贪吃蛇逻辑代码

package cd.itcast.snake;

import java.awt.BorderLayout;
import java.awt.Point;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.util.LinkedList;
import java.util.Random;

import javax.swing.JButton;
import javax.swing.JFrame;

import cn.itcast.util.FrameUtil;



public class SnakeGame {
    //宽度（列数）x
    public static final int WIDTH = 50;
    //高度（行数）y
    public static final int HEIGHT = 10;
    //地图
    private char[][] background = new char[HEIGHT][WIDTH];
    
    //初始化地图
    private void initBackground() {
        for(int rows = 0 ; rows < background.length ; rows++){
            for(int cols = 0 ; cols < background[rows].length ; cols++){
                if (rows==0||rows==(background.length-1)) {
                    background[rows][cols]='*';
                }else {
                    background[rows][cols]=' ';
                }
            }
        }
    }
    //显示地图的
        private void showBackground() {
            for(int rows = 0 ; rows < background.length ; rows++){
                for(int cols = 0 ; cols < background[rows].length ; cols++){
                    System.out.print(background[rows][cols]);
                }
                System.out.println();
            }
        }
    //使用集合保存蛇所有信息
    LinkedList<Point> snake = new LinkedList<Point>();
    //初始化蛇
    public void initsnake() {
        int x = WIDTH/2;
        int y = HEIGHT/2;
        snake.addFirst(new Point(x-1,y));
        snake.addFirst(new Point(x,y));
        snake.addFirst(new Point(x+1,y));
    }
    //显示蛇--》蛇的节点信息，反馈到地图上
    public void showSnake() {
        //画蛇身,因为取出了蛇身，所以从1开始
        for(int i=1; i<snake.size();i++){
            Point body = snake.get(i);
            background[body.y][body.x] = '#'; 
        }
        //画蛇头,注意和二维数组对应
        Point head = snake.getFirst();
        background[head.y][head.x] = '$';
    }
    //蛇移动:向上移动
    public static final int UP_DIRECTION = 1;
    public static final int DOWN_DIRECTION = -1;
    public static final int LEFT_DIRECTION = 2;
    public static final int RIGHT_DIRECTION = -2;
    //默认方向
    int currentDecration=-2;
    //蛇移动的方法
    public void move() {
        Point head = snake.getFirst();
        //根据当前方向移动
        switch (currentDecration) {
        case UP_DIRECTION:
            snake.addFirst(new Point(head.x, head.y-1));
            break;
        case DOWN_DIRECTION:
            snake.addFirst(new Point(head.x, head.y+1));
            break;
        case LEFT_DIRECTION:
            //穿越左边
            if(head.x==0){
                snake.addFirst(new Point(WIDTH-1, head.y));
            }else {
                snake.addFirst(new Point(head.x-1, head.y));
            }
            break;
        case RIGHT_DIRECTION:
            if(head.x==WIDTH-1){
                snake.addFirst(new Point(0, head.y));
            }else {
                snake.addFirst(new Point(head.x+1, head.y));
            }
            break;
        default:
            break;
        }
        //如果吃到了，就要创建新的食物；没吃到才删除
        if (snakeEat()) {
            createFood();
        }else {
            snake.removeLast();
        }
        
    }
    //改变方向的方法
    public void changeDirection(int newDirection) {
        if(newDirection + currentDecration!=0){
            this.currentDecration = newDirection;
        }
    }
    //食物
    Point food;
    //创建食物
    public void createFood() {
        Random random = new Random();
        while (true) {
            int x = random.nextInt(WIDTH);
            int y = random.nextInt(HEIGHT);
            if(background[y][x]!='*'){
                food = new Point(x,y);
                break;
            }
        }
    }
    //显示食物
    public void showFood() {
        background[food.y][food.x] = '&';
    }
    //吃食物:在移动的时候调用，因为每走一步，都可能吃到；当吃到的时候，蛇尾不删除
    public boolean snakeEat() {
        Point head = snake.getFirst();
        if(head.equals(food)){
            return true;
        }
        return false;
    }
    //刷新
    public void refrash() {
        //清空全部信息
        initBackground();
        //把食物的最新信息反馈到地图上
        showFood();
        //把蛇的最新信息反馈到地图上
        showSnake();
        //显示当前地图的信息
        showBackground();
    }
    //游戏是否结束
    static boolean isGameOver = false;
    public void isGameOver() {
        Point head = snake.getFirst();
        //撞墙死
        if (background[head.y][head.x]=='*') {
            isGameOver = true;
        }
        //咬死自己
        for(int i=1; i<snake.size(); i++){
            Point body = snake.get(i);
            if(head.equals(body)){
                isGameOver = true;
            }
        }
    }
    public static void main(String[] args) throws InterruptedException {
        final SnakeGame snake = new SnakeGame();
        //初始化地图
        snake.initBackground();
        //初始化蛇
        snake.initsnake();
        //显示蛇
        snake.showSnake();
        //初始化食物
        snake.createFood();
        //显示食物
        snake.showFood();
        snake.showBackground();
        JFrame frame = new JFrame("方向盘");
        frame.add(new JButton("↑"),BorderLayout.NORTH);
        frame.add(new JButton("↓"),BorderLayout.SOUTH);
        frame.add(new JButton("←"),BorderLayout.WEST);
        frame.add(new JButton("→"),BorderLayout.EAST);
        JButton button = new JButton("点我控制方向");
        frame.add(button);
        FrameUtil.initFrame(frame, 300, 300);
        //添加事件监听器
        button.addKeyListener(new KeyAdapter() {
            @Override
            public void keyPressed(KeyEvent e) {
                int code = e.getKeyCode();
                switch (code) {
                    case KeyEvent.VK_UP:
                        snake.changeDirection(UP_DIRECTION);
                        break;
                    case KeyEvent.VK_DOWN:
                        snake.changeDirection(DOWN_DIRECTION);
                        break;
                    case KeyEvent.VK_LEFT:
                        snake.changeDirection(LEFT_DIRECTION);
                        break;
                    case KeyEvent.VK_RIGHT:
                        snake.changeDirection(RIGHT_DIRECTION);
                        break;
                    default:
                        break;
                }
                snake.move();
                snake.isGameOver();
                if(isGameOver){
                    System.err.println("游戏结束！！！");
                    System.exit(0);
                }
                snake.refrash();
            }
        });
    }
}