java 8两个List集合取交集、并集、差集、去重并集

public static void main(String[] args) {
    
    

ArrayList<String> listA = CollectionUtil.toList("a", "b", "c", "d", "e");
ArrayList<String> listB = CollectionUtil.toList( "b", "c", "d", "e", "f");
System.out.println("listA = " + listA);
System.out.println("listB = " + listB);

// listA和listB的差集（listA - listB）
List<String> collect = listA.stream().filter(item -> !listB.contains(item)).collect(Collectors.toList());
System.out.println("listA - listB的差集 = " + collect);

// listA和listB的差集（listB - listA）
List<String> collect1 = listB.stream().filter(item -> !listA.contains(item)).collect(Collectors.toList());
System.out.println("listB - listA的差集 = " + collect1);

// listA和listB交集
List<String> intersection = listA.stream().filter(listB::contains).collect(Collectors.toList());
System.out.println("listA和listB交集 = " + intersection);

// listA和listB并集（不去重）
listA.addAll(listB);
System.out.println("listA和listB并集 = " + listA);

// listA和listB并集（去重）
List<String> distinctList = listA.stream().distinct().collect(Collectors.toList());
System.out.println("listA和listB去重并集 = " + distinctList);
}
}