title: @Async with outstream and thread.sleep method
body: <p>A simple question on @Async annotation.</p>
  
  <p>For example: A method is @Async annotated and it contains thread.sleep for few seconds.
  And after the sleep, their is a outStream.println. Then what is the result.</p>
  
  <p>I have used ThreadPoolTaskExecutor as executor</p>
  
  <p>I just want to know as i have tried above with a sleep of 5 seconds, but getting outStream.println in fraction of second. So I just want to understand if this is how Async annotation works i.e., if it has given the instant response and thread.sleep is executed by other thread.</p>