如何最好地比较Java中的两个集合并采取行动？

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

List<String> list1 = new ArrayList<>();
List<String> list2 = new ArrayList<>();

list1.add("A");
list1.add("B");
list1.add("C");

list2.add("B");
list2.add("C");
list2.add("D");

Set<String> set1 = new HashSet<>(list1);
Set<String> set2 = new HashSet<>(list2);

Set<String> intersection = new HashSet<>(set1);
intersection.retainAll(set2);

Set<String> union = new HashSet<>(set1);
union.addAll(set2);

Set<String> difference1 = new HashSet<>(set1);
difference1.removeAll(set2);

Set<String> difference2 = new HashSet<>(set2);
difference2.removeAll(set1);

List<String> resultList = new ArrayList<>(intersection);