package com.boying.common.util;

public class LngLatUtil {

    private static final double EARTH_RADIUS = 6378.137; // 地球半径

    private static double rad(double d) {
        return d * Math.PI / 180.0; // 计算弧长
    }

    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 * 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 = s * 1000; // 换算成米
        return s;
    }

    public static double getDistance(String lat1, String lng1, String lat2,
                                     String lng2) {

        return getDistance(Double.parseDouble(lat1), Double.parseDouble(lng1),
                Double.parseDouble(lat2), Double.parseDouble(lng2));
    }

}