I try to create a XRechnung xml-file with the Mustangproject and validate it.
error is currently: Item net price MUST equal (Gross price – Allowance amount) when gross price is provided.
Path: /rsm:CrossIndustryInvoice/rsm:SupplyChainTradeTransaction[1]/ram:IncludedSupplyChainTradeLineItem[1]/ram:SpecifiedLineTradeAgreement[1]/ram:GrossPriceProductTradePrice[1]

But i don’t get how i set netprice and grossPrice, and how it affects the result.

This is the loop that processes all invoiceLines (1) already read from a JSON.

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) {
                                // TODO Auto-generated method stub
                                return new BigDecimal(
                                        invoiceLine.invoiceLineAllowances.invoiceLineAllowanceAmount.getContent());
                            }

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

                            @Override
                            public boolean isCharge() {
                                // TODO Auto-generated method stub
                                return false;
                            }

                            @Override
                            public String getReason() {
                                // TODO Auto-generated method stub
                                return invoiceLine.invoiceLineAllowances.invoiceLineAllowanceReason.getContent();
                            }

                        });}

Here is the XML-Part with the amounts, looks right to me

<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>

I wanted to Validate the XRechnung-XML with https://www.epoconsulting.com/erechnung-sap/xrechnung-validator or any other validator. Error: Item net price MUST equal (Gross price – Allowance amount) when gross price is provided.