根據經緯度得到兩點距離

    //根據經緯度查詢兩地距離
    private static double rad(double d) {
        return d * Math.PI / 180.0;
    }
    private static double EARTH_RADIUS = 6378.137;
    //地球半徑
    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 distance = 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)));
        distance = distance * EARTH_RADIUS;
        distance = Math.round(distance * 10000d) / 10000d;
        distance=distance*1000;
        return distance;

    }