public class Start {public static void main(String[] args) {new Yard().launch();}
}

import java.awt.Color;
import java.awt.Font;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Panel;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;/**** @author xcx* @time 2017年7月28日下午3:44:48*/
public class Yard extends Frame {//设置游戏结束字体Font goFont = new Font("宋体",Font.ITALIC|Font.BOLD,50);//游戏开始的线程PaintThread paintThread = new PaintThread();//游戏得分public static int score = 0;//判断蛇是否死掉private static boolean flag = true;//行数与列数public static final int ROWS = 30;public static final int COLS = 30;// 每个格子的边长public static final int BLOCK_SIZE = 15;//定义一条蛇，一个蛋Snake s = new Snake();Egg e = new Egg();// 加入双缓冲Image offScreenImage = null;public void launch() {setLayout(null);setLocation(200, 200);setSize(COLS * BLOCK_SIZE, ROWS * BLOCK_SIZE);setVisible(true);addWindowListener(new WindowAdapter() {@Overridepublic void windowClosing(WindowEvent arg0) {setVisible(true);System.exit(0);}});// 添加键盘控制事件addKeyListener(new KeyMonitor());// 运行线程
        paintThread.start();}@Overridepublic void paint(Graphics g) {// 保存画笔额颜色Color color = g.getColor();// 设置画笔的颜色
        g.setColor(Color.gray);g.fillRect(0, 0, COLS * BLOCK_SIZE, ROWS * BLOCK_SIZE);g.setColor(Color.DARK_GRAY);// 画出横线for (int i = 0; i < ROWS; i++) {g.drawLine(0, BLOCK_SIZE * i, BLOCK_SIZE * COLS, BLOCK_SIZE * i);}// 画出竖线for (int i = 0; i < ROWS; i++) {g.drawLine(BLOCK_SIZE * i, 0, BLOCK_SIZE * i, BLOCK_SIZE * ROWS);}g.setColor(Color.yellow);g.drawString("score"+score, 10, 60);if(flag == false){g.setFont(goFont);g.drawString("game over", 100, 180);paintThread.gameOver();}// 还原画笔的颜色
        g.setColor(color);s.eat(e);e.draw(g);s.draw(g);}@Overridepublic void update(Graphics g) {if (offScreenImage == null) {offScreenImage = this.createImage(COLS * BLOCK_SIZE, ROWS* BLOCK_SIZE);}Graphics gOff = offScreenImage.getGraphics();paint(gOff);g.drawImage(offScreenImage, 0, 0, null);}//停止public static void stop(){flag = false;}// 不断刷新界面private class PaintThread extends Thread {private boolean running = true;@Overridepublic void run() {while (running) {repaint();try {Thread.sleep(200);} catch (InterruptedException e) {e.printStackTrace();}}}public void gameOver(){running = false;}}//键盘监听事件private class KeyMonitor extends KeyAdapter {@Overridepublic void keyPressed(KeyEvent e) {s.keyPressed(e);}}
}

