how can i create a custom stack which includes my Java web app, so that it can directly be launched into Amazon Elastic Beanstalk or into a standalone AWS Virtual machine

I am working to develop a web app in Java Server Faces.

Now I want to create an AMI image which installs JBOSS and this web app. I want to be able to use this AMI for both standalone EC2 instances, as well as in Elastic Beanstalk.

How do I create such a machine image? Any help/guides/howtos would be appreciated.