jdk1.8新特性

public static void main(String[] str){
       List<Integer> list = new ArrayList<>();
       list.add(1);
        list.add(4);
        list.add(3);
        list.add(5);
        list.add(15);
        list.add(10);

        list.sort((o1, o2) -> o2.compareTo(o1));

        Map<String,Integer> map = Maps.newHashMap();
        map.put("张三",98);
        map.put("李四",68);
        map.put("王五",88);
        map.put("赵六",91);
        map.put("马七",90);

        List<Map.Entry<String,Integer>> listMap = map.entrySet().stream().collect(Collectors.toList());
        listMap.sort((o1, o2) -> o1.getValue().compareTo(o2.getValue()));
      System.out.println(listMap);
    }


    List<AccountantGroup> tempGroups = accountantGroups.stream()
                    //过滤掉不匹配的分组，depId, ouCode, categoryCode
                    .filter(accountantGroup -> hasMatchedGroupWork(accountantGroup.getAccountantGroupWork(), claimHeadDto))
                    //过滤掉已达最大处理的分组
                    .filter(accountantGroup -> getMaxGroup(accountantGroup, map))
                    .collect(toList());
List<AccountantGroup> result;

AccountantGroup accountantGroup = Optional.ofNullable(result)
                .orElse(new ArrayList<>())
                .stream()
                .findFirst()
                .orElse(null);

List<Integer> stringList = list.stream().map(AccountantCrew::getCrewEmpId).collect(Collectors.toList());