Chapter 12 -- Delegating Data Access

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Chapter 12

So far we've designed and developed test stubs for our main business objects. We've also designed and built facade objects. The latter are tightly bound to specific user applications, whereas the main business objects are general and meant for other applications to reuse, one application after another. The main business objects, in fact, form a higher-level layer of infrastructure—an infrastructure built upon business rules and business logic—on top of the more technical one.

Our next task is to design data access for our main business objects. We'll do that by designing separate data access classes. Our plan is to give each main business object access to two data access objects: one for data fetching and one for data modification. Incidentally, in our architecture it's the norm for the kind of main business objects we call entity managers to have two data access objects at their disposal.