I am creating a project in which i'm using `Google direction API` to calculate distance between multiple latitude and longitude. But that is showing incorrect. I want to use `Java` for calculating the distance between multiple latitude and longitude.

Here is my java code

```
private static 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);
}

private static double deg2rad(double deg) {
  return (deg * Math.PI / 180.0);
}

private static double rad2deg(double rad) {
  return (rad * 180 / Math.PI);
}

```