Is there any benefit in implementing a interface in a subclass even though the superclass implements the same interface

Question

When I was seeing the declaration of ArrayList

class ArrayList extends AbstractList
    implements List, RandomAccess         


        

Answer 1

Totally unnecessary. I wouldn't do it at all.

It's unclear why they did that by then. But by now apparently it's a mistake, since everybody is surprised by it when they first notice this odd redundancy.