suggestion request!

[Andrea Chiumenti]

Hello,

 I wanto to create a web project that has a service named AsynchronousRemotePrinting.
This service grants to you to directly send reports to your local printer simply clicking on a web-link on your browser, this will be a feature of an
OS project that will make heavy use of hivemind(and hivetranse) and tapestry.

The way i can make possible to print on the user local printer from a web browser is relatively simple:
1) When the user log into the application for the first time he starts a client application via webstart, and identifies himself.
2) Asking for a report to print ( click on a link on the browser), means to save the report by email or webdav.
3) The  webstart application has a chron job that periodically asks to the server if the user has some report to print
4) If yes, then, throught Hessian, the local application downloads the report and prints it to the preferred printer.

Now my implementation problem is this:

1) If I implement the service as an hessian service, I can define clean service methods (no user credentials are requested as parameters) but the service will
remain tied to caucho (the service class can be only a caucho servlet, since in methods I have to distinguish between users to transmit the right reports).

2) If I don't want my service to be strongly tied to caucho the I have to adopt the hiveremoting.caucho solution, but then I have to transimt somehow the principal
as method parameter. I also think that principal has to be validated at each service call since it doesn't come from server side,.

So I don't know what should be a better solution: caucho tiding or Principal passed as parameter ?
Currently I've not been able to think to other possible solutions and I'm actually more interested in the caucho heavy tie  solution.
I'd like to have some suggestion or opinion if possible.
Thanks in advance,
kiuma