Download file from sd card to PC

Hi

I have a custom board based on S7G2. It has a SD card configured.

I need to download a file from sd card to PC.I have seen the below forum post.

https://renesasrulz.com/synergy/f/synergy---forum/8600/file-upload-from-s7g2-web-server-to-pc-browser/28015#pi5277=1

In the above post , they are calling a callback function.But in my call back function i have many GET and POST requests.

So i need to receive on server side as GET or POST request in callback function .How to do it.

Please suggest 

Thanks and Regards

Rizwan Syed