1、采用MVC（model、view、control）框架模式

3、包和类的关系树形图为：

4、源码：

 package com.huai;import java.awt.Color;
import java.awt.Graphics;
import java.awt.Point;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.Set;import com.huai.listener.SnakeListener;
import com.huai.util.Constant;public class Snake {//和蛇的监听器有关Set<SnakeListener> snakeListener = new HashSet<SnakeListener>();//用链表保存蛇的身体节点LinkedList<Point> body = new LinkedList<Point>();private boolean life = true;//默认速度为400msprivate int speed = 400;private Point lastTail = null;private boolean pause = false;//定义各个方向public static final int UP = 1;public static final int DOWN = -1;public static final int LEFT = 2;public static final int RIGHT = -2;int newDirection = RIGHT;int oldDirection = newDirection;public Snake(){initial();}public void initial(){//先清空所有的节点body.removeAll(body);int x = Constant.WIDTH/2;int y = Constant.HEIGHT/2;//蛇的默认长度为7for(int i = 0; i < 7; i++){body.add(new Point(x--, y));}}public void setSpeed(int speed){this.speed = speed;}public void setLife(boolean life){this.life = life;}public boolean getLife(){return this.life;}public boolean getPause(){return this.pause;}public void setPause(boolean pause){this.pause = pause;}public void move(){//蛇移动的实现所采用的数据结构为：蛇尾删除一个节点，蛇头增加一个节点。System.out.println("snake move");if(!(oldDirection + newDirection == 0)){oldDirection = newDirection;}lastTail = body.removeLast();int x = body.getFirst().x;int y = body.getFirst().y;switch(oldDirection){case UP:y--;break;case DOWN:y++;break;case LEFT:x--;break;case RIGHT:x++;break;}Point point = new Point(x, y);body.addFirst(point);}//当吃到一个食物的时候，把删掉的蛇尾节点增加回来public void eatFood(){System.out.println("snake eat food");body.addLast(lastTail);}public boolean isEatItself(){for(int i = 2; i < body.size(); i++){if(body.getFirst().equals(body.get(i))){return true;}}return false;}public void drawMe(Graphics g){System.out.println("draw snake");//循环打印蛇的各个身体节点for(Point p:body){if(p.equals(body.getFirst())){//当是蛇头的时候，就设置颜色为橘色g.setColor(Color.orange);}else{g.setColor(Color.pink);}g.fill3DRect(p.x * Constant.CELL_SIZE, p.y * Constant.CELL_SIZE, Constant.CELL_SIZE, Constant.CELL_SIZE, true);}}public void changeDirection(int direction){System.out.println("snake changeDirection");this.newDirection = direction;}//内部类，新增一个游戏线程public class DriveSnake implements Runnable{  @Overridepublic void run() {while(life){if(!pause){//只要让蛇不动就可以暂停游戏move();}//监听蛇每次移动的情况for(SnakeListener listener : snakeListener){listener.snakeMove(Snake.this);}try {Thread.sleep(speed);} catch (InterruptedException e) {e.printStackTrace();}}}}public void startMove(){new Thread(new DriveSnake()).start();}//增加监听器的方法public void addSnakeListener(SnakeListener listener){if(listener != null){snakeListener.add(listener);}}//返回蛇的第一个身体节点public Point getHead(){return body.getFirst();}//返回蛇的所有身体节点public LinkedList<Point> getSnakeBody(){return this.body;}public boolean died(){this.life = false;return true;}
}

package com.huai;import java.awt.Color;
import java.awt.Graphics;
import java.awt.Point;import com.huai.util.Constant;public class Food {private int x = 0;private int y = 0;//设置食物的默认颜色为红色private Color color = Color.red;public void newFood(Point point){x = point.x;y = point.y;}//判断是否被吃到public boolean isAte(Snake snake){if(snake.getHead().equals(new Point(x, y))){System.out.println("food isAte");return true;}return false;}public void setFoodColor(Color color){this.color = color;}public Color getFoodColor(){return this.color;}public void drawMe(Graphics g){System.out.println("draw food");g.setColor(this.getFoodColor());g.fill3DRect(x * Constant.CELL_SIZE, y * Constant.CELL_SIZE,Constant.CELL_SIZE, Constant.CELL_SIZE, true);}
}

