Question

Suppose I have a CatHerder and he has Cats, when I getCatHerderByID(String id) should I load in the CatHerder and set an arrayList of cats or an arrayList of catIDs?

Answer 1

getCatHerderByID() should be a method which returns an object of type CatHerder, which can have a property catsOwned which will contain a list of IDs, populated by the constructor. In addition, you can have a method on the CatHerder object called getCats() which returns an array of Cat consisting of the IDs in the CatHerder object. You shouldn’t load unnecessary information just because it has a relationship with the information you actually want — in many cases, everything will have a relationship with the data you actually want.