我试图创建一个Java小程序，它在applet窗口中弹出几个球，每个小程序都有自己的线程和自己的按钮。如何用球添加到每个按钮线程？
这是我的BiliardBalls.java类的代码
import java.awt.*;
import java.applet.*;
class CollideBall
{
int width, height;
public static final int diameter=30;
double x, y, xinc, yinc, coll_x, coll_y;
boolean collide;
Color color;
Graphics g;
public CollideBall(int w, int h, int x, int y, double xinc, double yinc, Color c)
{
width=w;
height=h;
this.x=x;
this.y=y;
this.xinc=xinc;
this.yinc=yinc;
color=c;
}
public double getCenterX() {return x+diameter/2;}
public double getCenterY() {return y+diameter/2;}
public void move()
{
if (collide)
{
double xvect=coll_x-getCenterX();
double yvect=coll_y-getCenterY();
if((xinc>0 && xvect>0) || (xinc<0 && xvect<0))
xinc=-xinc;
if((yinc>0 && yvect>0) || (yinc<0 && yvect<0))
yinc=-yinc;
collide=false;
}
x+=xinc;
y+=yinc;
//border
if(x<0 || x>width-diameter)
{xinc=-xinc; x+=xinc; }
if(y<0 || y>height-diameter)
{yinc=-yinc; y+=yinc;}
}
public void hit(CollideBall b){
if(!collide)
{coll_x=b.getCenterX(); coll_y=b.getCenterY(); collide=true;}}
public void paint(Graphics gr){
g=gr; g.setColor(color);
g.fillOval((int)x,(int)y,diameter,diameter); }
}
@SuppressWarnings("serial")
public class BiliardBalls extends Applet implements Runnable
{
Thread runner1;
Thread runner2;
Thread runner3;
Thread runner4;
Image Buffer;
Graphics gBuffer;
CollideBall ball[];
AudioClip Collision;
boolean collision;
static final int MAX=4;
Button a = new Button("A");
Button b = new Button("B");
Button c = new Button("C");
Button d = new Button("D");
boolean stop_a = true;
boolean stop_b = true;
boolean stop_c = true;
boolean stop_d = true;
boolean isClicked = false;
@SuppressWarnings("deprecation")
public void init()
{
setSize(500,500);
Buffer=createImage(size().width,size().height);
gBuffer=Buffer.getGraphics();
ball=new CollideBall[MAX];
final int w=size().width;
final int h=size().height;
try{Collision=getAudioClip(getCodeBase());}
catch (Exception e){}
ball[0]=new CollideBall(w,h,50,20,1.5,2.0,Color.orange);
ball[1]=new CollideBall(w,h,60,100,2.0,-3.0,Color.red);
ball[2]=new CollideBall(w,h,15,70,-2.0,-2.5,Color.pink);
ball[3]=new CollideBall(w,h,150,60,-2.7,-2.0,Color.cyan);
a = new Button("Run first ball");
add(a);
b = new Button("Run second ball");
add(b);
c = new Button("Run third ball");
add(c);
d = new Button("Run fourth ball");
add(d);
}
public boolean action(Event evt, Object arg ) {
if (evt.target==a)
{
if(runner1 != null)
{ runner1.stop();
runner1 = null;
a.setLabel("run first ball");
}
else if (runner1 == null)
{ runner1 = new Thread(this);
runner1.start();
a.setLabel("stop first ball");
}
stop_a = !stop_a;
return true;}
if (evt.target==b)
{
if(runner2 != null)
{ runner2.stop();
runner2 = null;
b.setLabel("run second ball");
}
else if (runner2 == null)
{ runner2 = new Thread( this);
runner2.start();
b.setLabel("stop second ball");
}
stop_b = !stop_b;
return true;}
if (evt.target==c)
{
if(runner3 != null)
{ runner3.stop();
runner3 = null;
c.setLabel("run third ball");
}
else if (runner3 == null)
{ runner3 = new Thread( this);
runner3.start();
c.setLabel("stop third ball");
}
stop_c = !stop_c;
return true;}
if (evt.target==d)
{
if(runner4 != null)
{ runner4.stop();
runner4 = null;
d.setLabel("run fourth ball");
}
else if (runner4 == null)
{ runner4 = new Thread( this);
runner4.start();
d.setLabel("stop fourth ball");
}
stop_d = !stop_d;
return true;}
else
return super.action(evt,arg);
}
@SuppressWarnings("static-access")
public void run()
{
while(true)
{
try {runner1.sleep(13);
}
catch (Exception e) { }
for(int i=0;i<MAX;i++){
ball[i].move();}
handleCollision();
repaint();
}
}
@SuppressWarnings("static-access")
boolean collide(CollideBall b1, CollideBall b2)
{
double wx=b1.getCenterX()-b2.getCenterX();
double wy=b1.getCenterY()-b2.getCenterY();
double distance=Math.sqrt(wx*wx+wy*wy);
if(distance<b1.diameter)
{
if(collision)Collision.play();
return true;}
return false;
}
private void handleCollision()
{ for(int i=0;i<MAX;i++)
for(int j=0;j<MAX;j++) {
if(i!=j) {
if(collide(ball[i], ball[j])){
ball[i].hit(ball[j]);
ball[j].hit(ball[i]);}}}
}
public void update(Graphics g) { paint(g);}
@SuppressWarnings("deprecation")
public void paint(Graphics g)
{
gBuffer.setColor(Color.black);
gBuffer.fillRect(0,0,size().width,size().height);
gBuffer.setColor(Color.green);
for(int x=0;x<size().width;x+=50)
gBuffer.drawLine(x,0,x,size().height);
for(int y=0;y<size().height;y+=50)
gBuffer.drawLine(0,y,size().width,y);
for(int i=0;i<MAX;i++)
ball[i].paint(gBuffer);
g.drawImage (Buffer,0,0, this);
}
}