title: Geo Location API and finding user within a radius
body: <p>I have a Java application and I would like to find out the location of a visitor. The API would give me a the zip code of visitor and then based on that zip code, I will find fire a query and get users in my application within 25/50 mile radius.
  Alternatively visitor can type in the zip code of their interest and application should return users withing x mile of radius.
  For the users who are registered in the system, we have only their zip code.
  I have looked around some options but not found the exact solution. I do not want to download the database of zip code and maintain them.
  I do not think Google API support this kind of stuff.</p>