java两个List的交集，并集

java两个List的交集，并集，差异集

public class Test {

    public static void main(String[] args) {

        List<String> list1 = new ArrayList<String>();
        list1.add("1111");
        list1.add("2222");
        list1.add("3333");
        list1.add("4444");
        list1.add("5555");

        List<String> list2 = new ArrayList<String>();
        list2.add("3333");
        list2.add("4444");
        list2.add("6666");

        Test test = new Test();
        List<String> list1_1 = test.deepCloneList(list1);
        list1_1.retainAll(list2); //list1与list2的交集
        System.out.println(list1_1.toString());//[3333, 4444]

        List<String> list1_2 = test.deepCloneList(list1);
        list1_2.removeAll(list2); //list1移除list2的集合
        System.out.println(list1_2.toString());//[1111, 2222, 5555]

        List<String> list2_1 = test.deepCloneList(list2);
        list2_1.removeAll(list1); //list2移除list1的集合
        System.out.println(list2_1.toString());//[6666]

        List<String> list1_3 = test.deepCloneList(list1);
        list1_3.addAll(list2);//list1_3与list2的并集
        System.out.println(list1_3.toString());//[1111, 2222, 3333, 4444, 5555, 3333, 4444, 6666]


    }

    /**
     * 对象深拷贝
     *
     * @param obj
     * @param <T>
     * @return
     */
    public static <T extends Serializable> T deepClone2(T obj) {
        T cloneObj = null;
        try {
            //写入字节流
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            ObjectOutputStream obs = new ObjectOutputStream(out);
            obs.writeObject(obj);
            obs.close();

            //分配内存，写入原始对象，生成新对象
            ByteArrayInputStream ios = new ByteArrayInputStream(out.toByteArray());
            ObjectInputStream ois = new ObjectInputStream(ios);
            //返回生成的新对象
            cloneObj = (T) ois.readObject();
            ois.close();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            //关闭流
        }
        return cloneObj;
    }

    /**
     * 对象深拷贝 try-with-resources写法
     *
     * @param obj
     * @param <T>
     * @return
     */
    public static <T extends Serializable> T deepClone(T obj) {
        T cloneObj = null;
        try (ByteArrayOutputStream out = new ByteArrayOutputStream();
             ObjectOutputStream obs = new ObjectOutputStream(out);
             ByteArrayInputStream ios = new ByteArrayInputStream(out.toByteArray());
             ObjectInputStream ois = new ObjectInputStream(ios);
        ) {
            obs.writeObject(obj);
            cloneObj = (T) ois.readObject();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
        return cloneObj;
    }

    /**
     * List深拷贝
     *
     * @param src
     * @param <T>
     * @return
     */
    public static <T> List<T> deepCloneList2(List<T> src) {
        List<T> dest = null;
        try {
            ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
            ObjectOutputStream out = new ObjectOutputStream(byteOut);
            out.writeObject(src);

            ByteArrayInputStream byteIn = new ByteArrayInputStream(byteOut.toByteArray());
            ObjectInputStream in = new ObjectInputStream(byteIn);
            dest = (List<T>) in.readObject();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            //关闭流
        }
        return dest;
    }

    /**
     * List深拷贝 try-with-resources写法
     *
     * @param src
     * @param <T>
     * @return
     */
    public static <T> List<T> deepCloneList(List<T> src) {
        List<T> dest = null;
        try {
            ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
            ObjectOutputStream out = new ObjectOutputStream(byteOut);
            out.writeObject(src);

            ByteArrayInputStream byteIn = new ByteArrayInputStream(byteOut.toByteArray());
            ObjectInputStream in = new ObjectInputStream(byteIn);
            dest = (List<T>) in.readObject();
        } catch (Exception e) {
            e.printStackTrace();
        }return dest;
    }


}