List list = new ArrayList();
list.sort(Comparator.comparing("排序的字段"));//升序
list.sort(Comparator.comparing("排序的字段").reversed());//降序
list.sort(Comparator.comparing("字段1").thenComparing("字段2"));//多字段升序
list.sort(Comparator.comparing("字段1").reversed().thenComparing("字段2"));//字段1降序,字段2升序