Java Implementation of Haversine Formula for distance calculation between two points

HaversineDistance.java

/**
 * This is the implementation Haversine Distance Algorithm between two places
 * @author ananth
 * R = earth’s radius (mean radius = 6,371km)
 Δlat = lat2− lat1
 Δlong = long2− long1
 a = sin²(Δlat/2) + cos(lat1).cos(lat2).sin²(Δlong/2)
 c = 2.atan2(√a, √(1−a))
 d = R.c
 *
 */

public class HaversineDistance {

/**
 * @param args
 * arg 1- latitude 1
 * arg 2 — latitude 2
 * arg 3 — longitude 1
 * arg 4 — longitude 2
 */
 public static void main(String[] args) {
 // TODO Auto-generated method stub
 final int R = 6371; // Radious of the earth
 Double lat1 = Double.parseDouble(args[0]);
 Double lon1 = Double.parseDouble(args[1]);
 Double lat2 = Double.parseDouble(args[2]);
 Double lon2 = Double.parseDouble(args[3]);
 Double latDistance = toRad(lat2-lat1);
 Double lonDistance = toRad(lon2-lon1);
 Double a = Math.sin(latDistance / 2) * Math.sin(latDistance / 2) + 
 Math.cos(toRad(lat1)) * Math.cos(toRad(lat2)) * 
 Math.sin(lonDistance / 2) * Math.sin(lonDistance / 2);
 Double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
 Double distance = R * c;
 
 System.out.println(“The distance between two lat and long is::” + distance);

}
 
 private static Double toRad(Double value) {
 return value * Math.PI / 180;
 }

}

I suggest to set a more precise Earth's radius value:

public static final double R = 6371.0088; // Earth's radius Km

Fore more reference:
https://en.wikipedia.org/wiki/Earth_radius

For better syntax highlighting:

System.out.println("The distance between two lat and long is: " + distance);

FYI there is a Math.toRadians() method