title: AWS S3 Java API MultipleFileDownload add worker
body: <p>I'm writing a swing GUI for a program using AWS S3 java SDK; I am using a MultipleFileDownload naed download and when it starts downloading I have to add:</p>
  
  <pre><code> download.waitForCompletion();
  </code></pre>
  
  <p>this is a blocking call so even if I addeded a listener to update a progress bar status (JProgressBar)</p>
  
  <pre><code> download.addProgressListener(createProgressListener(download));
  </code></pre>
  
  <p>the progressbar won't change status until the download process has succesfully ended.</p>
  
  <p>Is there any way to add a 2nd worker or thread to update the progress bar while downloading ?</p>