给出两点经纬度算距离

<span style="font-size:14px;font-weight: normal;">
private static final  double EARTH_RADIUS = 6378137;//赤道半径(单位m)

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

/**
* 基于余弦定理求两经纬度距离
* @param lon1 第一点的精度
* @param lat1 第一点的纬度
* @param lon2 第二点的精度
* @param lat3 第二点的纬度
* @return 返回的距离，单位km
* */
public static double LantitudeLongitudeDist(double lon1, double lat1,double lon2, double lat2) {
double radLat1 = rad(lat1);
double radLat2 = rad(lat2);

double radLon1 = rad(lon1);
double radLon2 = rad(lon2);

if (radLat1 < 0)
radLat1 = Math.PI / 2 + Math.abs(radLat1);// south
if (radLat1 > 0)
radLat1 = Math.PI / 2 - Math.abs(radLat1);// north
if (radLon1 < 0)
radLon1 = Math.PI * 2 - Math.abs(radLon1);// west
if (radLat2 < 0)
radLat2 = Math.PI / 2 + Math.abs(radLat2);// south
if (radLat2 > 0)
radLat2 = Math.PI / 2 - Math.abs(radLat2);// north
if (radLon2 < 0)
radLon2 = Math.PI * 2 - Math.abs(radLon2);// west
double x1 = EARTH_RADIUS * Math.cos(radLon1) * Math.sin(radLat1);
double y1 = EARTH_RADIUS * Math.sin(radLon1) * Math.sin(radLat1);
double z1 = EARTH_RADIUS * Math.cos(radLat1);

double x2 = EARTH_RADIUS * Math.cos(radLon2) * Math.sin(radLat2);
double y2 = EARTH_RADIUS * Math.sin(radLon2) * Math.sin(radLat2);
double z2 = EARTH_RADIUS * Math.cos(radLat2);

double d = Math.sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2)+ (z1 - z2) * (z1 - z2));
//余弦定理求夹角
double theta = Math.acos((EARTH_RADIUS * EARTH_RADIUS + EARTH_RADIUS * EARTH_RADIUS - d * d) / (2 * EARTH_RADIUS * EARTH_RADIUS));
double dist = theta * EARTH_RADIUS;
return dist;
}
</span>