How to upload an attachment to Google sites.

[project gcourse]

Hi.

I want to upload an attachment to my Google sites with a Java HttpServlet.

The object that I want to upload is an InputStream class object. 

Google sites API supports a method that receive in input an object of the class File, but in the app engine I can't use the OutputStream in order to generate a "File" form an InputStream.

What could I use? A Post request could resolve my problem, and if so...how I generate that request?

Thanks...

Regards.