I have this package in my sources.list

deb http://ftp.us.debian.org/debian/ jessie main
deb-src http://ftp.us.debian.org/debian/ jessie main

deb http://security.debian.org/ jessie/updates main contrib
deb-src http://security.debian.org/ jessie/updates main contrib

# jessie-updates, previously known as 'volatile'
deb http://ftp.us.debian.org/debian/ jessie-updates main contrib
deb-src http://ftp.us.debian.org/debian/ jessie-updates main contrib

As you can see, those package are mirrored from US, how do i changed it to another repository region automatically, without change the repo manually ?

I only know like delete the old repo and change it manually to the other region repo, like AU repositories or other repositories.

I know that we can change the repo region, debian uses

http://ftp.<>.debian.org/debian/

But how about repositories which has no other format but like kartolo.sby.datautama.net.id, which is a repo from Indonesia ? how can i change that automatically ? For other repo, could be see here