贪吃蛇项目（简单）

1.游戏规则

分为三个关卡，每个关卡需要吃掉15个食物，才可进入下一关。
当蛇头碰到自身时，游戏失败！
可随意穿墙，会从另一侧出来！

2.游戏操作

w：上
s：下
a：左
d：右
空格：暂停/继续

3.代码片段

1）GameWin（主入口）

package com;

import com.obj.BodyObj;
import com.obj.FoodObj;
import com.obj.HeadObj;
import com.utils.GameUtils;

import javax.swing.*;
import java.awt.*;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.util.ArrayList;
import java.util.List;


public class GameWin extends JFrame {
    //分数统计
    public static int score=0;
    //游戏状态 0.未开始  1.游戏中  2.暂停  3.失败  4.通关   5.失败后重新开始   6.下一关
    public static int state=0;
    /*//定义双缓存图片
    Image offScreenImage=null;*/
    //窗口宽高
    int winWidth=800;
    int winHight=600;
    //蛇头对象
    public HeadObj headObj=new HeadObj(GameUtils.rightImg,60,570,this);

    //蛇身集合
    public List<BodyObj> bodyObjList=new ArrayList<>();

    //食物对象
    public FoodObj foodObj=new FoodObj().getFood();

    //先
    public void launch(){
        //设置窗口是否可见
        this.setVisible(true);
        //设置窗口的大小
        this.setSize(winWidth,winHight);
        //设置窗口不可调大小
        this.setResizable(false);
        //设置窗口的位置在屏幕上居中
        this.setLocationRelativeTo(null);
        //设置窗口的标题
        this.setTitle("Jm养贪吃蛇");

        //蛇身体的初始化
        bodyObjList.add(new BodyObj(GameUtils.bodyImg,30,570,this));
        bodyObjList.add(new BodyObj(GameUtils.bodyImg,0,570,this));
        //键盘监听事件
        this.addKeyListener(new KeyAdapter() {
            @Override
            public void keyPressed(KeyEvent e) {
                if(e.getKeyCode()==KeyEvent.VK_SPACE){
                    switch (state){
                        //未开始
                        case 0:
                            state=1;
                            break;
                        //游戏中
                        case 1:
                            state=2;
                            repaint();
                            break;
                        //暂停中
                        case 2:
                            state=1;
                            break;
                        //失败了
                        case 3:
                            state=5;
                            break;
                        //通过当前关卡
                        case 4:
                            state=6;
                            break;
                        default:
                            break;
                    }
                }
            }
        });
        while (true){
            //游戏中调用repaint()
            if(state==1){
                repaint();
            }
            //失败重启
            if(state==5){
                state=0;
                resetGame();
            }
            //通过当前关卡
            if(state==6){
                if(GameUtils.level!=3)
                {
                    state=1;
                    GameUtils.level++;
                    resetGame();
                }else{
                    state=1;
                    GameUtils.level=1;
                    resetGame();
                }
            }
            try {
                //1s=1000ms
                Thread.sleep(200);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }

    //后
    @Override
    public void paint(Graphics gImage) {
        /*//初始化双缓存图片
        if(offScreenImage==null){
            offScreenImage=this.createImage(winWidth,winHight);
        }
        //获取双缓存图片的graphics对象
        Graphics gImage=offScreenImage.getGraphics();*/
        //设置背景颜色
        gImage.setColor(Color.GREEN);
        gImage.fillRect(0,0,winWidth,winHight);
        //网格线颜色
        gImage.setColor(Color.BLACK);
        //网格划线
        for(int i=0;i<=20;i++)
        {
            //左上角为原点，向右为x轴正向，向下为y轴正向
            //画横线
            gImage.drawLine(0,30*i,600,30*i);
            //画竖线
            gImage.drawLine(30*i,0,30*i,600);
        }
        //绘制蛇身
        for(int i=bodyObjList.size()-1;i>=0;i--){
            bodyObjList.get(i).paintSelf(gImage);
        }
        //绘制蛇头
        headObj.paintSelf(gImage);
        //绘制食物
        foodObj.paintSelf(gImage);
        //绘制关卡
        GameUtils.drawWord(gImage,"第"+GameUtils.level+"关",Color.ORANGE,40,640,260);
        //绘制分数
        GameUtils.drawWord(gImage,GameWin.score+"分",Color.red,40,650,320);
        //绘制提示语
        prompt(gImage);
        /*//将双缓存图片绘制到窗口中
        g.drawImage(offScreenImage,0,0,null);*/
    }