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Rectangle;
import java.awt.event.KeyEvent;/**** @author xcx* @time 2017年7月28日下午3:45:03*/
public class Snake {// 蛇的头结点和尾结点private Node head = null;private Node tail = null;private int size = 0;// 自己定义一个头private Node node = new Node(20, 30, Dir.L);public Snake() {head = node;tail = node;size = 1;}// 将一个结点添加到尾巴上public void addToTail() {Node node = null;switch (tail.dir) {case L:node = new Node(tail.row, tail.col + 1, tail.dir);break;case R:node = new Node(tail.row, tail.col - 1, tail.dir);break;case U:node = new Node(tail.row + 1, tail.col, tail.dir);break;case D:node = new Node(tail.row - 1, tail.col, tail.dir);break;}tail.next = node;node.prev = tail;tail = node;size++;}// 将一个结点添加到头上public void addToHead() {Node node = null;switch (head.dir) {case L:node = new Node(head.row, head.col - 1, head.dir);break;case R:node = new Node(head.row, head.col + 1, head.dir);break;case U:node = new Node(head.row - 1, head.col, head.dir);break;case D:node = new Node(head.row + 1, head.col, head.dir);break;}node.next = head;head.prev = node;head = node;size++;}// 从蛇的尾巴删除一个结点private void deleteFromTail() {if (size == 0)return;tail = tail.prev;tail.next = null;}// 将蛇画出public void draw(Graphics g) {if (size <= 0)return;move();for (Node node = head; node != null; node = node.next) {node.draw(g);}}// 蛇移动一下private void move() {addToHead();deleteFromTail();checkDead();}// 检查蛇是否死掉private void checkDead() {// 判断蛇是否撞在了墙上if (head.row < 0 || head.row > Yard.ROWS || head.col < 0|| head.col > Yard.COLS) {Yard.stop();}// 判断蛇是否撞在了自己的身上for (Node node = head.next; node != null; node = node.next) {if (this.getRect().intersects(node.getRect())) {Yard.stop();}}}// 键盘按下后蛇头方向改变public void keyPressed(KeyEvent e) {int key = e.getKeyCode();switch (key) {case KeyEvent.VK_LEFT:if (head.dir != Dir.R)head.dir = Dir.L;break;case KeyEvent.VK_RIGHT:if (head.dir != Dir.L)head.dir = Dir.R;break;case KeyEvent.VK_UP:if (head.dir != Dir.D)head.dir = Dir.U;break;case KeyEvent.VK_DOWN:if (head.dir != Dir.U)head.dir = Dir.D;break;}}// 蛇吃蛋public void eat(Egg e) {if (this.getRect().intersects(e.getRect())) {e.reAppear();addToTail();Yard.score += 5;}}// 判断蛇头所在的格子private Rectangle getRect() {return new Rectangle(Yard.BLOCK_SIZE * head.col, Yard.BLOCK_SIZE* head.row, head.w, head.h);}// 定义结点内部类private class Node {// 结点的高度与宽度int w = Yard.BLOCK_SIZE;int h = Yard.BLOCK_SIZE;// 所在的位置int row, col;// 结点的方向Dir dir = Dir.L;// 后一个结点Node next = null;// 前一个结点Node prev = null;Node(int row, int col, Dir dir) {this.row = row;this.col = col;this.dir = dir;}void draw(Graphics g) {Color color = g.getColor();g.setColor(Color.black);g.fillRect(Yard.BLOCK_SIZE * col, Yard.BLOCK_SIZE * row, w, h);g.setColor(color);}// 判断节点所在的格子private Rectangle getRect() {return new Rectangle(Yard.BLOCK_SIZE * col, Yard.BLOCK_SIZE * row,w, h);}}
}

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Rectangle;
import java.util.Random;/**** @author xcx* @time 2017年7月28日下午3:45:11*/
public class Egg {// 设置蛋的颜色Color color = Color.green;// 出现的坐标private int row, col;// 蛋的高与宽private int w = Yard.BLOCK_SIZE;private int h = Yard.BLOCK_SIZE;private static Random r = new Random();public Egg(int x, int y) {this.row = x;this.col = y;}public Egg() {this(r.nextInt(Yard.ROWS), r.nextInt(Yard.COLS));}public void reAppear() {        this.row = r.nextInt(Yard.ROWS) ;this.col = r.nextInt(Yard.COLS) ;}// 画出一个蛋public void draw(Graphics g) {Color c = g.getColor();g.setColor(color);g.fillOval(Yard.BLOCK_SIZE * row, Yard.BLOCK_SIZE * col, w, h);g.setColor(c);if (color == Color.green) {color = Color.red;} else {color = Color.green;}}// 得到蛋所在的格子public Rectangle getRect() {return new Rectangle(Yard.BLOCK_SIZE * row, Yard.BLOCK_SIZE * col, w, h);}
}

/****@author xcx *@time 2017年7月28日下午4:14:38*/
public enum Dir {L,R,U,D}