How do I generate a Cartesian product in Java?

Question

I have a number of ArrayList with each ArrayList having objects and each one can have different length. I need to generate permutation like in the

Answer 1

Use nested for loops that would have a loop for every ArrayList as below. I am assuming I have two ArrayLists - intList and stringList. I can have two nested for loops (one for each list) to generate the permutation.

    for(Integer i : intList){
        for (String s : stringList) {
            ...
        }
    }