Java Plum or Black Plum

Hello!
Busy bee here as always. How's everyone?
It's been more than a week since I posted here due to hectic sched.
Anyways, I jusy want to share you this fruit I have eaten few days ago. There is a small tree of this fruit in front of my house and it has a lot of fruits right now which children love to get.
This has been known that good for people who have diabetes and diarrhea. Boiling it leaves with some tree skin peel is very good to cure diarrhea, while eating it fruit for diabetic person.
Have you encounter this fruit in your place?