Matching current Location with Database list of location with in 50 miles

Question

i am trying to work on application , in which i have List of location from database and i want to check Which location from database is near to my current location within few miles like 20 miles and list got refreshed automatically with the refined Location and then send notification to user that you have enter to this location...

I have searched over this and come to know about Geofencing But i did not get it properly.. so please suggest me how should i start working on it ... Any sample , code or link will be helpful

thanks in advance

Answer 1

I have used one function distanceTo to calculate distance between to Locations.

I have coded it for only 100 mtr, you need to change value of distance you want to compare with.

private boolean isMarkerIn100(ArrayList<Model> arrayList) {
        Location locationA = new Location("LocationA");
        locationA.setLatitude(latitude);
        locationA.setLongitude(longitude);

        for (int i = 0; i < arrayList.size(); i++) {
            Location locationB = new Location("LocationB");
            locationB.setLatitude(arrayList.get(i).getLat());
            locationB.setLongitude(arrayList.get(i).getLng());
            if (locationA.distanceTo(locationB) < 100 && arrayList.get(i).getHit() > 4) {
                return false;
            }
        }
        return true;
    }

In above code, latitude and longitude are for my (User's) location (Say locationA) and ArrayList is data from database with lat and lng.