title: Delete files, directories and buckets in amazon s3 java
body: <p>I'm wondering how to do this. I looked at the sdk documentation and have some examples, but am confused how the syntax generally goes. </p>
  
  <p>If I want to delete a file, I assume I use <code>deleteObject(path, key)</code>. However, what is the "key"? </p>
  
  <p>Also how do you delete a directory? I can't seem to find a method for doing that.</p>