How to mass upload from a spreadsheet file into an SAP Fiori app in SAP BTP ABAP Environment Part 1

Part 1 of a three-part series on mass-uploading records from a spreadsheet into a RAP business object in the SAP BTP ABAP environmentSAP BTP ABAP environmentserviceSAP's ABAP runtime on BTP: ABAP systems developed in the ABAP Cloud model on SAP HANA Cloud, for cloud apps, OData services and side-by-side extensions of SAP S/4HANA.sap official, btp, using the XCO XLSX module to parse an uploaded Excel file without any open-source library. It reads a named worksheet by its column-and-row coordinates into an internal table through the row-stream operation, then creates or updates records with the EML MODIFY ENTITIES statement, and reserves the Fiori elements custom-action wiring and the download/template generation for Parts 2 and 3.