Android : How to send message from BroadcastReceiver to activity or fragment

I have a receiver, it does call details saving task like storing incoming call, outgoing call etc.. all these details goes to sqlite DB. If my activity is not running, then its fine.

Sometime, when my activity is running, i get some incoming call. the receiver runs & stores data to DB. UI wont get refreshed because it never knows about change in DB.

Here i need to manually tell from receiver that, if activity is running refresh screen. How to implement this process in android.

I'm slightly confused in this part