Android SQlite to json

I have some data stored inside SQlite at my android application and I want to export it into json file and send it to a server via post HTTP. You can actually see my code in this link - Old question containing my code

After searching the web, I'm only finding samples of doing it the other way around (from json to sqlite). I'll be happy to receive some help/push to the right direction.

Thank you!