使用List数组实现一边遍历一边删除

使用list数组一边遍历一遍删除

public class ListForTest {
    public static void main(String[] args) {
        //List如何一边遍历，一边删除？
        ArrayList<User> userList = Lists.newArrayList(
                new User().setId("A").setName("张三"),
                new User().setId("B").setName("李四"),
                new User().setId("C").setName("王五"),
                new User().setId("D").setName("甲"),
                new User().setId("E").setName("乙"),
                new User().setId("F").setName("丙")
        );
        userList.add(new User("F", "丁"));
        System.out.println(userList + "原数据");
        Map<String, String> map = userList.stream().collect(Collectors.toMap(User::getId, User::getName, (k1, k2) -> k1));
        System.out.println("去重后的数据"+map);
        //map转对象
        JSONArray jsonArray = new JSONArray();
        jsonArray.add(map);
        List<User> users = jsonArray.toJavaList(User.class);
        System.out.println("map转list<user>结果为: "+users);
        //错误方法
//        test1(userList);
        //使用Iterator的remove()方法
//        iteratorRemove(userList);
        //使用for循环正序遍历
//        ascForRemove(userList);
        //使用for循环倒序遍历
//        descForRemove(userList);
        //jdk1.8 方法 List.removeIf()
//        jdk8Remove(userList);
    }

    private static void jdk8Remove(ArrayList<User> userList) {
        userList.removeIf(user -> "乙".equals(user.getName()));
        System.out.println(userList + "jdk1.8 方法 List.removeIf(), 删除乙");
    }

    private static void descForRemove(ArrayList<User> userList) {
        for (int i = userList.size() - 1; i >= 0; i--) {
            String name = userList.get(i).getName();
            if ("甲".equals(name)) {
                userList.remove(i);
            }
        }
        System.out.println(userList + "使用for循环倒序遍历, 删除甲");
    }

    private static void ascForRemove(ArrayList<User> userList) {
        for (int i = 0; i < userList.size(); i++) {
            String name = userList.get(i).getName();
            if ("王五".equals(name)) {
                userList.remove(i);
                i--;
            }
        }
        System.out.println(userList + "使用for循环正序遍历, 删除王五");
    }

    private static void iteratorRemove(ArrayList<User> userList) {
        Iterator<User> iterator = userList.iterator();
        while (iterator.hasNext()) {
            User next = iterator.next();
            if ("李四".equals(next.getName())) {
                iterator.remove();
            }
        }
        System.out.println(userList + "使用Iterator的remove()方法,删除李四");
    }

    private static void test1(ArrayList<User> userList) {
        for (User user : userList) {
            if ("张三".equals(user.getName())) {
                userList.remove(user);
            }
        }
        System.out.println(userList);
    }
}