Copying sets Java

Another way to do this is to use the copy constructor:

Collection<E> oldSet = ...
TreeSet<E> newSet = new TreeSet<E>(oldSet);

Or create an empty set and add the elements:

Collection<E> oldSet = ...
TreeSet<E> newSet = new TreeSet<E>();
newSet.addAll(oldSet);

Unlike clone these allow you to use a different set class, a different comparator, or even populate from some other (non-set) collection type.