package com.huai;import java.awt.Color;
import java.awt.Graphics;
import java.awt.Point;
import java.util.LinkedList;
import java.util.Random;import com.huai.util.Constant;public class Ground {//在二维数组中，当为1，表示是砖块private int[][] rock = new int[Constant.WIDTH][Constant.HEIGHT];private boolean drawLine = true;public boolean isDrawLine() {return drawLine;}public void setDrawLine(boolean drawLine) {this.drawLine = drawLine;} public Ground(){for(int x = 0; x < Constant.WIDTH; x++){for(int y = 0; y < Constant.HEIGHT; y++){rock[0][y] = 1;rock[x][0] = 1;rock[Constant.WIDTH-1][y] = 1;rock[y][Constant.HEIGHT-1] = 1;}}}//打印游戏的网格public void drawGrid(Graphics g){for(int x = 2; x < Constant.WIDTH; x++){g.drawLine(x * Constant.CELL_SIZE, 0, x*Constant.CELL_SIZE,Constant.CELL_SIZE * Constant.HEIGHT);}for(int y = 2; y < Constant.HEIGHT; y++){g.drawLine(0, y * Constant.CELL_SIZE, Constant.WIDTH*Constant.CELL_SIZE, y*Constant.CELL_SIZE);}}public void drawMe(Graphics g){System.out.println("draw ground");//打印围墙g.setColor(Color.pink);for(int x = 0; x < Constant.WIDTH; x++){for(int y = 0; y < Constant.HEIGHT; y++){if(rock[x][y] == 1){g.fill3DRect(x * Constant.WIDTH, y * Constant.HEIGHT,Constant.CELL_SIZE, Constant.CELL_SIZE, true);}}}if(isDrawLine()){g.setColor(Color.yellow);this.drawGrid(g);}}//得到一个随机点public Point getRandomPoint(Snake snake, Thorn thorn){Random random = new Random();boolean isUnderSnakebody = false;boolean isUnderThorn = false;int x,y = 0;LinkedList<Point> snakeBody = snake.getSnakeBody();LinkedList<Point> thorns = thorn.getThorns();do{x = random.nextInt(Constant.WIDTH);y = random.nextInt(Constant.HEIGHT);for(Point p:snakeBody){if(x == p.x && y == p.y){isUnderSnakebody = true;}}for(Point point : thorns){if(x == point.x && y == point.y){isUnderThorn = true;}}}while(rock[x][y] == 1 && !isUnderSnakebody && !isUnderThorn);return new Point(x, y);}public boolean isSnakeHitRock(Snake snake){System.out.println("snack hit rock");for(int i = 0; i < Constant.WIDTH; i++){for(int j = 0; j < Constant.HEIGHT; j++){if(snake.getHead().x == i && snake.getHead().y == j && rock[i][j] == 1){return true;}}}return false;}}

 package com.huai;import java.awt.Color;
import java.awt.Graphics;
import java.awt.Point;
import java.util.LinkedList;import com.huai.util.Constant;public class Thorn {  int x, y;private LinkedList<Point> thorns = new LinkedList<Point>();//返回所有荆棘的链表public LinkedList<Point> getThorns(){return this.thorns;}public void newThorn(Point point){x = point.x;y = point.y;thorns.add(new Point(x, y));}public void drawMe(Graphics g){System.out.println("draw thorns");for(Point p: thorns){int[] xb = {p.x*Constant.CELL_SIZE, (p.x*Constant.CELL_SIZE +Constant.CELL_SIZE/2),(p.x*Constant.CELL_SIZE+Constant.CELL_SIZE),(p.x*Constant.CELL_SIZE+Constant.CELL_SIZE/4*3), (p.x*Constant.CELL_SIZE+Constant.CELL_SIZE),(p.x*Constant.CELL_SIZE+Constant.CELL_SIZE/2), p.x*Constant.CELL_SIZE,(p.x*Constant.CELL_SIZE+Constant.CELL_SIZE/4), p.x*Constant.CELL_SIZE};int [] yb = {p.y*Constant.CELL_SIZE, (p.y*Constant.CELL_SIZE+Constant.CELL_SIZE/4),p.y*Constant.CELL_SIZE,(p.y*Constant.CELL_SIZE+Constant.CELL_SIZE/2),(p.y*Constant.CELL_SIZE+Constant.CELL_SIZE),(int)(p.y*Constant.CELL_SIZE+Constant.CELL_SIZE*0.75),(p.y*Constant.CELL_SIZE+Constant.CELL_SIZE),(p.y*Constant.CELL_SIZE+Constant.CELL_SIZE/2),p.y*Constant.CELL_SIZE};g.setColor(Color.darkGray);g.fillPolygon(xb, yb, 8);}}public boolean isSnakeHitThorn(Snake snake){for(Point points : thorns){if(snake.getHead().equals(points)){System.out.println("hit thorn");return true;}}return false;}}

 package com.huai.listener;import com.huai.Snake;public interface SnakeListener {public void snakeMove(Snake snake);
}

 package com.huai.util;public class Constant {public static int CELL_SIZE = 20;public static int WIDTH = 20;public static int HEIGHT = 20;
}

 package com.huai.view;import java.awt.Color;
import java.awt.Graphics;import javax.swing.JPanel;import com.huai.Food;
import com.huai.Ground;
import com.huai.Snake;
import com.huai.Thorn;
import com.huai.util.Constant;public class GamePanel extends JPanel{/*** */private static final long serialVersionUID = 1L;Snake snake;Food food;Ground ground;Thorn thorn;public void display(Snake snake, Food food, Ground ground, Thorn thorn){this.snake = snake;this.food = food;this.ground = ground;this.thorn = thorn;System.out.println("display gamePanel");this.repaint();}@Overrideprotected void paintComponent(Graphics g) {if(snake != null && food != null && ground != null){g.setColor(Color.lightGray);g.fillRect(0, 0, Constant.WIDTH*Constant.CELL_SIZE, Constant.HEIGHT*Constant.CELL_SIZE);snake.drawMe(g);food.drawMe(g);ground.drawMe(g);thorn.drawMe(g);}else{System.out.println("snake = null || food = null || ground = null");}}
}

