title: Audio file duration without AudioSystem class in Java (GAE)?
body: <p>There is already a more general answer (Java) at <a href="https://stackoverflow.com/questions/3009908/how-do-i-get-a-sound-files-total-time-in-java">https://stackoverflow.com/questions/3009908/how-do-i-get-a-sound-files-total-time-in-java</a> but unfortunately</p>
  
  <pre><code>java.lang.NoClassDefFoundError: javax.sound.sampled.AudioSystem is a restricted class. Please see the Google App Engine developer's guide for more details.
  </code></pre>
  
  <p><code>AudioSystem</code> is not on the <a href="https://developers.google.com/appengine/docs/java/jrewhitelist?hl=hr&amp;csw=1" rel="nofollow">Google App Engine JRE Class White List</a> and therefore can't be used. Any other approach?</p>
  
  <p>I have (already uploaded) audio files sitting on Google Cloud Storage (GCS) and I can load them into <code>ByteArrayInputStream</code> but somehow I need to convert them into <code>AudioInputStream</code> to get the audio file duration (and save the duration in the database).</p>