if (isStopped) {
                try {
                    synchronized (thread) {
                        thread.wait();
                    }
                }
                catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }

------解决方案--------------------
在一个线程里是不能直接控制另外一个线程的运行状态，你只能通过设置状态标志的方式来间接控制。

class TimeCounter extends Thread
{

   Game game;

   TimeCounter(Game g)
   {
       game = g;
   }

   public void run()
   {
       try
       {
           Thread.sleep(1500);
       }
       catch(InterruptedException ex)
       {
           ex.printStackTrace();
       }
       if(game != null)
       {
           game.setStop(true);
       }
   }
}

class Game implements Runnable
{
//   只写重要的代码

   int head;
   boolean stop;
   Thread thread;

   public void run()
   {
       while(true)
       {
           synchronized(this)
           {
               head++;
               System.out.println(head);

               try
               {
                   if(stop)
                   {
                       this.wait(3000);
                       stop = false;
                   }
                   Thread.sleep(300);
               }
               catch(InterruptedException ex)
               {
                   ex.printStackTrace();
               }
           }
       }
   }

   public void start()
   {
       thread = new Thread(this);
       thread.start();
   }

   public void setStop(boolean stop)
   {
       this.stop = stop;
   }

   public static void main(String[] args)
   {
       Game game = new Game();