The 2 approaches for data binding are:
Approach 1:
Using Hibernate with Vaadin (http://bit.ly/nyqEDr)
A) Should I use this only if I plan to use objects?
Approach 2:
Rapid Development Using Vaadin and Roo
B ) When should I use this?
C) Would someone please explain when it’s better to use Approach 1 vs Approach 2?
D) I plan to have several forms for users to fill out, convert those data into objects and will need to perform data analysis and statistics. What approach is best suited for this?
Hibernate evolves quite a lot around objects, and so those Java as well. With Hibernate you should have a JavaBean class of every entity in the database. Having the entities helps a lot as then you use data containers like BeanItemContainer where you just give the objects to it and are done. You can of course also use rad jdbc (sql queries and arrays of data as answer) and pass it directly to something like IndexedContainer or use SQLContainer.
I haven’t used Roo personally, but how I’ve understood it, it is about auto-generating a lot of code so you don’t have to make those, like those JavaBeans. I don’t think they are competing really with each others, but I could be wrong.