计算地球表面二个点之间的距离

计算地球表面2个点之间的距离
据说是从google earth里提取出来的方法，返回的单位（应该）是公里

private static double EARTH_RADIUS = 6378.137;public static double GetDistance(double lat1, double lng1, double lat2,double lng2) {double radLat1 = Math.toRadians(lat1);double radLat2 = Math.toRadians(lat2);double a = radLat1 - radLat2;double b = Math.toRadians(lng1) - Math.toRadians(lng2);double s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a / 2), 2)+ Math.cos(radLat1) * Math.cos(radLat2)* Math.pow(Math.sin(b / 2), 2)));s = s * EARTH_RADIUS;s = Math.round(s * 10000) / 10000;return s;}