/**  * 计算两点之间距离  * @param _lat1 - start纬度  * @param _lon1 - start经度  * @param _lat2 - end纬度  * @param _lon2 - end经度  * @return km(四舍五入)  */ public static double getDistance(double _lat1,double _lon1, double _lat2,double _lon2){  double lat1 = (Math.PI/180)*_lat1;  double lat2 = (Math.PI/180)*_lat2;  double lon1 = (Math.PI/180)*_lon1;  double lon2 = (Math.PI/180)*_lon2;  //地球半径  double R = 6378.1;  double d =  Math.acos(Math.sin(lat1)*Math.sin(lat2)+Math.cos(lat1)*Math.cos(lat2)*Math.cos(lon2-lon1))*R;  return new BigDecimal(d).setScale(4,BigDecimal.ROUND_HALF_UP).doubleValue(); } public static void main(String[] args) {  System.out.println(getDistance(45.73990, 126.55893,45.73876, 126.55037)); }