Question

I have an interface TestInterface and different classes may implement the interface. Is it possible to have a collection of all the objects which implements the interface? The collection can be created using

LinkedList<TestInterface> store

where store is the name of the collection. But how to keep track of the object creations of classes which implement the TestInterface. And moreover where to keep the collection?

Answer 1

Not knowing what you want this for, it’s hard to tell.

But anyway, yes you can create a collection but in order to track and store references to the TestInterface objects, you must control their creation.

The easiest way would be to have a TestInterfaceFactory (see AbstractFactory pattern), this is also a good place to keep the store collection with the instance references.