stream流操作分组BigDecimal求和，获取最大时间和最小时间

Map<Long, FeeInfoVo> feeInfoVoMap=sortedList.stream().collect(Collectors.groupingBy(
        OasReceBillDto::getFeeId,Collectors.collectingAndThen(Collectors.toList(), m->{
            FeeInfoVo sr=new FeeInfoVo();
            BigDecimal amountAll= m.stream().collect(
                    Collectors.reducing(BigDecimal.ZERO, OasReceBillDto::getReceAmount, BigDecimal::add)
            );
            Optional<OasReceBillDto> min=m.stream().min(Comparator.comparing(OasReceBillDto::getBeginDate));
            Optional<OasReceBillDto> max=m.stream().max(Comparator.comparing(OasReceBillDto::getEndDate));
            sr.setFeeAmount(amountAll);
            sr.setStartDate(min.get().getBeginDate());
            sr.setEndDate(max.get().getEndDate());
            return sr;
        })));