java - How to calculate the closest co-ordinates to a given point from a client on server side

Question

I have a user current location and a radius which I send to server. I want server to return only locations inside a given radius. (I am not sure how many locations I will have in server's DB)

Application written in Java for android platform and server written in Java.

Edited: Spatial MySQL DB ,Found this very helpful after seeing the answer below.

Answer 1

使用空间数据库，他们可以处理这样的请求。