java8list1、list2計算交集並集去重並集

public static void main(String[] args) {


        List<String> list1 = new ArrayList();
        list1.add("1111");
        list1.add("2222");
        list1.add("3333");

        List<String> list2 = new ArrayList();
        list2.add("3333");
        list2.add("4444");
        list2.add("5555");

        // 交集
        List<String> intersection = list1.stream().filter(item -> list2.contains(item)).collect(toList());
        System.out.println("---得到交集 intersection---");
        intersection.parallelStream().forEach(System.out :: println);

        // 差集 (list1 - list2)
        List<String> reduce1 = list1.stream().filter(item -> !list2.contains(item)).collect(toList());
        System.out.println("---得到差集 reduce1 (list1 - list2)---");
        reduce1.parallelStream().forEach(System.out :: println);

        // 差集 (list2 - list1)
        List<String> reduce2 = list2.stream().filter(item -> !list1.contains(item)).collect(toList());
        System.out.println("---得到差集 reduce2 (list2 - list1)---");
        reduce2.parallelStream().forEach(System.out :: println);

        // 並集
        List<String> listAll = list1.parallelStream().collect(toList());
        List<String> listAll2 = list2.parallelStream().collect(toList());
        listAll.addAll(listAll2);
        System.out.println("---得到並集 listAll---");
        listAll.parallelStream().forEach(System.out :: println);

        // 去重並集
        List<String> listAllDistinct = listAll.stream().distinct().collect(toList());
        System.out.println("---得到去重並集 listAllDistinct---");
        listAllDistinct.parallelStream().forEach(System.out :: println);

        System.out.println("---原來的List1---");
        list1.parallelStream().forEach(System.out :: println);
        System.out.println("---原來的List2---");
        list2.parallelStream().forEach(System.out :: println);



    }