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java實(shí)現(xiàn)小球碰撞功能

更新時(shí)間：2021年01月29日 09:14:22 作者：mayifan_blog

這篇文章主要為大家詳細(xì)介紹了java實(shí)現(xiàn)小球碰撞功能，文中示例代碼介紹的非常詳細(xì)，具有一定的參考價(jià)值，感興趣的小伙伴們可以參考一下

本文實(shí)例為大家分享了java實(shí)現(xiàn)小球碰撞的具體代碼，供大家參考，具體內(nèi)容如下

這次我們做一個(gè)小球的碰撞的游戲，規(guī)則是：按下添加按鈕，窗口的中心部分會(huì)產(chǎn)生一個(gè)小球（剛開(kāi)始默認(rèn)為黑色），四個(gè)方向隨機(jī)產(chǎn)生，發(fā)射小球，再次按下即產(chǎn)生兩個(gè)小球。當(dāng)小球碰到窗體邊緣的時(shí)候會(huì)產(chǎn)生反彈，當(dāng)兩個(gè)小球接觸時(shí)會(huì)產(chǎn)生碰撞，雙方交換速度，向相反方向移動(dòng)。我們可以選擇相應(yīng)的顏色來(lái)改變下一個(gè)發(fā)射的小球顏色。當(dāng)按下清除可以清除屏幕上的小球，當(dāng)按下添加則會(huì)繼續(xù)產(chǎn)生小球。最后我們還添加了自動(dòng)產(chǎn)生小球的功能，按下開(kāi)關(guān)，在屏幕中間會(huì)定時(shí)產(chǎn)生小球。接下來(lái)，我們來(lái)展示代碼部分。

public class Jframe {
 private Ball[] arrayball = new Ball[100];
 public static void main(String[] args) {
 Jframe frame = new Jframe();
 frame.showUI();
 }
 public void showUI() {
 javax.swing.JFrame jf = new javax.swing.JFrame();
 jf.setSize(1000, 1000);
 jf.getContentPane().setBackground(Color.WHITE);
 jf.setTitle("小球");
 jf.setDefaultCloseOperation(3);
 // 設(shè)置居中顯示
 jf.setLocationRelativeTo(null);
 JPanel jp1 =new JPanel(); 
 JButton jb1 = new JButton("添加");
 jp1.add(jb1);
 // jb1.setBounds(100,50, 40, 20);
 JButton jb2 = new JButton("暫停");
 jp1.add(jb2);
 // jb1.setBounds(200,50, 40, 20);
 JButton jb3 = new JButton("清除");
 jp1.add(jb3);
 // jb1.setBounds(300,50, 40, 20);
 JButton jb4 = new JButton("自動(dòng)添加");
 jp1.add(jb4); 
 jf.add(jp1,BorderLayout.NORTH); 
  Mouse mouse = new Mouse();  
 Color[] color = {Color.RED,Color.BLUE,Color.BLACK,Color.GREEN,Color.YELLOW};
 for(int i=0;i<color.length;i++){
 JButton jbu = new JButton();
 jbu.setBackground(color[i]);
 jbu.setPreferredSize(new Dimension(30, 30));
 jp1.add(jbu);
 jbu.addActionListener(mouse);
 } 
 jb1.addActionListener(mouse);
 jb2.addActionListener(mouse);
 jb3.addActionListener(mouse);
 jb4.addActionListener(mouse);
 jf.addMouseListener(mouse);
 jf.addMouseMotionListener(mouse);
 BallJpanel cp = new BallJpanel(); 
 cp.setBackground(Color.WHITE);
 jf.add(cp,BorderLayout.CENTER);
 jf.setVisible(true);   
 Graphics g = cp.getGraphics();
 mouse.setcp(cp); 
 mouse.setg(g);
 mouse.setarrayball(arrayball);
 mouse.setmouse(mouse);
 cp.setarrayball(arrayball); 
 }
}

