Flex/Spring: Working with join table/entity

I have a question regarding mapping and entities/domains with Flex/Spring mapping via BDS. I currently have domains mapped to tables, and I am working off existing code to try and change the logic from web services to work with Blaze.

Now, i came across a value object used previously that mapped to a datagrid, but that value object wasnt a true table entity. Now I spli开发者_高级运维t that value object into two logical ones, MessageItemFormats and MessageItemTypes. Now, that it is split, i have to find a way to work with both of them at the same time. I have a datagrid in the view that maps as a dataProvider to the valueObject. How do I map it to a split set of domains?

I am new to hibernate/Java, so I am not sure how this works from the Flex site of things... How do I join them to get attributes from both entities?