无尾差按比例分摊金额算法,加权分摊算法

 一.

public void batchAssignSettlement(BuySettleVo vo) {
        //查询账单下所有一级国内运费费用明细
        List<SettlementCost> settlementCostList = settlementCostModelObjectFactory.select().eq("settlement", vo.getSettlementId()).eq("settleCostItem.name", "国内运费").isNull("uc_settlement_cost").findAll();
        if (ObjectUtil.isNotEmpty(settlementCostList)) {
            //总含税金额
            BigDecimal allTotalAmount = settlementCostList.stream().map(SettlementCost::getTotalAmount).reduce(BigDecimal.ZERO, BigDecimal::add);
            //已分配的金额
            BigDecimal assignedAmount = BigDecimal.ZERO;
            //输入的要分配的含税金额
            BigDecimal needAssignedAmount = vo.getTotalAmount();
            for (int i = 0; i < settlementCostList.size(); i++) {
                SettlementCost settlementCost = settlementCostList.get(i);
                if ((i == settlementCostList.size() - 1 && i != 0) || settlementCostList.size() == 1) {
                    //最后一条减法避免尾差,只有一条全额分摊
                    vo.setTotalAmount(needAssignedAmount.subtract(assignedAmount));
                } else {
                    //按比例分摊
                    BigDecimal assignAmount = needAssignedAmount.multiply(settlementCost.getTotalAmount()).divide(allTotalAmount, 2, RoundingMode.HALF_UP);
                    vo.setTotalAmount(assignAmount);
                    assignedAmount = assignedAmount.add(assignAmount);
                }
                assignSettlement(settlementCost, vo);
            }
        } else {
            throw bizMessage.error("该账单无结算费用:国内运费");
        }
    }

二.

    /**
     * 加权分摊算法
     *
     * @param needAssignedAmount 要分配的金额
     * @param factor             系数
     * @param factorSum          总数
     * @param assignedAmount     已分配金额
     * @param totalSize          总数量
     * @param index              序列(第几条)
     * @param scale              保留小数位
     * @return 要分配的金额*系数/总含税金额
     */
    public static BigDecimal getWeightingShare(BigDecimal needAssignedAmount, BigDecimal factor, BigDecimal factorSum, BigDecimal assignedAmount, int totalSize, int index, int scale) {
        if ((index == totalSize - 1 && index != 0) || totalSize == 1) {
            //最后一条减法避免尾差,只有一条全额分摊
            return needAssignedAmount.subtract(assignedAmount);
        } else {
            //按比例分摊
            return needAssignedAmount.multiply(factor).divide(factorSum, scale, RoundingMode.HALF_UP);
        }
    }

