public class LinesRectsOvalsJPanel extends JPanel implements Runnable
{
private final int sleeptime=5;
private int x=400;
private int y=0;
private double xspeed=1.0,yspeed=1.0;
public LinesRectsOvalsJPanel(int x,int y,double xspeed,double yspeed){
this.x=x;
this.y=y;
this.xspeed=xspeed;
this.yspeed=yspeed;
}
public int getx(){
return x;
}
public int gety(){
return y;
}
public void setballxy(int x,int y){
this.x=x;
this.y=y;
}
public void paint( Graphics g)
{
super.paint(g);
this.setBackground( Color.WHITE );
g.setColor( Color.MAGENTA );
g.fillOval( this.getx(),this.gety(),20, 20);
} // end method paintComponent
public void run()
{
while(true)
{
if(x + xspeed + 2*20 > 800 || x + xspeed < 0){ //当在X轴上碰到墙时,X轴行进方向改变
xspeed*=-1;
}else{
x += xspeed; //没碰壁时继续前进
}
if(y + yspeed + 2*20 > 800 || y + yspeed < 0){ //当在Y轴上碰到墙时,Y轴行进方向改变
yspeed*=-1;
}else{
y += yspeed;
}
this.repaint();
try{
Thread.sleep(sleeptime);
}catch(InterruptedException e){
e.printStackTrace();
}
}
}
} // end class LinesRectsOvalsJPanel
public class LinesRectsOvals
{
// execute application
public static void main( String[] args )
{
// create frame for LinesRectsOvalsJPanel
JFrame frame =
new JFrame( "Drawing lines, rectangles and ovals" );
frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
LinesRectsOvalsJPanel linesRectsOvalsJPanel =
new LinesRectsOvalsJPanel(400,0,1.0,1.0);
LinesRectsOvalsJPanel linesRectsOvalsJPane2 =
new LinesRectsOvalsJPanel(700,0,1.0,1.0);
linesRectsOvalsJPanel.setBackground( Color.WHITE );
linesRectsOvalsJPane2.setBackground( Color.WHITE );
ExecutorService threadExecutor=Executors.newCachedThreadPool();
frame.add( linesRectsOvalsJPanel ); // add panel to frame
frame.add( linesRectsOvalsJPane2 );
frame.setSize( 800, 800 ); // set frame size
frame.setVisible( true ); // display frame
threadExecutor.execute(linesRectsOvalsJPane2);
threadExecutor.execute(linesRectsOvalsJPanel);
// linesRectsOvalsJPane2.ballmove();
} // end main
} // end class LinesRectsOvals
程序中明明初始化了两个弹球，为什么最后运行的时候还是一个。。。新手，不懂。。。
