一个java中的多线程的问题！
package   cn.junco.mutilthread;

public   class   ThreadTest   {

/**
  *   @param   args
  */



public   static   void   main(String[]   args)   {
//   TODO   Auto-generated   method   stub
PrintThread   thread1,thread2,thread3,thread4;
thread1=new   PrintThread( "thread1 ");

thread2=new   PrintThread( "thread2 ");
thread3=new   PrintThread( "thread3 ");
thread4=new   PrintThread( "thread4 ");
System.err.println( "\n   Starting   threads ");
thread1.start();
thread2.start();
thread3.start();
thread4.start();
System.err.println( "Threads   started\n ");
}

}

class   PrintThread   extends   Thread
{
      private   int   sleepTime   ;
      public   PrintThread(String   name)
      {
      super(name);
      sleepTime=(int)(Math.random()*5000);
      System.err.println( "Name: "+getName()+ "     sleep: "+sleepTime);
     
      }
      public   void   run()
      {
      try   {
System.err.println(getName()+ "   going   to   sleep   ");
Thread.sleep(sleepTime);
}   catch   (Exception   e)   {
//   TODO:   handle   exception
}
System.err.println(getName()+ "   done   sleeping ");
      }
}

结果一：Name:thread4     sleep:4023

  Starting   threads
thread1   going   to   sleep  
Threads   started

thread3   going   to   sleep  
thread2   going   to   sleep  
thread4   going   to   sleep  
thread2   done   sleeping
thread1   done   sleeping
thread3   done   sleeping
thread4   done   sleeping
结果二：Name:thread1     sleep:4878
Name:thread2     sleep:2999
Name:thread3     sleep:1695
Name:thread4     sleep:7

  Starting   threads
thread1   going   to   sleep  
Threads   started

thread3   going   to   sleep  
thread2   going   to   sleep  
thread4   going   to   sleep  
thread4   done   sleeping
thread3   done   sleeping
thread2   done   sleeping
thread1   done   sleeping
问题是为什么Threads   started这个输出结果直接的就在thread1   going   to   sleep   之后
问题2     ，4个thread   的执行顺序的优先级有什么原则吗？

------解决方案--------------------
System.err.println在main线程，输出顺序也不是固定的
没有设定优先级，原则上来讲，没有固定的执行顺序