Generate all permutations in Java [duplicate]

Answer 1

Use a recursive function, instead of loops. Each time you call the method should be on a smaller portion of the array and stop when length = 0. This link should help you design your function.

Answer 2

It may or may not be optimal as far as performance goes, but if you're looking for a way to do it with writing relatively little code and having it be clear and maintainable, you want a recursive method rather than nested loops.