what's a good persistent collections framework for use in java?

Question

By persistent collections I mean collections like those in clojure.

For example, I have a list with the elements (a,b,c). With a normal list, if I add d, my original

Answer 1

I'm surprised nobody mentioned vavr. I use it for a long time now.

http://www.vavr.io

Description from their site:

Vavr core is a functional library for Java. It helps to reduce the amount of code and to increase the robustness. A first step towards functional programming is to start thinking in immutable values. Vavr provides immutable collections and the necessary functions and control structures to operate on these values. The results are beautiful and just work.