Custom ContentAdapter: How to distinguish between Files and Directories?

Hi,

I am trying to create a file-sharing system where publishers are required to
login to add content and consumers are given a URL to retrieve specific
content. The URL must not contain the path to the file, but instead use some
sort of UUID. A servlet would cross reference the UUID to the specific file.
I didn't find something which does this, so I have been working to create
the functionality with Slide.

I have begun with a custom Content Adapter which Slide triggers on create
events. My intention is to create a .URL file in the store to accompany
every file that is created. The .URL file would give the publisher the UUID
associated with their file.

Unfortunately, I can't figure out how to distinguish between a create event
on a file and a create event on a directory. What method should I be calling
to identify one versus the other?

Thanks,

Kris