经纬度计算亮点之间的距离

public static double getDistatce(double lon1, double lat1, double lon2,  double lat2) {
    double R = 6371;
    double distance = 0.0;
    double dLat = (lat2 - lat1) * Math.PI / 180;
    double dLon = (lon2 - lon1) * Math.PI / 180;
    double a = Math.sin(dLat / 2) * Math.sin(dLat / 2)
            + Math.cos(lat1 * Math.PI / 180)
            * Math.cos(lat2 * Math.PI / 180) * Math.sin(dLon / 2)
            * Math.sin(dLon / 2);
    distance = (2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a))) * R;
    return distance;
}
作为一个静态方法，可以随时调用，用处较少，可以直接放在要用的类中