模拟弹子台球--java多线程应用

package MarblesThread;

import java.awt.Color;
import java.awt.Graphics;

public class Marbles implements Runnable{
public Marbles(){

}

public Marbles(int startx, int starty, int xdir, int ydir, Table table){
this.table = table;
this.startX = startx;
this.startY = starty;
this.xDir = xdir;
this.yDir = ydir;
}

@Override
public void run(){
while(true){
if((startX > table.getSize().width - 25) || (startX < 0)){
xDir *= -1;
}
if((startY > table.getSize().width - 25) || (startY < 0)){
yDir *= -1;
}
startX += xDir;
startY += yDir;
try{
Thread.sleep(1000);
}catch(Exception e){
e.printStackTrace();
}
table.repaint();
}

}

public void draw(Graphics g){
g.setColor(Color.black);
g.fillOval(startX, startY, 30, 30);
g.setColor(Color.white);
g.fillOval(startX + 5, startY + 5, 8, 6);
}

Table table = null;
int startX, startY;
int xDir, yDir;
}

package MarblesThread;

import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

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

public class Table extends JFrame implements ActionListener{
public Table(){
panel.add(startButton);
startButton.addActionListener(this);
setContentPane(panel);

setSize(400, 500);
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

addWindowListener(new WindowAdapter(){
@Override
public void windowClosing(WindowEvent e){
System.exit(0);
}
});
}

public static void main(String[] args){
new Table();
}

private final JButton startButton = new JButton("开始");
JPanel panel = new JPanel();
Marbles[] marbles = new Marbles[10];
private final int speedMin = 2;

@Override
public void actionPerformed(ActionEvent e){
for(int i = 0; i < marbles.length; i++){
int xDir = (int) (Math.random() * 10 + speedMin);
int yDir = (int) (Math.random() * 10 + speedMin);
int startX = (int) (Math.random() * getSize().width);
int startY = (int) (Math.random() * getSize().height);
marbles[i] = new Marbles(startX, startY, xDir, yDir, this);
new Thread(marbles[i]).start();
}
}

@Override
public void paint(Graphics g){
super.paint(g);
for(int i = 0; i < marbles.length; i++){
if(marbles[i] != null){
marbles[i].draw(g);
}
}
}
}