根据经纬度计算距离

app嵌入百度地图或者高德地图时经常会用到根据经纬度计算距离的方法：

/** * 根据经纬度计算距离的工具类 * Created by leven on 2016/10/8. */

public class Distance {
    
    private static final double EARTH_RADIUS = 6378137.0;

    // 返回单位是米
    public static double getDistance(double longitude1, double latitude1, double longitude2, double latitude2) {
        double Lat1 = rad(latitude1);
        double Lat2 = rad(latitude2);
        double a = Lat1 - Lat2;
        double b = rad(longitude1) - rad(longitude2);
        double s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a / 2), 2)
                + Math.cos(Lat1) * Math.cos(Lat2)
                * Math.pow(Math.sin(b / 2), 2)));
        s = s * EARTH_RADIUS;
        s = Math.round(s * 10000) / 10000;
        return s;
    }

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