The Model Classes

The model classes are business objects. These classes are not specific to any front end or back end, but model the business itself. So when you design them, they should not be designed around what a page requires (e.g. one object that contains a bunch of stuff for the whole page) or what the back end returns (e.g. direct map to proxies). They should be designed around the business model itself.

The SAP proxies will define dates as java.sql.Date. These should be redefined as java.util.Date in the model.