IN OIC Merge multiple XML files to a single file

Organization Name (Required - If you are an Oracle Partner, please provide the organization you are logging the idea on behalf of):

Creoal Consulting

Description (Required):

In OIC we have a requirement to merge XML files .

Use Case and Business Need (Required):

We have to extract invoices on a daily basis from Oracle Cloud, validate each invoice against some services on the system we are sending these invoices to, then write the invoice and details to an XML file. Since this is in a loop, an XML file get written and created for each invoice. When we append and create a single file, the XML header tag gets repeated, and the resulting XML file becomes invalid. The system that receives these invoices expects a single XML file with all invoices information in it.