That program can calculate the distance between two locations (defined by coordinates-lon+lat-) (one given by user + a lot which can be read from a CSV file). It's based on the haversine formula. https://en.wikipedia.org/wiki/Haversine_formula
Program can generate geohash of these locations. Every location (including the one which given by user) has a radius too. It's used to know the user-given location is including the ones from the file or not(including these radius of course).
All data is calculated from a user input and a CSV file. Now you can add your own csv file. Input form is the next:
Lat, lon, radius
If you choose a non-existing or an illegal file, default csv will be used.
Every data will be sent out into HTML tables (trough JSP) which can be accessible at localhost:8080/geohash
I'm a beginner Java-dev, it's just a training code.