    //绘制提示音
    void prompt(Graphics g){
        //未开始
        if(state==0){
            g.setColor(Color.BLUE);
            g.fillRect(100,200,400,100);
            GameUtils.drawWord(g,"按下空格,游戏开始",Color.YELLOW,40,110,260);
        }
        //暂停
        if(state==2){
            g.setColor(Color.BLUE);
            g.fillRect(100,200,400,100);
            GameUtils.drawWord(g,"按下空格,游戏继续",Color.YELLOW,40,110,260);
        }
        //失败
        if(state==3){
            g.setColor(Color.BLUE);
            g.fillRect(100,200,400,150);
            GameUtils.drawWord(g,"很遗憾，游戏失败",Color.RED,40,110,260);
            GameUtils.drawWord(g,"按下空格,重新开始",Color.RED,40,110,320);
        }
        //通过
        if(state==4){
            g.setColor(Color.BLUE);
            if(GameUtils.level==3){
                g.fillRect(100,200,400,150);
                GameUtils.drawWord(g,"达成条件，游戏通关",Color.GREEN,40,110,260);
                GameUtils.drawWord(g,"按下空格,再玩一次",Color.GREEN,40,110,320);
            }else {
                g.fillRect(100,200,400,100);
                GameUtils.drawWord(g,"按下空格,进入下一关",Color.GREEN,40,110,260);
            }
        }
    }

    //游戏重置
    public void resetGame(){
        //分数重置
        score=0;
        //关闭当前窗口
        this.dispose();
        //开启新的窗口
        String[] args={};
        main(args);
    }

    //程序主入口
    public static void main(String[] args) {
        //创建窗口对象
        GameWin gameWin=new GameWin();
        //调用方法，设置窗口
        gameWin.launch();

    }
}

2）GameObj（游戏物品类）

package com.obj;

import com.GameWin;

import java.awt.*;

//物品类
public class GameObj {
    //图片
    Image img;
    //坐标
    int x;
    int y;
    //宽高
    int width = 30;
    int height = 30;
    //窗口类的引用
    GameWin frame;

    //setter 和 getter
    public Image getImg() {
        return img;
    }

    public void setImg(Image img) {
        this.img = img;
    }

    public int getX() {
        return x;
    }

    public void setX(int x) {
        this.x = x;
    }

    public int getY() {
        return y;
    }

    public void setY(int y) {
        this.y = y;
    }

    public int getWidth() {
        return width;
    }

    public void setWidth(int width) {
        this.width = width;
    }

    public int getHeight() {
        return height;
    }

    public void setHeight(int height) {
        this.height = height;
    }

    public GameWin getFrame() {
        return frame;
    }

    public void setFrame(GameWin frame) {
        this.frame = frame;
    }

    //无参构造
    public GameObj() {
    }

    //有参构造
    public GameObj(Image img, int x, int y, GameWin frame) {
        this.img = img;
        this.x = x;
        this.y = y;
        this.frame = frame;
    }

    //有参构造
    public GameObj(Image img, int x, int y, int width, int height, GameWin frame) {
        this.img = img;
        this.x = x;
        this.y = y;
        this.width = width;
        this.height = height;
        this.frame = frame;
    }

    public void paintSelf(Graphics g){
        g.drawImage(img,x,y,null);
    }
}

3）GameUtils（游戏工具类）

package com.utils;

import java.awt.*;

//工具类
public class GameUtils {

    //蛇头
    public static Image upImg = Toolkit.getDefaultToolkit().getImage("src/img/up.png");
    public static Image downImg = Toolkit.getDefaultToolkit().getImage("src/img/down.png");
    public static Image leftImg = Toolkit.getDefaultToolkit().getImage("src/img/left.png");
    public static Image rightImg = Toolkit.getDefaultToolkit().getImage("src/img/right.png");
    //蛇身
    public static Image bodyImg = Toolkit.getDefaultToolkit().getImage("src/img/body.png");
    //食物
    public static Image foodImg = Toolkit.getDefaultToolkit().getImage("src/img/food.png");
    //关卡
    public static int level=1;
    //绘制文字
    public static void drawWord(Graphics g,String str,Color color,int size,int x,int y){
        g.setColor(color);
        //设计字体显示效果 Font mf = new Font(String 字体，int 风格，int 字号);
        g.setFont(new Font("宋体",Font.BOLD,size));
        g.drawString(str,x,y);
    }
}

4）HeadObj（蛇头类）

package com.obj;
import com.GameWin;
import com.utils.GameUtils;

import java.awt.*;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;

//蛇头类
public class HeadObj extends GameObj{
    //方向 up down left right
    private String direction = "right";

