RestDataSource sample code : SmartGWT working samples using REST with Database CRUD

We've embarked on a GWT project and using SmartGWT -- we found out that the open source version of SmartGWT does NOT come with DataSources that connect to a RDBMS. In order to connect to a RDBMS, we need to extend RestDataSource and implement REST services that provides the CRUD in the format that the RestDataSource expects.

Are there available Java sample source code that use, say, Spring/CXF to implement a REST service (which has CRUD operations in a RDBMS) and the corresponding Client side GWT/SmartGWT code that interacts with the REST Service using RestDataSource ? This will help us meet our impossible deadline!

Thank you,

BR,

~A

This question is very similar to one I've answered previously, SmartGWT RestDataSource. Maybe you'll find some help there too.