GeoLocation - Distance between two Lat/Lons

public class Distance {

public static void main(String[] args) {
Distance d = new Distance();
System.out.println(d.distance(32.9697, -96.80322, 29.46786, -98.53506, 'M') +" Miles !!!");
System.out.println(d.distance(32.9697, -96.80322, 29.46786, -98.53506, 'K') +" KMs !!!");
System.out.println(d.distance(32.9697, -96.80322, 29.46786, -98.53506, 'N') +" Nautical Miles !!!");

}

//Calculate distance between two lat/lons in Miles, KMs, NMs.
private double distance(double lat1, double lon1, double lat2, double lon2, char unit) {
double theta = lon1 - lon2;
double dist = Math.sin(deg2rad(lat1)) * Math.sin(deg2rad(lat2))
+ Math.cos(deg2rad(lat1)) * Math.cos(deg2rad(lat2))
* Math.cos(deg2rad(theta));

dist = Math.acos(dist);
dist = rad2deg(dist);
dist = dist * 60 * 1.1515;
if (unit == 'K') {
dist = dist * 1.609344;
} else if (unit == 'N') {
dist = dist * 0.8684;
}
return (dist);
}


// converts decimal degrees to radians
private double deg2rad(double deg) {
return (deg * Math.PI / 180.0);
}


// converts radians to decimal degrees
private double rad2deg(double rad) {
return (rad * 180.0 / Math.PI);
}

}