@Override public void stop(){
  for (  Thread thread : threads) {
    thread.interrupt();
  }
  try {
    for (    Thread thread : threads) {
      thread.join();
    }
  }
 catch (  InterruptedException e) {
  }
}

@ Override public void stop ( ) { for ( Thread thread : threads ) { thread . interrupt ( ) ; } try { for ( Thread thread : threads ) { thread . join ( ) ; } } catch ( InterruptedException e ) { } }
kill all the threads , and shutdown .
