[JAVA] Thread: non capisco output di esempio

[matthew80]

Salve,

Non capisco la successione dell'output del seguente esempio (che ho semplificato per brevità):

public class ThreadTester {
   public static void main( String args[] )
   {
      PrintThread thread1, thread2;

      thread1 = new PrintThread( "thread1" );
      thread2 = new PrintThread( "thread2" );
     
      System.err.println( "\nStarting threads" );

      thread1.start();
      thread2.start();
     
      System.err.println( "Threads started\n" );
   }
}

class PrintThread extends Thread {
   private int sleepTime;

   public PrintThread( String name )
   {
      super( name );

      sleepTime = 2;

      System.err.println( "Name: " + getName() +
                          ";  sleep: " + sleepTime );
   }

   public void run()
   {
      try {
         System.err.println( getName() + " going to sleep" );
         Thread.sleep( sleepTime );
      }
      catch ( InterruptedException exception ) {
         System.err.println( exception.toString() );
      }

      System.err.println( getName() + " done sleeping" );
   }
} 

Ecco l'output:

Name: thread1; sleep: 2
Name: thread2; sleep: 2

Starting threads
Threads started

thread1 going to sleep
thread2 going to sleep
thread1 done sleeping
thread2 done sleeping

Perchè la stringa Threads started non sta alla fine?

Grazie dell'attenzione.
Matteo