Java ArrayList of ? extends Interface

Question

I have a group of classes that all implement a validation interface which has the method isValid(). I want to put a group of objects--all of different classes--

Answer 1

You can use:

List myValidationObjects = new ArrayList<>();           // Java 7
List myValidationObjects = new ArrayList(); // pre Java 7

Now you can add any instance of a class that implements Validation to that list.