2个有关线程的问题，

Question

1.run()后面加上sleep(1);
2.代码贴全了看看

Answer 1

最好不要调用destroy(),线程在完成了工作后会被系统回收,当你的线程有无限循环注意在什么时候跳出,还要为避免利己线程!

Answer 2

1. 代码2 肯定是定义的时候写了boolean inApplet = true;

Answer 3

不好意思，看花眼了，inApplet前面有定义.
还有一个问题，有关超级线程的，是不是优先级最高的线程自动被设为超级线程。

Answer 4

还有个问题，书上是用Thread.MIN_PRIORITY这个变量来设线程优先权级，我用Thread.MAX_PRIORITY来设的话，程序就不能运行，为什么？原代码：
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.Frame;
import Threader;
public class GreatRace extends java.applet.Applet implements Runnable{Threader theRacers[];                         
static int racerCount=3;                           //竞赛者人数
Thread theThreads[];
Thread thisThread;
static boolean inApplet=true;
int numberofThreadsAtStart;
public void init(){
numberofThreadsAtStart=Thread.activeCount();
setLayout(new GridLayout(racerCount,1));
theRacers=new Threader[racerCount];
theThreads=new Thread[racerCount];
for(int x=0;x<racerCount;x++){
theRacers[x]=new Threader("Racer#"+x);
theRacers[x].setSize(getSize().width,getSize().height/racerCount);
add(theRacers[x]);
theThreads[x]=new Thread(theRacers[x]);  //new thread for each racers
theThreads[x].setPriority(Thread.MIN_PRIORITY+x);   //设线程优先权级。
}
}
public void start(){
for (int x=0;x<racerCount;x++)
theThreads[x].start();
thisThread=new Thread(this);
thisThread.start();
}public void stop(){
for(int x=0;x<racerCount;x++){
theRacers[x].stop();
}
}public void run(){
while(Thread.activeCount()>numberofThreadsAtStart+2){
try{
thisThread.sleep(100);
}
catch(InterruptedException e){
System.out.println("this Thread is interrupt");
}
}if(inApplet){
stop();                              
destroy();                          
}
else
System.exit(0);
}public static void main(String argv[]){
inApplet=false;
if(argv.length>0)
racerCount=Integer.parseInt(argv[0]);
Frame theFrame=new Frame("the great thread race");
GreatRace theRace=new GreatRace();
theFrame.setSize(400,200);
theFrame.add("Center",theRace);
theFrame.show();
theRace.init();
theFrame.pack();
theRace.start();
}
}/*Threader类*/
import java.awt.Graphics;
import java.awt.Color;
public class Threader extends java.awt.Canvas implements Runnable{
int myposition=0;
String myname;
int numberofsteps=1600;
boolean keepRunning=true;
public Threader(String inname){
myname=new String(inname);
}public synchronized void paint(Graphics g){
g.setColor(Color.black);
g.drawLine(0,getSize().height/2,getSize().width,getSize().height/2);
g.setColor(Color.yellow);
g.fillOval((myposition*getSize().width/numberofsteps),0,15,getSize().height);
}public void stop(){
keepRunning=false;                        
}public void run(){
while((myposition<numberofsteps)&& keepRunning){
myposition++;
repaint();
try{
Thread.currentThread().sleep(10);
}
catch(Exception e){
System.out.println("sleep");
}
System.out.println("Thrader"+myname+"finished the race");
}
}
}