This code write a text internal table in a spool then convert it to pdf and download it to presentation server.
So you want to upload a PDF and convert it to a flat text itab, you can upload a pdf with GUI_UPLOAD but AFAIK SAP has no reverse-tool to pdf to extract text. you could look at ADS and some web tools (Google on convert pdf to text) to extract data from a pdf.
Regards,
Raymond