Symmetric difference of two sets in Java

Question

There are two TreeSets in my app:

set1 = {501,502,503,504}
set2 = {502,503,504,505}

I want to get the symmetric difference of thes

Answer 1

use retain all,remove all then addAll to do a union of existing set.

1. intersectionSet.retainAll(set2) // intersectionSet is a copy of set1
2. set1.addAll(set2); // do a union of set1 and set2
3. then remove the duplicates set1.removeAll(intersectionSet);