這是窗體的基本配置，采用邊框布局，上方放置按鈕，中間是畫(huà)布。我們?yōu)榘粹o添加了動(dòng)作監(jiān)聽(tīng)器，并使用了一系列的方法來(lái)把對(duì)象傳遞到其他類(lèi)中。

public class Ball {
 public int size = 90; // 小球的直徑
 public int x = 500; // 小球所在的x坐標(biāo)
 public int y = 500; // 小球所在的y坐標(biāo)
 public int vx = 5;
 public int vy = 5;
 public BallJpanel cp;
 public Color color = Color.BLACK;
 public int max_x, max_y, Min_x, Min_y;
 private Ball[] arrayball;
 public void setcp(BallJpanel cp) {
 this.cp = cp;
 }
 public void setarrayball(Ball[] arrayball) {
 this.arrayball = arrayball;
 }
 public void setX(int x) {
 this.x = x;
 }
 public int getX() {
 return x;
 }
 public void setY(int y) {
 this.y = y;
 }
 public int setY() {
 return y;
 }
 public Ball(int x, int y, int vx, int vy, Color color) {
 this.x = x;
 this.y = y;
 this.vx = vx;
 this.vy = vy;
 this.color = color;
 }
 public void ballMove(Graphics g) {
 x += vx;
 y += vy;
 max_y = cp.getHeight();
 max_x = cp.getWidth();

 if (x <= size / 2) {
 x = size / 2;
 vx = -vx;
 }
 if (y <= size / 2) {
 y = size / 2;
 vy = -vy;
 }
 if (x + size / 2 >= max_x) {
 x = max_x - size / 2;
 vx = -vx;
 }
 if (y + size / 2 >= max_y) {
 y = max_y - size / 2;
 vy = -vy;
 }
 for (int i = 0; i < arrayball.length; i++) 
 {
 if (arrayball[i] == null)
 break;
 Ball ball = arrayball[i];
 if (this.equals(ball))
 continue;
 if ((ball.x - this.x) * (ball.x - this.x) + (ball.y - this.y) * (ball.y - this.y) <= size * size)
 {
 int tempvx = this.vx;
 int tempvy = this.vy;
 this.vx = ball.vx;
 this.vy = ball.vy;
 ball.vx = tempvx;
 ball.vy = tempvy;
 while ((ball.x - this.x) * (ball.x - this.x) + (ball.y - this.y) * (ball.y - this.y) <= size * size)
 {
  this.x += this.vx;
  this.y += this.vy;
  System.out.println("等待");
 }
 }
 }
 }
}

考慮到這是一個(gè)小球的運(yùn)動(dòng)系統(tǒng)，我們?yōu)樾∏驅(qū)懥艘粋€(gè)類(lèi)，添加小球的時(shí)候，會(huì)創(chuàng)建小球?qū)ο螅⑹蛊浍@得位置，顏色，速度等參數(shù)，并將其存入數(shù)組。小球的方法就是運(yùn)動(dòng)，每當(dāng)執(zhí)行ballMove方法，便會(huì)為小球修改位置坐標(biāo)（基于其速度），再判斷是否撞擊邊框，以及判斷是否和別的小球有坐標(biāo)重疊，如果有重疊，則跑一個(gè)循環(huán)，修改位置坐標(biāo)，使其分離。Ball這部分代碼和監(jiān)聽(tīng)器中的方法有所聯(lián)系，我們接下來(lái)介紹監(jiān)聽(tīng)器的方法。

public class Mouse implements MouseMotionListener, MouseListener, ActionListener {
 private Graphics g;
 private BallJpanel cp;
 private Ball[] arrayball;
 private int index = 0;
 private int x;
 private int y;
 private int vx;
 private int vy;
 private int random=1;
 private Color color=Color.black;
 private ThreadBall tb;
 private Mouse mouse;
 public int selfFlag=0;
 public void setmouse(Mouse mouse)
 {
  this.mouse= mouse;
 } 
 public void setarrayball(Ball[] arrayball) {
 this.arrayball = arrayball;
 }
 public void setg(Graphics g) {
 this.g = g;
 }
 public void setcp(BallJpanel cp) {
 this.cp = cp;
 }
 public void actionPerformed(ActionEvent e) { 
 if ("添加".equals(e.getActionCommand())) {
 System.out.println("添加");
 if (tb == null) {
 // 創(chuàng)建線程對(duì)象
 tb = new ThreadBall();
 tb.setcp(cp);
 tb.setarrayball(arrayball);
 tb.setg(g);
 tb.start();
 tb.setmouse(mouse);
 }
 tb.stopFlag=0;
 addBall(); 
 }
 if ("暫停".equals(e.getActionCommand())) { 
 if(tb!=null)
 {
  if(tb.stopFlag==0)
  {
   tb.stopFlag=1;
   System.out.println("暫停");
  }
  else 
  {
  tb.stopFlag=0;
  System.out.println("開(kāi)始");
  }
 } 
 }
 if ("清除".equals(e.getActionCommand())) {
 tb.stopFlag=1;
 cp.paint1(g);
 index=0;
 System.out.println("清除");
 }
 if ("自動(dòng)添加".equals(e.getActionCommand())){
 if(selfFlag==0)
 {selfFlag=1;System.out.println("自動(dòng)添加打開(kāi)");}
 else
 {selfFlag=0;System.out.println("自動(dòng)添加關(guān)閉");} 
 }  
 if("".equals(e.getActionCommand())){
 JButton jbu=(JButton)e.getSource();
 color=jbu.getBackground();
 g.setColor(color); 
 }
 }
 public void mouseDragged(MouseEvent e) {
 }
 public void mouseMoved(MouseEvent e) {
 }
 public void mouseClicked(MouseEvent e) {
 }
 public void mousePressed(MouseEvent e) {
 }
 public void mouseReleased(MouseEvent e) {
 }
 public void mouseEntered(MouseEvent e) {
 }
 public void mouseExited(MouseEvent e) {
 }
 public void addBall() {
 x = 500;
 y = 500;
 random=1+(int)(Math.random()*4);
 switch(random)
 {
 case 1:
 vx=5;
 vy=5;
 break;
 case 2:
 vx=-5;
 vy=-5; 
 break;
 case 3:
 vx=5;
 vy=-5; 
 break;
 case 4:
 vx=-5;
 vy=5; 
 break; 
 }
 Ball ball = new Ball(x, y,vx , vy, color); 
 arrayball[index++] = ball;
 }
}

