I am wondering if there is an easy way to extend the functionality of the Apex Listener.
My problem is that I cannot easily upload multiple files at once by using Internet Explorer 8 and Apex. Internet Explorer does not allow for multiple file selection in the file dialogue. There are HTML5 plugins available but IE 8 does not support HTML5 so I cannot use them. There are also Flash solutions to the problem but I'm having trouble getting Apex to understand the POST data that come from these solutions. Since the Flash solution is a pre-canned one, there is not much in the way of configuring the way it POSTS data to the server.
So I'm looking for a more custom solution. What I was thinking is just writing my own Java upload handler and sticking it on the same server as the Apex listener.