private List<T> deWeight(List<T> list, String type){ if (CollectionUtils.isEmpty(list)) return null; while (StringUtils.isNotBlank(type)) { switch (type) { case "1": for (int i = 0; i < list.size(); i++) { for (int j = i + 1; j < list.size(); j++) { if (list.get(i).equals(list.get(j))) { list.remove(j); } } } case "2": List<T> newList = new ArrayList<>(); for (T obj : list) { if (!newList.contains(obj)) { newList.add(obj); } } list.clear(); list.addAll(newList); case "3": HashSet hashSet = new HashSet(list); list.clear(); list.addAll(hashSet); case "4": TreeSet treeSet = new TreeSet(list); list.clear(); list.addAll(treeSet); case "5": list.stream().distinct().collect(Collectors.toList()); case "6": Iterator iterator = list.iterator(); while (iterator.hasNext()) { Object t = iterator.next(); Iterator iterator1 = list.iterator(); while (iterator1.hasNext()) { Object ts = iterator1.next(); if (t == ts) iterator.remove(); } } case "7": //快慢指针的模式，汇合中的数据得是有程序的，否则去重会有问题慎用 int slowIndex = 0; for (int fastIndex = 1; fastIndex < list.size(); fastIndex++) { if (list.get(slowIndex) != list.get(fastIndex)) { slowIndex ++; list.set(slowIndex, list.get(fastIndex)); } } list.subList(0,slowIndex); default: list = list; } } return list; }