java会弹的小球（源码）

package com.jp.lianxi3; import java.awt.BorderLayout; import java.awt.Color; import java.awt.Graphics; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.util.ArrayList; import java.util.Iterator; import java.util.Timer; import java.util.TimerTask; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.border.LineBorder; class MyPanel extends JPanel{ private static final long serialVersionUID = -3860172538196407141L; private ArrayList<Qiu> l=new ArrayList<Qiu>(); private Iterator<Qiu> iter; public void paintComponent(Graphics g){ super.paintComponent(g); iter=l.iterator(); while(iter.hasNext()){ Qiu q=iter.next(); g.setColor(q.getC()); g.fillOval(q.getX(), q.getY(), q.getSize(), q.getSize()); } } public void addQiu(int x,int y,int size){ Qiu q=new Qiu(x,y,size); Thread t=new Thread(q); q.setC(new Color((int)(255*Math.random()),(int)(255*Math.random()),(int)(255*Math.random()))); t.start(); l.add(q); } public void clear(){ iter=l.iterator(); while(iter.hasNext()){ iter.next().setFlag(false); } l.clear(); repaint(); } class Qiu implements Runnable{//小球类 private int localX=500; private int localY=430; private int veX=1; private int veY=1; private int x=0; private int y=200; private int size=15; private Color c; private Timer timer=new Timer(); private boolean flag=true; public Qiu(int x, int y, int size) { super(); this.x = x; this.y = y; this.size = size; } public void setFlag(boolean flag){ this.flag=flag; } public Color getC() { return c; } public void setC(Color c) { this.c = c; } public int getX() { return x; } public int getY(){ return y; } public int getSize() { return size; } @Override public void run() { go(); } public void go(){ timer.schedule(new MyTimerTask(), 1000,1); } class MyTimerTask extends TimerTask{ @Override public void run() { if(flag==false){ timer.cancel(); }else{ if(x==(localX-size)){ veX=2; } if(x==0){ veX=1; } if(y==(localY-size)){ veY=1; } if(y==0){ veY=2; } if(veX==1){ x++;//向右 } if(veX==2){ x--;//向左 } if(veY==1){ y--;//向上 } if(veY==2){ y++;//向下 } repaint(); } } } } } public class DrawQiu2 extends JFrame implements ActionListener{ private static final long serialVersionUID = 8900839755152741240L; private MyPanel p=new MyPanel(); private JPanel pa=new JPanel(); private JButton bAdd=new JButton("添加"); private JButton bClear=new JButton("清空"); public DrawQiu2(){ bAdd.addActionListener(this); bClear.addActionListener(this); pa.add(bAdd); pa.add(bClear); pa.setBorder(LineBorder.createBlackLineBorder()); this.add(pa,BorderLayout.SOUTH); this.add(p); this.setSize(500, 500); this.setLocationRelativeTo(null); this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); this.setVisible(true); } @Override public void actionPerformed(ActionEvent e) { if(e.getSource()==bAdd) p.addQiu((int)((500-30)*Math.random()), (int)((500-30)*Math.random()),50); if(e.getSource()==bClear) p.clear(); } public static void main(String[] args) { new DrawQiu2(); } }