        List<Map<String, Object>> maps = jdbcTemplate.getJdbcTemplate().queryForList(getSql(0, OffsetDateTimeUtil.formatDateTime(beginTime), OffsetDateTimeUtil.formatDateTime(endTime)));
        for (Map<String, Object> map : maps) {
            Object orderId = map.get("ORDER_ID");
            Object sellerId = map.get("SELLER_ID");
            Object buyerId = map.get("BUYER_ID");
            BigDecimal cnySettleTotalAmount = (BigDecimal) map.get("CNY_SETTLE_TOTAL_AMOUNT");
            BigDecimal usdSettleTotalAmount = (BigDecimal) map.get("USD_SETTLE_TOTAL_AMOUNT");
            Party seller = partyModelObjectFactory.find(sellerId);
            Party buyer = partyModelObjectFactory.find(buyerId);
            InternationalOrder internationalOrder = internationalOrderModelObjectFactory.find(orderId);
            BigDecimal netWeight = internationalOrder.getNetWeight();
            List<OrderContainerLine> orderContainerLineList = internationalOrder.getContainers().getValue();
            BigDecimal totalTeu = orderContainerLineList.stream().map(orderContainerLine -> ((BigDecimal) orderContainerLine.getGoods().getRefer().get("uc_teu")).multiply(orderContainerLine.getQty())).reduce(BigDecimal.ZERO, BigDecimal::add);
            //按集装箱箱型做合并
            Map<Thing, List<OrderContainerLine>> groupMap = orderContainerLineList.stream().collect(Collectors.groupingBy(orderContainerLine -> orderContainerLine.getGoods().getRefer()));
            int groupMapSize = groupMap.entrySet().size();
            int i = 0;
            BigDecimal assignedWeight = BigDecimal.ZERO;
            BigDecimal assignedAmountCny = BigDecimal.ZERO;
            BigDecimal assignedAmountUsd = BigDecimal.ZERO;
            for (Thing containerMode : groupMap.keySet()) {
                List<OrderContainerLine> items = groupMap.get(containerMode);
                BigDecimal qty = items.stream().map(OrderContainerLine::getQty).reduce(BigDecimal.ZERO, BigDecimal::add);
                BigDecimal teu = items.stream().map(orderContainerLine -> ((BigDecimal) orderContainerLine.getGoods().getRefer().get("uc_teu")).multiply(orderContainerLine.getQty())).reduce(BigDecimal.ZERO, BigDecimal::add);
                ExportCarrierReport exportCarrierReport = exportCarrierReportModelObjectFactory.create();
                exportCarrierReport.setOrderId(internationalOrder.getId());
                exportCarrierReport.setOrderNo(internationalOrder.getOrderNo());
                exportCarrierReport.getSeller().setValue(seller);
                exportCarrierReport.getBuyer().setValue(buyer);
                exportCarrierReport.setPostDate(ObjectUtil.isNotEmpty(internationalOrder.get("uc_post_date")) ? (OffsetDateTime) internationalOrder.get("uc_post_date") : internationalOrder.getOrderDate());
                exportCarrierReport.setFreightForwarder(internationalOrder.get("uc_is_freight_forwarder"));
                exportCarrierReport.getContainerMode().setValue(containerMode);
                exportCarrierReport.setContainerQty(qty);
                exportCarrierReport.setIncoTerms(internationalOrder.getIncoTerms());
                exportCarrierReport.setTeu(teu);
                exportCarrierReport.getOriginalStation().setValue(internationalOrder.getOriginalStation());
                exportCarrierReport.getDestinationStation().setValue(internationalOrder.getDestinationStation());
                if (totalTeu.compareTo(BigDecimal.ZERO) > 0) {
                    //加权分摊重量/人民币金额/美元金额
                    BigDecimal weight = SettlementUtil.getWeightingShare(netWeight, teu, totalTeu, assignedWeight, groupMapSize, i, 0);
                    assignedWeight = assignedWeight.add(weight);
                    exportCarrierReport.setWeight(weight.divide(new BigDecimal("1000"), 3, RoundingMode.HALF_UP));
                    BigDecimal amountCny = SettlementUtil.getWeightingShare(cnySettleTotalAmount, teu, totalTeu, assignedAmountCny, groupMapSize, i, 2);
                    assignedAmountCny = assignedAmountCny.add(amountCny);
                    exportCarrierReport.setAmountCny(amountCny);
                    BigDecimal amountUsd = SettlementUtil.getWeightingShare(usdSettleTotalAmount, teu, totalTeu, assignedAmountUsd, groupMapSize, i, 2);
                    assignedAmountUsd = assignedAmountUsd.add(amountUsd);
                    exportCarrierReport.setAmountUsd(amountUsd);
                } else {
                    //teu为0则均分
                    BigDecimal weight = SettlementUtil.getWeightingShare(netWeight, BigDecimal.ONE, new BigDecimal(orderContainerLineList.size()), assignedWeight, groupMapSize, i, 0);
                    assignedWeight = assignedWeight.add(weight);
                    exportCarrierReport.setWeight(weight.divide(new BigDecimal("1000"), 3, RoundingMode.HALF_UP));
                    BigDecimal amountCny = SettlementUtil.getWeightingShare(cnySettleTotalAmount, BigDecimal.ONE, new BigDecimal(orderContainerLineList.size()), assignedAmountCny, groupMapSize, i, 2);
                    assignedAmountCny = assignedAmountCny.add(amountCny);
                    exportCarrierReport.setAmountCny(amountCny);
                    BigDecimal amountUsd = SettlementUtil.getWeightingShare(usdSettleTotalAmount, BigDecimal.ONE, new BigDecimal(orderContainerLineList.size()), assignedAmountUsd, groupMapSize, i, 2);
                    assignedAmountUsd = assignedAmountUsd.add(amountUsd);
                    exportCarrierReport.setAmountUsd(amountUsd);
                }
                exportCarrierReport.insert();
                i++;
            }
        }