java - 给定纬度和经度，如何打印两个城市之间的距离

Question

我是这样开始我的程序的:

 public static void main( String[] args )
         {
   if(args.length < 2)
   {
   System.err.println("Usage: java -jar lab5.jar infile outfile");
   System.exit(99);
   }

   Cruncher dataManipulator = new Cruncher(args[0], args[1]);

   dataManipulator.openFiles();
   dataManipulator.findDistance();
   dataManipulator.writeRecords();
   dataManipulator.closeFiles();
 }
  String oneCity = "British Columbia:Vancouver:49° 17' N:123° 8' W";
        String twoCity = "Ontario:Hamilton:43° 15' N:79° 52' W";
        String[] source;
        String[] rawLatitude;
        String[] rawLongitude;
        int sourceLatDegrees;
        int sourceLatMinutes;

        if(twoCity.matches("Ontario:Hamilton.*")){
                source = twoCity.split(":");
                for(String inspect: source){
                        System.out.printf("%s\n", inspect);
                }
                rawLatitude = source[2].split("\\D+");
                for(String inspect: rawLatitude){
                     System.out.printf("%s\n", inspect);
                }
                sourceLatDegrees = Integer.parseInt(rawLatitude[0]);
                sourceLatMinutes = Integer.parseInt(rawLatitude[1]);
                System.out.printf("source lat degrees %d source lat minutes %d\n", 
                        sourceLatDegrees, sourceLatMinutes);
        }

         double earthRadius = 6371;   // in km
         double distance = Math.acos(Math.sin(Lat1) * Math.sin(Lat2) + 
                 Math.cos(Lat1) * Math.cos(Lat2) *
                 Math.cos(Long2 - Long1)) * earthRadius;

         public static double rad2deg(double rad) {

  return (rad * 180.0 / Math.PI);

} 

 } 

我需要显示一个输出，提示用户输入两个城市和省份名称。它将在屏幕上打印一条消息，说明两个城市之间的距离(以公里为单位)。如果在文件中找不到其中一个城市，您将在屏幕上写入一条错误消息，说明未找到哪个城市，然后默默地结束程序。如果用户两次输入相同的城市和省份名称，那么您的程序应该做一些礼貌和明智的事情。有人可以帮我打印部分代码吗？谢谢。

Answer 1

来自https://www.geodatasource.com/developers/java

class DistanceCalculator
{
    public static void main (String[] args) throws java.lang.Exception
    {
        System.out.println(distance(32.9697, -96.80322, 29.46786, -98.53506, "M") + " Miles\n");
        System.out.println(distance(32.9697, -96.80322, 29.46786, -98.53506, "K") + " Kilometers\n");
        System.out.println(distance(32.9697, -96.80322, 29.46786, -98.53506, "N") + " Nautical Miles\n");
    }

    private static double distance(double lat1, double lon1, double lat2, double lon2, String 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);
    }
}