public static double getDistance(double lat1, double lng1, double lat2, double lng2) {
		double radLat1 = rad(lat1);
		double radLat2 = rad(lat2);
		double a = radLat1 - radLat2;
		double b = rad(lng1) - rad(lng2);
		double s = 2.0D * Math.asin(Math.sqrt(Math.pow(Math.sin(a / 2.0D), 2.0D)
				+ Math.cos(radLat1) * Math.cos(radLat2) * Math.pow(Math.sin(b / 2.0D), 2.0D)));
		s *= EARTH_RADIUS;
		s = Math.round(s * 10000.0D) / 10000.0D;
		s *= 1000.0D;
		return s;
	}
原文:https://www.cnblogs.com/xianz666/p/13065918.html