I am in the process of creating a website/phone application using JQuery Mobile and PhoneGap. I am hoping to add openID support so users can login in with pre-existing accounts. It will be necessary for me to have a database with a few tables to enable me to implement all the core functionality I desire. I haven't really had much experience with frameworks before, the closest thing I have done to this is create a basic website using php that connected to a MySql database stored on the machine that hosted the apache webserver. The interaction with the database won't be complex. I am required to use a java framework for the backend of my application. My question is which java framework is most suitable (flexible and straight forward to learn)?

Any advice you guys can provide is greatly appreciated.

Thanks