gistfile1.txt

    public double calculateDistance(double lat1,double lng1, double lat2, double lng2)
    {
       double RADIUS_OF_EARTH = 3958.75;
        lat1 = Math.toRadians(lat1);
        lng1 = Math.toRadians(lng1);
        lat2 = Math.toRadians(lat2);
        lng2 = Math.toRadians(lng2);

        double dlon = lng2 - lng1;
        double dlat = lat2 - lat1;

        double a = Math.pow((Math.sin(dlat/2)),2) + Math.cos(lat1) * Math.cos(lat2) * Math.pow(Math.sin(dlon/2),2);

        double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));

        double dist = RADIUS_OF_EARTH * c;

        return dist;