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

Set s1 = new HashSet();
    Set s2 = new HashSet();
    s1.add("a");
    s1.add("b");
    s2.add("b");
    s2.add("c");
    Set s3 = new HashSet(s1);
    s1.removeAll(s2);
    s2.removeAll(s3);
    s1.addAll(s2);
    System.out.println(s1);

output of s1 : [a,c]