distance calculator java

1/*::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/
2/*::                                                                         :*/
3/*::  This routine calculates the distance between two points (given the     :*/
4/*::  latitude/longitude of those points). It is being used to calculate     :*/
5/*::  the distance between two locations using GeoDataSource (TM) products   :*/
6/*::                                                                         :*/
7/*::  Definitions:                                                           :*/
8/*::    Southern latitudes are negative, eastern longitudes are positive     :*/
9/*::                                                                         :*/
10/*::  Function parameters:                                                   :*/
11/*::    lat1, lon1 = Latitude and Longitude of point 1 (in decimal degrees)  :*/
12/*::    lat2, lon2 = Latitude and Longitude of point 2 (in decimal degrees)  :*/
13/*::    unit = the unit you desire for results                               :*/
14/*::           where: 'M' is statute miles (default)                         :*/
15/*::                  'K' is kilometers                                      :*/
16/*::                  'N' is nautical miles                                  :*/
17/*::  Worldwide cities and other features databases with latitude longitude  :*/
18/*::  are available at https://www.geodatasource.com                         :*/
19/*::                                                                         :*/
20/*::  For enquiries, please contact sales@geodatasource.com                  :*/
21/*::                                                                         :*/
22/*::  Official Web site: https://www.geodatasource.com                       :*/
23/*::                                                                         :*/
24/*::           GeoDataSource.com (C) All Rights Reserved 2019                :*/
25/*::                                                                         :*/
26/*::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/
27
28import java.util.*;
29import java.lang.*;
30import java.io.*;
31
32class DistanceCalculator
33{
34	public static void main (String[] args) throws java.lang.Exception
35	{
36		System.out.println(distance(32.9697, -96.80322, 29.46786, -98.53506, "M") + " Miles\n");
37		System.out.println(distance(32.9697, -96.80322, 29.46786, -98.53506, "K") + " Kilometers\n");
38		System.out.println(distance(32.9697, -96.80322, 29.46786, -98.53506, "N") + " Nautical Miles\n");
39	}
40
41	private static double distance(double lat1, double lon1, double lat2, double lon2, String unit) {
42		if ((lat1 == lat2) && (lon1 == lon2)) {
43			return 0;
44		}
45		else {
46			double theta = lon1 - lon2;
47			double dist = Math.sin(Math.toRadians(lat1)) * Math.sin(Math.toRadians(lat2)) + Math.cos(Math.toRadians(lat1)) * Math.cos(Math.toRadians(lat2)) * Math.cos(Math.toRadians(theta));
48			dist = Math.acos(dist);
49			dist = Math.toDegrees(dist);
50			dist = dist * 60 * 1.1515;
51			if (unit.equals("K")) {
52				dist = dist * 1.609344;
53			} else if (unit.equals("N")) {
54				dist = dist * 0.8684;
55			}
56			return (dist);
57		}
58	}
59}