Java: how to transform from List to Map without iterating

Question

I have a list of objects that I need to transform to a map where the keys are a function of each element, and the values are lists of another function of each element. Effec

Answer 1

I don't know why you don't want to iterate. JDK does not support transform, but you can implement it yourself.

If you are worried about the performance, even if JDK had supported it, it would have also iterated it.