Mustangproject生成XRechnung时价格校验失败问题求助

错误信息 #

当提供Gross price时，Item net price必须等于(Gross price - Allowance amount)，错误路径为/rsm:CrossIndustryInvoice/rsm:SupplyChainTradeTransaction[1]/ram:IncludedSupplyChainTradeLineItem[1]/ram:SpecifiedLineTradeAgreement[1]/ram:GrossPriceProductTradePrice[1]

当前代码实现 #

for (jsonMapper.InvoiceLine invoiceLine : invoiceData.invoiceLines) {
    String description = invoiceLine.itemInformation.itemDescription.getContent();
    String name = invoiceLine.itemInformation.itemName.getContent();
    String unit = invoiceLine.invoicedQuantityUnitOfMeasureCode.getContent();
    BigDecimal vATPercent = new BigDecimal(invoiceLine.lineVatInformation.invoicedItemVatRate.getContent());

    Double netPrice = invoiceLine.priceDetails.itemNetPrice.getContent();
    Double quantity = invoiceLine.invoicedQuantity.getContent();

    invoice.addItem(new Item(new BigDecimal(netPrice), new BigDecimal(quantity), 
            new Product(description, name, unit, vATPercent))).addAllowance(new IZUGFeRDAllowanceCharge() {

        @Override
        public BigDecimal getTotalAmount(IAbsoluteValueProvider trans) {
            return new BigDecimal(
            invoiceLine.invoiceLineAllowances.invoiceLineAllowanceAmount.getContent());
        }

        @Override
        public BigDecimal getTaxPercent() {
            return new BigDecimal(invoiceLine.invoiceLineAllowances.invoiceLineAllowancePercentage.getContent());
        }

        @Override
        public boolean isCharge() {
            return false;
        }

        @Override
        public String getReason() {
            return invoiceLine.invoiceLineAllowances.invoiceLineAllowanceReason.getContent();
        }
    });
}

生成的XML片段 #

行项目价格部分 #

<ram:SpecifiedLineTradeAgreement>
        <ram:GrossPriceProductTradePrice>
          <ram:ChargeAmount>40.0000</ram:ChargeAmount>
          <ram:BasisQuantity unitCode="EA">1.0000</ram:BasisQuantity>
        </ram:GrossPriceProductTradePrice>
        <ram:NetPriceProductTradePrice>
          <ram:ChargeAmount>40.0000</ram:ChargeAmount>
          <ram:BasisQuantity unitCode="EA">1.0000</ram:BasisQuantity>
        </ram:NetPriceProductTradePrice>
      </ram:SpecifiedLineTradeAgreement>

结算汇总部分 #

<ram:SpecifiedTradeSettlementHeaderMonetarySummation>
    <ram:LineTotalAmount>400.00</ram:LineTotalAmount>
    <ram:ChargeTotalAmount>0.00</ram:ChargeTotalAmount>
    <ram:AllowanceTotalAmount>50.00</ram:AllowanceTotalAmount>
    <ram:TaxBasisTotalAmount>350.00</ram:TaxBasisTotalAmount>
    <ram:TaxTotalAmount currencyID="EUR">71.00</ram:TaxTotalAmount>
    <ram:GrandTotalAmount>421.00</ram:GrandTotalAmount>              
    <ram:TotalPrepaidAmount>0.00</ram:TotalPrepaidAmount>
    <ram:DuePayableAmount>421.00</ram:DuePayableAmount>
</ram:SpecifiedTradeSettlementHeaderMonetarySummation>

问题分析与解决方案 #

问题根源 #

从XML可以看出，单条行项目的GrossPrice和NetPrice都是40.00，但结算汇总里总Allowance是50.00（对应10个单位的话，单单位Allowance是5.00），这就导致GrossPrice - AllowanceAmount != NetPrice，违反了XRechnung的强制校验规则。

核心规则说明 #

XRechnung要求：当同时提供行项目的GrossPrice和Allowance时，必须满足单单位NetPrice = 单单位GrossPrice - 单单位AllowanceAmount。

Mustangproject框架中，Item构造器的第一个参数是单单位GrossPrice，添加Allowance后，框架会自动计算并生成正确的NetPrice。你之前的错误是直接传入了NetPrice作为GrossPrice，导致价格逻辑不匹配。

修正代码 #

假设JSON中的itemNetPrice是折扣后的净价，先计算单单位的Allowance，再推导GrossPrice，代码调整如下：

for (jsonMapper.InvoiceLine invoiceLine : invoiceData.invoiceLines) {
    String description = invoiceLine.itemInformation.itemDescription.getContent();
    String name = invoiceLine.itemInformation.itemName.getContent();
    String unit = invoiceLine.invoicedQuantityUnitOfMeasureCode.getContent();
    BigDecimal vATPercent = new BigDecimal(invoiceLine.lineVatInformation.invoicedItemVatRate.getContent());

    Double netPriceDouble = invoiceLine.priceDetails.itemNetPrice.getContent();
    Double quantityDouble = invoiceLine.invoicedQuantity.getContent();
    BigDecimal quantity = new BigDecimal(quantityDouble);
    
    // 获取当前行项目的总折扣金额
    BigDecimal lineAllowanceTotal = new BigDecimal(
        invoiceLine.invoiceLineAllowances.invoiceLineAllowanceAmount.getContent());
    // 计算单单位折扣金额（保留4位小数，避免精度问题）
    BigDecimal unitAllowance = lineAllowanceTotal.divide(quantity, 4, RoundingMode.HALF_UP);
    // 推导单单位GrossPrice：净价 + 单单位折扣
    BigDecimal grossPrice = new BigDecimal(netPriceDouble).add(unitAllowance);

    // 创建Item时传入GrossPrice，框架会自动计算NetPrice
    invoice.addItem(new Item(grossPrice, quantity, 
            new Product(description, name, unit, vATPercent))).addAllowance(new IZUGFeRDAllowanceCharge() {

        @Override
        public BigDecimal getTotalAmount(IAbsoluteValueProvider trans) {
            return lineAllowanceTotal;
        }

        @Override
        public BigDecimal getTaxPercent() {
            return new BigDecimal(invoiceLine.invoiceLineAllowances.invoiceLineAllowancePercentage.getContent());
        }

        @Override
        public boolean isCharge() {
            return false;
        }

        @Override
        public String getReason() {
            return invoiceLine.invoiceLineAllowances.invoiceLineAllowanceReason.getContent();
        }
    });
}

验证结果 #

修正后生成的行项目XML会变为：

<ram:SpecifiedLineTradeAgreement>
    <ram:GrossPriceProductTradePrice>
        <ram:ChargeAmount>45.0000</ram:ChargeAmount>
        <ram:BasisQuantity unitCode="EA">1.0000</ram:BasisQuantity>
    </ram:GrossPriceProductTradePrice>
    <ram:NetPriceProductTradePrice>
        <ram:ChargeAmount>40.0000</ram:ChargeAmount>
        <ram:BasisQuantity unitCode="EA">1.0000</ram:BasisQuantity>
    </ram:NetPriceProductTradePrice>
</ram:SpecifiedLineTradeAgreement>

此时45.00 - 5.00 = 40.00，完全符合校验规则，同时结算汇总的数值也会保持逻辑一致。

内容的提问来源于stack exchange，提问作者Jonas Stengel