去除重复元素
HashSet h = new HashSet(holidaysList);
holidaysList.clear();
holidaysList.addAll(h);
以实体类的某个字段去重jdk1.8
holidaysList = holidaysList.stream().collect(Collectors.collectingAndThen(Collectors.toCollection(() ->
new TreeSet<>(Comparator.comparing(TVacation::getHolidayName))), ArrayList::new));
以实体类的某个字段排序jdk1.8
EnteringTibetList = EnteringTibetList.stream().sorted(Comparator.comparing(CountVO::getDepict).reversed())
.collect(Collectors.toList());