 package com.huai.controller;import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;import com.huai.Food;
import com.huai.Ground;
import com.huai.Snake;
import com.huai.Thorn;
import com.huai.listener.SnakeListener;
import com.huai.view.GamePanel;public class Controller extends KeyAdapter implements SnakeListener{
/*** 整个游戏的控制类，属于MVC设计框架中的Controller* 其中包括控制游戏的监听事件和游戏逻辑*/Snake snake;Food food;Ground ground;GamePanel gamePanel;Thorn thorn;public Controller(){}//利用构造方法初始化对象public Controller(Snake snake, Food food, Ground ground, GamePanel gamePanel, Thorn thorn) {super();this.snake = snake;this.food = food;this.ground = ground;this.gamePanel = gamePanel;this.thorn = thorn;}@Overridepublic void keyPressed(KeyEvent e) {switch(e.getKeyCode()){case KeyEvent.VK_UP:snake.changeDirection(Snake.UP);snake.setSpeed(150);break;case KeyEvent.VK_DOWN:snake.changeDirection(Snake.DOWN);snake.setSpeed(150);break;case KeyEvent.VK_LEFT:snake.changeDirection(Snake.LEFT);snake.setSpeed(150);break;case KeyEvent.VK_RIGHT:snake.changeDirection(Snake.RIGHT);snake.setSpeed(150);break;case KeyEvent.VK_ENTER:if(!snake.getPause() && snake.getLife()){//暂停游戏snake.setPause(true);;}else if(!snake.getLife()){//重新开始游戏snake.setLife(true);snake.initial();snake.changeDirection(Snake.UP);thorn.getThorns().removeAll(thorn.getThorns());this.startGame();}else{snake.setPause(false);}break;case KeyEvent.VK_L://当按下L按钮时，是否显示游戏网格if(ground.isDrawLine()){ground.setDrawLine(false);}else{ground.setDrawLine(true);}break;}}@Overridepublic void keyReleased(KeyEvent e) {switch(e.getKeyCode()){case KeyEvent.VK_UP:snake.setSpeed(400);break;case KeyEvent.VK_DOWN:snake.setSpeed(400);break;case KeyEvent.VK_LEFT:snake.setSpeed(400);break;case KeyEvent.VK_RIGHT:snake.setSpeed(400);break;}}//这是实现SnakeListener监听器所Override的方法@Overridepublic void snakeMove(Snake snake) {//显示snake ，food，ground，和thorngamePanel.display(snake, food, ground, thorn);if(ground.isSnakeHitRock(snake)){snake.died();}if(snake.isEatItself()){snake.died();}if(food.isAte(snake)){snake.eatFood();food.newFood(ground.getRandomPoint(snake, thorn));thorn.newThorn(ground.getRandomPoint(snake, thorn));}if(thorn.isSnakeHitThorn(snake)){snake.died();}}public void startGame(){snake.startMove();//这个将会启动一个新的线程food.newFood(ground.getRandomPoint(snake, thorn));thorn.newThorn(ground.getRandomPoint(snake, thorn));}}

 package com.huai.game;import java.awt.BorderLayout;
import java.awt.Color;import javax.swing.JFrame;
import javax.swing.JLabel;import com.huai.Food;
import com.huai.Ground;
import com.huai.Snake;
import com.huai.Thorn;
import com.huai.controller.Controller;
import com.huai.util.Constant;
import com.huai.view.GamePanel;public class Game {public static void main(String args[]){Snake snake = new Snake();Food food = new Food();GamePanel  gamePanel = new GamePanel();Ground ground = new Ground();Thorn thorn = new Thorn();Controller controller = new Controller(snake, food, ground, gamePanel, thorn);JFrame frame = new JFrame("怀哥的小小蛇儿游戏");frame.add(gamePanel);frame.setBackground(Color.magenta);frame.setSize(Constant.WIDTH*Constant.CELL_SIZE+6, Constant.HEIGHT*Constant.CELL_SIZE+40);gamePanel.setSize(Constant.WIDTH*Constant.CELL_SIZE, Constant.HEIGHT*Constant.CELL_SIZE);frame.add(gamePanel);frame.setResizable(false);//不可改变窗口大小frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);frame.setVisible(true);gamePanel.addKeyListener(controller);snake.addSnakeListener(controller);frame.addKeyListener(controller);JLabel label1 = new JLabel();label1.setBounds(0, 400, 400, 100);label1.setText("                  ENTER=>>PAUSE or AGAIN;          "+ " L=>DRAWGRID");label1.setForeground(Color.BLACK);frame.add(label1, BorderLayout.SOUTH);controller.startGame();}
}