... with support for resuming, like download managers do.

I need that my program will download a large file ~ 1,5 GB. (on client side by user wish).
Source link for downloading is usual 7z-file on http-protocol.
I also think to move to WebDAV to use Yandex API.

Are there any ready-to-use solutions?
Any help on list of preferred objects / APIs / other technology usefull for this case will be appreciated.

Thank you.

Regards,
Alex.