You will find it much easier to use the Pentaho platform. Pentaho already has everything you need to deploy your Jasper report, all you have to do is drop in the report, describe how you want your report to appear by way of a solution file, and thats all there is to it.
Check it out at http://www.pentaho.org
or download the demo (which has examples of deployed Jasper reports):
good luck with your project,
Pentaho Geek Wrangler
I'm sorry, I should have mentioned that the Pentaho demo is a fully preconfigured JBoss server with the Pentaho platform setup with portal capabilities. You can see examples of Jasper reports displayed inside the JBoss portal, or launched from a jsp or servlet URL.
good luck again!
Pentaho Community Chick