面试题：子线程循环10次，接着主线程循环100次，接着又回到子线程循环10次，接着再回到主线程循环100次，如此循环50次，请写出程序

public class ThreadTest {
 public static void main(String[] args) throws InterruptedException {
  // TODO Auto-generated method stub
        new ThreadTest().init();
 }
 public void init() throws InterruptedException
 {
   final Business business=new Business();
   new Thread(new Runnable()
   {
    public void run(){
     for(int i=0;i<50;i++)
     {
      business.SubThread(i);
     }
    }
   }
   ).start();
   Thread.sleep(1000);  //此行为了让主线程让出CPU，让子线程先执行
   for(int i=0;i<50;i++)
   {
    business.MainThread(i);
   }
  }
  class Business
  {
   //boolean bShouldSub=true;
   public synchronized void MainThread(int i) throws InterruptedException
   {   
    for(int j=0;j<100;j++)
    {
     System.out.println(Thread.currentThread().getName()+":yu_i="+i+",j="+j);
    }
    this.notify();
    try{
     this.wait();
    }catch(InterruptedException e){
     e.printStackTrace();
    }
    
   }
   public synchronized void SubThread(int i)
   {
    for(int j=0;j<10;j++)
    {
     System.out.println(Thread.currentThread().getName()+":bing_i="+i+",j="+j);
    }
    this.notify();
    try{
     this.wait();
    }catch(InterruptedException e){
     e.printStackTrace();
    }
    
    }
   }
  }