import org.gavaghan.geodesy.Ellipsoid; //导入依赖的package包/类
/**
 * updates the distance information in the trackpoints of the track object.
 *
 * @param track
 *         Track object to update
 * @throws java.lang.NullPointerException
 *         if track is empty
 */
public static void updateTrackDistances(Track track) {
    Optional.ofNullable(Objects.requireNonNull(track).getTrackPoints()).ifPresent(trackPoints -> {
        GeodeticCalculator geoCalc = new GeodeticCalculator();
        Double distance = 0.0;
        GlobalCoordinates lastCoordinate = null;
        for (TrackPoint trackPoint : trackPoints) {
            trackPoint.setDistance(distance);
            GlobalCoordinates thisCoordinate =
                    new GlobalCoordinates(trackPoint.getLatitude(), trackPoint.getLongitude());
            if (null != lastCoordinate) {
                distance += geoCalc.calculateGeodeticCurve(Ellipsoid.WGS84, lastCoordinate, thisCoordinate)
                        .getEllipsoidalDistance();
            }
            lastCoordinate = thisCoordinate;
        }
    });
}
 

import org.gavaghan.geodesy.Ellipsoid; //导入依赖的package包/类
/**
 * Returns the geodetic distance of two Coordinates in kilometers.
 *
 * @param lat1
 * @param lng1
 * @param lat2
 * @param lng2
 * @return distance in km
 */
private double getDistance(double lat1, double lng1, double lat2, double lng2) {
	// set position 1
	GlobalPosition position1 = new GlobalPosition(lat1, lng1, 0.0);
	// set position 2
	GlobalPosition position2 = new GlobalPosition(lat2, lng2, 0.0);
	// calculate the geodetic measurement
	GeodeticMeasurement geoMeasurement = geoCalc
			.calculateGeodeticMeasurement(Ellipsoid.WGS84, position1,
					position2);
	double p2pKilometers = geoMeasurement.getPointToPointDistance() / 1000.0;
	return p2pKilometers;
}