java List根据属性去重，排序

public class demoTest {

    @Test
    public void text()
    {
        List list=new ArrayList<>();
        UserBean userBean=new UserBean();
        userBean.setPassword("123456");
        userBean.setUsername("张三");
        list.add(userBean);
        UserBean userBean1=new UserBean();
        userBean1.setPassword("123456");
        userBean1.setUsername("李四");
        list.add(userBean1);
        UserBean userBean2=new UserBean();
        userBean2.setPassword("123456");
        userBean2.setUsername("李四");
        list.add(userBean2);

        List removeDuplicateUser = removeDuplicateUser(list);

        
        for(UserBean data : removeDuplicateUser){
            System.out.println(data.getUsername() + ":" + data.getPassword());
        }
        List list1 = sortUser(removeDuplicateUser);
        for(UserBean data : list1){
            System.out.println(data.getUsername() + ":" + data.getPassword());
        }

    }

    
    private static List removeDuplicateUser(List list) {
        Set set = new TreeSet (new Comparator () {
            @Override
            public int compare(UserBean a, UserBean b) {
                // 字符串则按照asicc码升序排列
                return a.getUsername().compareTo(b.getUsername());
            }
        });

        set.addAll(list);
        return new ArrayList(set);
    }

    
    private static List sortUser(List list) {
        Comparator comparator = Collator.getInstance(Locale.CHINESE);
        Collections.sort(list, new Comparator() {
            @Override
            public int compare(UserBean o1, UserBean o2) {
                return comparator.compare(o1.getUsername(), o2.getUsername());
            }
        });
        return list;
    }
}