    //setter 和 getter
    public String getDirection() {
        return direction;
    }
    public void setDirection(String direction) {
        this.direction = direction;
    }

    //构造方法
    public HeadObj() {
    }
    public HeadObj(Image img, int x, int y, GameWin frame) {
        super(img,x,y,frame);
        //键盘监听事件
        this.frame.addKeyListener(new KeyAdapter() {
            @Override
            public void keyPressed(KeyEvent e) {
                changeDirection(e);
            }
        });
    }

    //控制移动方向 -a:左（lft）   -d:右（right）    -w:上（up）    -s:下（down）
    public void changeDirection(KeyEvent e){
        switch (e.getKeyCode()){
            case KeyEvent.VK_A:
                //不能向相反的方向移动
                if(!"right".equals(direction)){
                    direction="left";
                    //改变蛇头方向图案
                    img= GameUtils.leftImg;
                }
                break;
            case KeyEvent.VK_D:
                if(!"left".equals(direction)){
                    direction="right";
                    //改变蛇头方向图案
                    img= GameUtils.rightImg;
                }
                break;
            case KeyEvent.VK_W:
                if(!"down".equals(direction)){
                    direction="up";
                    //改变蛇头方向图案
                    img= GameUtils.upImg;
                }
                break;
            case KeyEvent.VK_S:
                if(!"up".equals(direction)){
                    direction="down";
                    //改变蛇头方向图
                    // 案
                    img= GameUtils.downImg;
                }
                break;
            default:
                break;
        }
    }

    //蛇的移动
    public void move(){
        //蛇身移动
        for(int i=this.frame.bodyObjList.size()-1;i>=1;i--){
            this.frame.bodyObjList.get(i).x=this.frame.bodyObjList.get(i-1).x;
            this.frame.bodyObjList.get(i).y=this.frame.bodyObjList.get(i-1).y;
            //蛇头与身体碰撞
            if(this.x==this.frame.bodyObjList.get(i).x&&this.y==this.frame.bodyObjList.get(i).y){
                //失败
                GameWin.state=3;
            }
        }
        this.frame.bodyObjList.get(0).x=this.x;
        this.frame.bodyObjList.get(0).y=this.y;

        //蛇头移动
        switch (direction){
            case "up":
                y-=height;
                break;
            case "down":
                y+=height;
                break;
            case "left":
                x-=width;
                break;
            case "right":
                x+=width;
                break;
            default:
                break;
        }
    }
    @Override
    public void paintSelf(Graphics g) {
        super.paintSelf(g);
        Integer newX=null;
        Integer newY=null;
        //蛇吃食物
        FoodObj food=this.frame.foodObj;
        if(food.x==this.x&&food.y==this.y){
            //生成新的食物位置
            this.frame.foodObj=food.getFood();
            //获取最后一节身体
            BodyObj lastBody=this.frame.bodyObjList.get(this.frame.bodyObjList.size()-1);
            newX=lastBody.x;
            newY=lastBody.y;
            //增加长度
            GameWin.score++;
        }
        //通关判断
        if(GameWin.score>=15){
            //通过
            GameWin.state=4;
        }
        //移动蛇头
        move();
        //move结束之后，新的bodyObj对象添加到bodyObjList
        if(newX!=null&&newY!=null){
            this.frame.bodyObjList.add(new BodyObj(GameUtils.bodyImg,newX,newY,this.frame));
        }

        //越界处理
        if (x < 0){
            x = 570;
        } else if (x > 570){
            x = 0;
        } else if (y < 30){
            y = 570;
        }else if (y > 570){
            y = 30;
        }
    }
}

5）BodyObj（蛇身类）

package com.obj;

import com.GameWin;

import java.awt.*;

public class BodyObj extends GameObj{
    public BodyObj(Image img, int x, int y,GameWin frame) {
        super(img,x,y,frame);
    }

    @Override
    public void paintSelf(Graphics g) {
        super.paintSelf(g);
    }
}

6）FoodObj（食物类）

package com.obj;

import com.GameWin;
import com.utils.GameUtils;

import java.awt.*;
import java.util.Random;

public class FoodObj extends GameObj{
    //随机数对象
    Random random=new Random();

    public FoodObj() {
        super();
    }
    public FoodObj(Image img, int x, int y, GameWin frame) {
        super(img, x, y, frame);
    }

    public FoodObj getFood(){
        return new FoodObj(GameUtils.foodImg,random.nextInt(20)*30,(1+random.nextInt(19))*30,this.frame);
    }

    @Override
    public void paintSelf(Graphics g) {
        super.paintSelf(g);
    }
}