1. import java.awt.*;
2. import java.awt.event.*;
3. import javax.swing.*;
4. 
5. public class SnakeGame extends JFrame implements ActionListener {
6. 
7. private static final long serialVersionUID = 1L;
8. 
9. // 定义游戏区域的大小
10. private final int WIDTH = 640;
11. private final int HEIGHT = 640;
12. 
13. // 定义贪吃蛇的初始位置和大小
14. private final int DOT_SIZE = 10;
15. private final int ALL_DOTS = 900;
16. private final int RAND_POS = 40;
17. private int[] x = new int[ALL_DOTS];
18. private int[] y = new int[ALL_DOTS];
19. private int dots;
20. private int apple_x;
21. private int apple_y;
22. 
23. // 定义贪吃蛇的移动方向
24. private boolean leftDirection = false;
25. private boolean rightDirection = true;
26. private boolean upDirection = false;
27. private boolean downDirection = false;
28. 
29. // 定义游戏是否结束
30. private boolean inGame = true;
31. 
32. // 定义计时器
33. private Timer timer;
34. 
35. public SnakeGame() {
36.         initGame();
37.         addKeyListener(new KeyAdapter() {
38. @Override
39. public void keyPressed(KeyEvent e) {
40. int key = e.getKeyCode();
41. if (key == KeyEvent.VK_LEFT && !rightDirection) {
42.                     leftDirection = true;
43.                     upDirection = false;
44.                     downDirection = false;
45.                 } else if (key == KeyEvent.VK_RIGHT && !leftDirection) {
46.                     rightDirection = true;
47.                     upDirection = false;
48.                     downDirection = false;
49.                 } else if (key == KeyEvent.VK_UP && !downDirection) {
50.                     upDirection = true;
51.                     leftDirection = false;
52.                     rightDirection = false;
53.                 } else if (key == KeyEvent.VK_DOWN && !upDirection) {
54.                     downDirection = true;
55.                     leftDirection = false;
56.                     rightDirection = false;
57.                 }
58.             }
59.         });
60.         setFocusable(true);
61.     }
62. 
63. public void initGame() {
64. // 初始化游戏区域
65.         setTitle("SnakeGame");
66.         setSize(WIDTH, HEIGHT);
67.         setResizable(false);
68.         setDefaultCloseOperation(EXIT_ON_CLOSE);
69.         setVisible(true);
70.         getContentPane().setBackground(Color.black);
71. // 初始化贪吃蛇的位置和大小
72.         dots = 3;
73. for (int i = 0; i < dots; i++) {
74.             x[i] = 50 - i * DOT_SIZE;
75.             y[i] = 50;
76.         }
77. 
78. // 初始化苹果的位置
79.         locateApple();
80. 
81. // 初始化计时器
82.         timer = new Timer(140, this);
83.         timer.start();
84.     }
85. 
86. public void locateApple() {
87. // 随机生成苹果的位置
88. int r = (int) (Math.random() * RAND_POS);
89.         apple_x = r * DOT_SIZE;
90. 
91.         r = (int) (Math.random() * RAND_POS);
92.         apple_y = r * DOT_SIZE;
93.     }
94. 
95. public void checkApple() {
96. // 检查贪吃蛇是否吃到了苹果
97. if ((x[0] == apple_x) && (y[0] == apple_y)) {
98.             dots++;
99.             locateApple();
100.         }
101.     }
102. 
103. public void checkCollision() {
104. // 检查贪吃蛇是否碰到了边界或自己的身体
105. for (int i = dots; i > 0; i--) {
106. if ((i > 4) && (x[0] == x[i]) && (y[0] == y[i])) {
107.                 inGame = false;
108.             }
109.         }
110. 
111. if (y[0] >= HEIGHT) {
112.             inGame = false;
113.         }
114. 
115. if (y[0] < 0) {
116.             inGame = false;
117.         }
118. 
119. if (x[0] >= WIDTH) {
120.             inGame = false;
121.         }
122. 
123. if (x[0] < 0) {
124.             inGame = false;
125.         }
126. 
127. if (!inGame) {
128.             timer.stop();
129.         }
130.     }
131. 
132. public void move() {
133. // 移动贪吃蛇
134. for (int i = dots; i > 0; i--) {
135.             x[i] = x[(i - 1)];
136.             y[i] = y[(i - 1)];
137.         }
138. 
139. if (leftDirection) {
140.             x[0] -= DOT_SIZE;
141.         }
142. 
143. if (rightDirection) {
144.             x[0] += DOT_SIZE;
145.         }
146. 
147. if (upDirection) {
148.             y[0] -= DOT_SIZE;
149.         }
150. 
151. if (downDirection) {
152.             y[0] += DOT_SIZE;
153.         }
154.     }
155. 
156. public void actionPerformed(ActionEvent e) {
157. // 计时器触发事件
158. if (inGame) {
159.             checkApple();
160.             checkCollision();
161.             move();
162.             repaint(); // 重绘游戏区域
163.         }
164.     }
165. 
166. public void paint(Graphics g) {
167. 
168. // 绘制游戏区域
169. super.paint(g);
170.         g.setColor(Color.black);
171. 
172. if (inGame) {
173.             g.setColor(Color.red);
174.             g.fillOval(apple_x, apple_y, DOT_SIZE, DOT_SIZE);
175. 
176. for (int i = 0; i < dots; i++) {
177.                 g.setColor(Color.green);
178.                 g.fillRect(x[i], y[i], DOT_SIZE, DOT_SIZE);
179.             }
180. 
181.             Toolkit.getDefaultToolkit().sync();
182.         } else {
183.             gameOver(g);
184.         }
185.     }
186. 
187. public void gameOver(Graphics g) {
188. // 游戏结束
189. String msg = "GAME OVER";
190. Font small = new Font("Helvetica", Font.BOLD, 40);
191. FontMetrics metr = getFontMetrics(small);
192. 
193.         g.setColor(Color.white);
194.         g.setFont(small);
195.         g.drawString(msg, (WIDTH - metr.stringWidth(msg)) / 2, HEIGHT / 2);
196.     }
197. 
198. 
199. public static void main(String[] args) {
200. new SnakeGame();
201.     }
202. }