Laravel: Prevent direct access of files from public folder

I am stuck on this part of my laravel application, Where I am asked to protect the files from directly accessed via url browser hit. I have a public folder in which in a doc folder is present where all the documents are going to be uploaded. I just need a solution to prevent this where i can access docs directly from my application but any third party visitor can not view my docs (images,pdfs etc..).

I have tried many solutions but its not at all working. I just want to things :- 1. Protect my docs through direct access. 2. Way of implementing it in laravel (via .htaccess)

I know this can be possible through htaccess, but how? Kindly help Please :)

via Chebli Mohamed