java两个List的交集，并集

使用apache的CollectionUtils工具类(推荐)

public static void main(String[] args) {

    String[] arrayA = new String[] { "1", "2", "3", "4"};
    String[] arrayB = new String[] { "3", "4", "5", "6" };
    List<String> listA = Arrays.asList(arrayA);
    List<String> listB = Arrays.asList(arrayB);

    //1、并集 union
    System.out.println(CollectionUtils.union(listA, listB));
    //输出: [1, 2, 3, 4, 5, 6]

    //2、交集 intersection
    System.out.println(CollectionUtils.intersection(listA, listB));
    //输出:[3, 4]

    //3、交集的补集（析取）disjunction
    System.out.println(CollectionUtils.disjunction(listA, listB));
    //输出:[1, 2, 5, 6]

    //4、差集（扣除）
    System.out.println(CollectionUtils.subtract(listA, listB));
    //输出:[1, 2]
}