Hi For my STRUTS PROJECT....I have to connect to a database using DAOs. I used two layerse called DAO (data access objects) and "service" layer where business logic is reside.i used DTO (datatarnsfer objects) for transfer data from frountend to backend.
later i add another layer between frount and service layer called delegate layer to redue coupling.
my problom is what kind of methods i have to use in these layerse. do i have to use more specific methods at delegate layer, and fewer and 'more general' ones at the DAO or othr way round?
my rule of thumb is that it gets more specific the further you get from the persistence layer. so the DAO layer might have a getAllWidgets() method, and the service layer have getAllGreenWidgets() and getAllRedWidgets(). the delegate layer shouldn't have any finer granularity than the service layer,it's job is to just, er, delegate, yes?