();
            checkCollisions();
        }
        repaint();
    }

    private class MyKeyAdapter extends KeyAdapter {
        @Override
        public void keyPressed(KeyEvent e) {
            switch (e.getKeyCode()) {
                case KeyEvent.VK_LEFT:
                    if (direction != 'R') {
                        direction = 'L';
                    }
                    break;
                case KeyEvent.VK_RIGHT:
                    if (direction != 'L') {
                        direction = 'R';
                    }
                    break;
                case KeyEvent.VK_UP:
                    if (direction != 'D') {
                        direction = 'U';
                    }
                    break;
                case KeyEvent.VK_DOWN:
                    if (direction != 'U') {
                        direction = 'D';
                    }
                    break;
            }
        }
    }

    public static void main(String[] args) {
        JFrame frame = new JFrame("Snake");
        frame.setContentPane(new Main());
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }
}

这段代码使用Java Swing库来创建游戏窗口，并使用键盘监听器来处理用户输入。该游戏使用一个定时器来不断更新贪吃蛇的位置，检查是否吃到苹果或者撞到边界或自己身体，最后在游戏结束时显示得分和Game Over的信息。