why need to catch InterruptedException in the Sleep?
<blockquote>
  <p><strong>Possible Duplicate:</strong><br>
  <a href="http://stackoverflow.com/questions/1087475/when-does-javas-thread-sleep-throw-interruptedexception">When does Java&#39;s Thread.sleep throw InterruptedException?</a>  </p>
</blockquote>



<p>I saw we have to catch  InterruptedException  in the Thread.Sleep method, why? I never saw this exception occured in the real time. Any clue?</p>
