package com.baosight.apssc.mp.js.service;
import java.awt.*;
import java.awt.event.*;
import java.util.Random;
import javax.swing.*;
public class SnakeGame extends JPanel implements ActionListener {
private final int WIDTH = 300;
private final int HEIGHT = 300;
private final int UNIT_SIZE = 10;
private final int GAME_UNITS = (WIDTH * HEIGHT) / UNIT_SIZE;
private 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 SnakeGame() {
random = new Random();
this.setPreferredSize(new Dimension(WIDTH, HEIGHT));
this.setBackground(Color.black);
this.setFocusable(true);
this.addKeyListener(new MyKeyAdapter());
startGame();
}
public void startGame() {
newApple();
running = true;
timer = new Timer(DELAY, this);
timer.start();
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
draw(g);
}
public void draw(Graphics g) {
if (running) {
// Draw the apple
g.setColor(Color.red);
g.fillOval(appleX, appleY, UNIT_SIZE, UNIT_SIZE);
// Draw the snake
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);
}
// Draw the score
g.setColor(Color.white);
g.setFont(new Font("Ink Free", Font.BOLD, 20));
FontMetrics metrics = getFontMetrics(g.getFont());
g.drawString("Score: " + applesEaten, (WIDTH - metrics.stringWidth("Score: " + applesEaten)) / 2, g.getFont().getSize());
} else {
gameOver(g);
}
}
public void newApple() {
appleX = random.nextInt((int) (WIDTH / UNIT_SIZE)) * UNIT_SIZE;
appleY = random.nextInt((int) (HEIGHT / UNIT_SIZE)) * UNIT_SIZE;
}
public 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;
}
}
public void checkApple() {
if ((x[0] == appleX) && (y[0] == appleY)) {
bodyParts++;
applesEaten++;
newApple();
}
}
public void checkCollisions() {
// Check if head collides with body
for (int i = bodyParts; i > 0;
i--) {
if ((x[0] == x[i]) && (y[0] == y[i])) {
running = false;
break;
}
}
// Check if head touches left border
if (x[0] < 0) {
running = false;
}
// Check if head touches right border
if (x[0] > WIDTH) {
running = false;
}
// Check if head touches top border
if (y[0] < 0) {
running = false;
}
// Check if head touches bottom border
if (y[0] > HEIGHT) {
running = false;
}
if (!running) {
timer.stop();
}
}
public void gameOver(Graphics g) {
// Draw the score
g.setColor(Color.white);
g.setFont(new Font("Ink Free", Font.BOLD, 40));
FontMetrics metrics1 = getFontMetrics(g.getFont());
g.drawString("Score: " + applesEaten, (WIDTH - metrics1.stringWidth("Score: " + applesEaten)) / 2, g.getFont().getSize());
// Draw the game over message
g.setColor(Color.red);
g.setFont(new Font("Ink Free", Font.BOLD, 75));
FontMetrics metrics2 = getFontMetrics(g.getFont());
g.drawString("Game Over", (WIDTH - metrics2.stringWidth("Game Over")) / 2, HEIGHT / 2);
}
@Override
public void actionPerformed(ActionEvent e) {
if (running) {
move();
checkApple();
checkCollisions();
}
repaint();
}
public 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 Game");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(400, 400);
frame.add(new SnakeGame());
frame.setVisible(true);
}
}
此代码使用Java Swing库和AWT事件处理程序创建了一个贪吃蛇游戏。游戏由一个主要的SnakeGame类组成，该类扩展了JPanel并实现了ActionListener接口来处理定时器事件。在主要类中，定义了一些实例变量，如贪吃蛇的长度、方向、苹果的位置等。在构造函数中，创建了一个Random实例，并设置了面板的首选大小和背景色，并启动游戏。游戏循环是在startGame()方法中开始的，该方法创建一个定时器并启动它，以触发ActionListener事件。在每个游戏循环中，move()方法将贪吃蛇的位置向前移动一个单位，并检查贪吃蛇是否吃到了苹果，如果吃到了苹果，它会调用checkApple()方法并增加贪吃蛇的长度和得分。checkCollisions()方法用于检查贪吃蛇是否与自身或边界相撞。如果是，游戏将结束。如果游戏结束，gameOver()方法将在面板上显示得分和游戏结束消息。最后，MyKeyAdapter类是一个嵌套的内部类，用于监听用户输入，并在按下方向键时更新贪吃蛇的方向。
Q.E.D.