java实现贪吃蛇游戏

闲来无事，整理以前的代码，发现了这个小游戏，所以就想记录下来。贪吃蛇，大家童年的游戏吧。

黑色：贪吃蛇主题 红色：食物左上角：分数

 

整个游戏由四个类组成

1.Dir.java(枚举类，记录了贪吃蛇移动的方向)

public enum Dir {
	L,U,R,D
}

2.Egg.java

public class Egg {
	
	int row,col;
	int w = Yard.BLOCK_SIZE;
	int h = Yard.BLOCK_SIZE;
	// 产生随机数，显示位置
	private static Random r = new Random();        
	private Color color = Color.GREEN;
	
	public Egg(int row, int col) {
		this.row = row;
		this.col = col;
	}
	
	// 随机显示鸡蛋位置
	public Egg() {
		this(r.nextInt(Yard.ROWS-2) + 2,r.nextInt(Yard.COLS));
		
	}
	
	public void reAppear() {
		this.row = r.nextInt(Yard.ROWS-2) + 2;
		this.col = r.nextInt(Yard.COLS);
	}
	
	public Rectangle getRect() {
		return new Rectangle(Yard.BLOCK_SIZE * col, Yard.BLOCK_SIZE * row, w, h);
	}
	
	public void draw(Graphics g){
		Color c = g.getColor();
		g.setColor(color);
		// 填充外接指定矩形框的椭圆
		g.fillOval(Yard.BLOCK_SIZE * col, Yard.BLOCK_SIZE * row, w, h);  
		g.setColor(c);
		if(color == Color.GREEN) color = Color.RED;
		else color = Color.GREEN;
	}
	
	public int getRow() {
		return row;
	}

	public void setRow(int row) {
		this.row = row;
	}

	public int getCol() {
		return col;
	}

	public void setCol(int col) {
		this.col = col;
	}
}

3.Snake.java(贪吃蛇类，基本对象，保存贪吃蛇的状态)

public class Snake {
	
	private Node head = null;
	private Node tail = null;
	private int size = 0;
	
	private Node n = new Node(20, 30, Dir.L);
	private Yard y;
	
	public Snake(Yard y) {
		head = n;
		tail = n;
		size = 1;
		this.y = y;
	}
	
	public void addToTail() {
		Node node = null;
		switch(tail.dir) {
		case L :
			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 R :
			node = new Node(tail.row, tail.col - 1, 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 ++;
	}
	
	public void addToHead() {
		Node node = null;
		switch(head.dir) {
		case L :
			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 R :
			node = new Node(head.row, head.col + 1, 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 ++;
	}
	
	public void draw(Graphics g) {
		if(size <= 0) return;
		move();
		for(Node n = head; n != null; n = n.next) {
			n.draw(g);
		}	
	}
	
 	private void move() {
		addToHead();
		deleteFromTail();
		checkDead();
	}

	private void checkDead() {
		if(head.row < 2 || head.col < 0 || head.row > Yard.ROWS || head.col > Yard.COLS) {
			y.stop();
		}
		
		for(Node n = head.next; n != null; n=n.next){
			if(head.row == n.row && head.col == n.col) {
				y.stop();
			}
		}
		
	}

	//移动时尾部一节删掉
	private void deleteFromTail() {
		if(size == 0) return;
		tail = tail.prev;
		tail.next = null;
	}

	/*
	 * 定义一个类来实现贪吃蛇的连接移动
	 * 因为java中没有链表，所以借助类来实现
	 */
	private class Node {
		int w = Yard.BLOCK_SIZE;
		int h = Yard.BLOCK_SIZE;
		int row , col;
		Dir dir = Dir.L;
		Node next = null;
		Node prev = null;
		
		Node(int row, int col, Dir dir) {
			this.row = row;
			this.col = col;
			this.dir = dir;
		}
		
		void draw(Graphics g) {
			Color c = g.getColor();
			g.setColor(Color.BLACK);
			g.fillRect(Yard.BLOCK_SIZE * col, Yard.BLOCK_SIZE * row, w, h);
			g.setColor(c);
		}
	}
	
	// 增加分数
	public void eat(Egg e) {
		if(this.getRect().intersects(e.getRect())) {
			e.reAppear();
			this.addToHead();
			y.setScore(y.getScore() + 5);
		}
	}
	
	private Rectangle getRect() {
		return new Rectangle(Yard.BLOCK_SIZE * head.col, Yard.BLOCK_SIZE * head.row, head.w, head.h);
	}
	
	// 监听按键状态
	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_UP :
			if(head.dir != Dir.D)
				head.dir = Dir.U;
			break;
		case KeyEvent.VK_RIGHT :
			if(head.dir != Dir.L)	
				head.dir = Dir.R;
			break;
		case KeyEvent.VK_DOWN :
			if(head.dir != Dir.U)
				head.dir = Dir.D;
			break;
		}	
	}
}

4.Yard.java(主体类，实现控制整个程序)

public class Yard extends Frame {

	PaintThread paintThread = new PaintThread();
	private boolean gameOver = false;
	
	public static final int ROWS = 30;
	public static final int COLS = 30;
	public static final int BLOCK_SIZE = 15;
	
	private Font fontGameOver = new Font("宋体", Font.BOLD, 50);
	private int score = 0;
	
	Snake s = new Snake(this);
	Egg e = new Egg();
	Image offScreenImage = null;
	
	public int getScore() {
		return score;
	}
    public void setScore(int score) {
		this.score = score;
	}
	
	public void launch() {
		this.setLocation(200, 200);
		this.setSize(COLS * BLOCK_SIZE, ROWS * BLOCK_SIZE);
		
		//使退出键有效果
		this.addWindowListener(new WindowAdapter() {
			public void windowClosing(WindowEvent e) {
				System.exit(0);
			}
		});
		this.setVisible(true);
		this.addKeyListener(new KeyMonitor());
		new Thread(paintThread).start();
	}
	
	public static void main(String[] args) {
		new  Yard().launch();
	}
	
	public void stop() {
		gameOver = true;
	}
	
	public void paint(Graphics g) {
		Color c = g.getColor();
		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=1; i

上述代码不难，感兴趣的朋友应该很容易就理解，本人在eclipse可以运行。