Is there anything bad in declaring nested class inside interface in java?

I think it looks nice. It clearly signals that the SearchCriteria is intended for use with ProductService s specifically.

I would encourage you to use classes when you have methods that may require more or less nullable arguments; it gives you the ability to provide whatever you need without having to call a method like.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.