監(jiān)聽(tīng)器中，我們?cè)O(shè)置了一系列參數(shù)來(lái)控制一些方法的開(kāi)啟和關(guān)閉，以及寫(xiě)了添加小球的方法，為其賦初值，隨機(jī)一個(gè)初始發(fā)射方向。這段代碼我們用到了線程。線程的使用分為兩步，創(chuàng)建線程對(duì)象并start線程。

public class ThreadBall extends Thread {
 private Graphics g;
 private BallJpanel cp;
 private Ball[] arrayball;
 public int stopFlag=0;
 private int add=0;
 private Mouse mouse;
 public void setmouse(Mouse mouse)
 {
 this.mouse=mouse;
 } 
 public void setcp(BallJpanel cp) {
 this.cp = cp; 
 }
 public void setg(Graphics g)
 {
 this.g=g;
 } 
 public void setarrayball(Ball[] arrayball) {
 this.arrayball = arrayball;
 }
 /**
 * 啟動(dòng)線程執(zhí)行的方法
 */
 public void run() {
 while (true) {
   if(stopFlag==0)
   {
  for (int i = 0; i < arrayball.length; i++) 
  {
  if(arrayball[i]==null)
  break; 
   Ball ball = arrayball[i];    
    ball.setarrayball(arrayball);   
  ball.setcp(cp);
  ball.ballMove(g);   
  } 
  cp.paint(g);
  add++;
  if(add==5000)
  add=0;
  if(add%50==0&&mouse.selfFlag==1)
  mouse.addBall();
   }
  try {
  Thread.sleep(50);
  } catch (InterruptedException e) {
  e.printStackTrace();
  }   
 }
 }
}

以上是線程的屬性和方法，此類(lèi)繼承Thread并重寫(xiě)了run方法。run方法的思路是循環(huán)調(diào)用ballMove方法修改小球坐標(biāo)，并調(diào)用paint方法更新顯示，我們加入了一個(gè)延時(shí)函數(shù)，來(lái)控制調(diào)用的頻率。

public class BallJpanel extends JPanel { 
 private Ball[] arrayball; 
 public void setarrayball(Ball[] arrayball)
 {
 this.arrayball=arrayball;
 } 
 public void paint(Graphics g)
 {
 super.paint(g); 
 for(int i=0;i<arrayball.length;i++)
 {
 if(arrayball[i]==null)
 {
 break; 
 }
 Ball ball=arrayball[i];
 g.setColor(ball.color);
 g.fillOval(ball.x-ball.size/2, ball.y-ball.size/2, ball.size, ball.size);
 }
 } 
 public void paint1(Graphics g)
 {
 super.paint(g); 
 for(int i=0;i<arrayball.length;i++)
 {
 if(arrayball[i]==null)
 {
 break; 
 }
 arrayball[i]=null; 
 }
 } 
}

BallJpanel類(lèi)寫(xiě)的是畫(huà)布，及小球的運(yùn)動(dòng)區(qū)域，畫(huà)筆也是從其對(duì)象cp上獲得。類(lèi)里用paint寫(xiě)畫(huà)面的重繪方法（包括畫(huà)板小球的重繪），paint1用來(lái)清空畫(huà)布及數(shù)組。

以上便是java小球運(yùn)動(dòng)的全部代碼，我們來(lái)看一下效果。