I'm searching for a library (preferably generic) that generates iterable combinations and permutations of data contained in collections. Cartesian product would also be nice.
The best way of describing what I want would be "itertools for Java".
itertools does much more than just combinations and permutations, so (while it would surely be nice to have all of itertools when coding Java;-) you can get away with much less.
For example, for permutations, see here; for combinations, here (both classes are from the same author).