JAVA贪吃蛇课程怎么处理食物的随机性

JAVA贪吃蛇课程怎么处理食物的随机性

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.image.BufferedImage;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JFrame;
public class InterFace extends JFrame {

public static final int WIDTH = 800, HEIGHT = 600, SLEEPTIME = 200, L = 1,R = 2, U = 3, D = 4;
BufferedImage offersetImage= new BufferedImage(WIDTH, HEIGHT,BufferedImage.TYPE_3BYTE_BGR);;
Rectangle rect = new Rectangle(20, 40, 15 * 50, 15 * 35);
Snake snake;
Node node;
public InterFace() {
//创建"蛇"对象
snake = new Snake(this);
//创建"食物"对象
createNode();
this.setBounds(100, 100, WIDTH, HEIGHT);
//添加键盘监听器
this.addKeyListener(new KeyAdapter() {
public void keyPressed(KeyEvent arg0) {
System.out.println(arg0.getKeyCode());
switch (arg0.getKeyCode()) {
//映射上下左右4个键位
case KeyEvent.VK_LEFT:
snake.dir = L;
break;
case KeyEvent.VK_RIGHT:
snake.dir = R;
break;
case KeyEvent.VK_UP:
snake.dir = U;
break;
case KeyEvent.VK_DOWN:
snake.dir = D;
}
}
});
this.setTitle("贪吃蛇 0.1 By ： Easy");
this.setDefaultCloseOperation(EXIT_ON_CLOSE);
this.setVisible(true);
//启动线程,开始执行
new Thread(new ThreadUpadte()).start();
}
public void paint(Graphics g) {
Graphics2D g2d = (Graphics2D) offersetImage.getGraphics();
g2d.setColor(Color.white);
g2d.fillRect(0, 0, WIDTH, HEIGHT);
g2d.setColor(Color.black);
g2d.drawRect(rect.x, rect.y, rect.width, rect.height);
//如果蛇碰撞(吃)到食物，则创建新食物
if (snake.hit(node)) {
createNode();
}
snake.draw(g2d);
node.draw(g2d);
g.drawImage(offersetImage, 0, 0, null);
}
class ThreadUpadte implements Runnable {
public void run() {
//无限重绘画面
while (true) {
try {
Thread.sleep(SLEEPTIME);
repaint(); //
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}

public void createNode() {
//随机食物的出现位置
int x = (int) (Math.random() * 650) + 50,y = (int) (Math.random() * 500) + 50;
Color color = Color.blue;
node = new Node(x, y, color);
}
public static void main(String args[]) {
new InterFace();
}
}

class Node {
int x, y, width = 15, height = 15;
Color color;
public Node(int x, int y, Color color) {
this(x, y);
this.color = color;
}
public Node(int x, int y) {
this.x = x;
this.y = y;
this.color = color.black;
}
public void draw(Graphics2D g2d) {
g2d.setColor(color);
g2d.drawRect(x, y, width, height);
}
public Rectangle getRect() {
return new Rectangle(x, y, width, height);
}
}

class Snake {
public List nodes = new ArrayList();
InterFace interFace;
int dir=InterFace.R;
public Snake(InterFace interFace) {
this.interFace = interFace;
nodes.add(new Node(20 + 150, 40 + 150));
addNode();
}

public boolean hit(Node node) {
//遍历整个蛇体是否与食物碰撞
for (int i = 0; i < nodes.size(); i++) {
if (nodes.get(i).getRect().intersects(node.getRect())) {
addNode();
return true;
}
}
return false;
}
public void draw(Graphics2D g2d) {
for (int i = 0; i < nodes.size(); i++) {
nodes.get(i).draw(g2d);
}
move();
}
public void move() {
nodes.remove((nodes.size() - 1));
addNode();
}
public synchronized void addNode() {
Node nodeTempNode = nodes.get(0);
//如果方向
switch (dir) {
case InterFace.L:
//判断是否会撞墙
if (nodeTempNode.x <= 20) {
nodeTempNode = new Node(20 + 15 * 50, nodeTempNode.y);
}
nodes.add(0, new Node(nodeTempNode.x - nodeTempNode.width,
nodeTempNode.y));
break;
case InterFace.R:
//判断是否会撞墙
if (nodeTempNode.x >= 20 + 15 * 50 - nodeTempNode.width) {
nodeTempNode = new Node(20 - nodeTempNode.width, nodeTempNode.y);
}
nodes.add(0, new Node(nodeTempNode.x + nodeTempNode.width,
nodeTempNode.y));
break;
case InterFace.U:
//判断是否会撞墙
if (nodeTempNode.y <= 40) {
nodeTempNode = new Node(nodeTempNode.x, 40 + 15 * 35);
}
nodes.add(0, new Node(nodeTempNode.x, nodeTempNode.y - nodeTempNode.height));
break;
case InterFace.D:
//判断是否会撞墙
if (nodeTempNode.y >= 40 + 15 * 35 - nodeTempNode.height) {
nodeTempNode = new Node(nodeTempNode.x,40 - nodeTempNode.height);
}
nodes.add(0, new Node(nodeTempNode.x, nodeTempNode.y + nodeTempNode.height));
break;
}
}
}

使用随机数，详情自己百度 java随机数去吧