获取2个经纬度坐标之间的距离

获取地球 2个经纬度之间的距离
JAVA源码如下：
private double EARTH_RADIUS = 6378.137; //地球半径

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

public double GetDistance(double Lat1,double Lon1,double Lat2,double Lon2 ){
double radLat1 = rad(Lat1);
double radLat2 = rad(Lat2);
double a =radLat1 - radLat2;
double b =rad(Lon1) - rad(Lon2);
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;
BigDecimal bg = new BigDecimal(s);
double f1 = bg.setScale(2, BigDecimal.ROUND_HALF_UP).doubleValue();
return f1;
}
结果保留2位小数 单位为km

SQL源码如下：

lon1: 122.3 lat1: 37.1
lon2: 122.2 lat2: 37.6

select ROUND(
6378.138*2*ASIN(
SQRT(
POW(
SIN(
( (PI()*37.1/180.0)
-
(PI()*37.6/180.0)
)
/2)
,2)
+
COS(
(PI()*37.1/180.0)
)
*
COS(
(PI()*37.6/180.0)
)
*
POW(
SIN(
(
(PI()*122.3/180.0)
-
(PI()*122.2/180.0)
)/2)
,2)
)
),2) as langth;

其中lon1,lon2为经度 而lat1,lat2为纬度  单位为千米