Pull the data from SAP BW System and process in java

We have a requirement to develop an application that pulls the data from SAP BW system and display it on a Flex chart.

The Flex guy wants the data in the XML format. Am the middleWare guy who sits in between the SAP BW and the flex. I need to pull the data from SAP BW system and feed the flex components in XML.

Question: How do I need to pull the data from SAP BW System, process it and convert to XML.?

Initial thoughts: 1. The SAP BW System generates a CSV file. Process that CSV file and generate the XML. Basically am a Java guy, so am thinking it as a JAVA WEB-SERVICE.

Any other thoughts, better approaches, please?

Thank You :)