list对象根据字段去掉重复元素

public static List<NoticeUser> removeDupliById(List<NoticeUser> persons) {
System.out.println("persons.size()"+persons.size());
        Set<NoticeUser> personSet = new TreeSet<>((o1, o2) -> o1.getUserId().compareTo(o2.getUserId()));
        personSet.addAll(persons);
    System.out.println(" return  persons.size()"+persons.size());
        return new ArrayList<>(personSet);
    }