Spring Roo or Spring Framework with Vaadin? Help meeee...


I have done a small software with Vaadin and now I would like to make better layer for accessing data. What is the best solution for that and how can I start? What is the easiest way to transfer pure Vaadin-project to Spring or Spring Roo project?

I have mySql DB and vaadin project and I am using Eclipse. What is better or worse in Roo compared to Spring Framework or is there even better frameworks to handle datalayer? Is there any reason to use Hibernate (JPA) + Spring or just Spring? Any idea or comments, anything?