seo优化多少钱免费网站seo优化

目录：

1. 获取AB连线与正北方向的角度
2. 求距离此点一定距离、一定夹角的点经纬度
3. 判断point点 在线段startPoint-etartPoint的左侧或者右侧
4. 米转换为弧度
5. 弧度转换为米

定义Point点

public class LatLngPoint {final static double RC = 6378137;final static double RJ = RC;double longitude, latitude;double radLongitude, radLatitude;double Ec;double Ed;static final String LatLngPointString = "%.6f:%.6f";public LatLngPoint(double longitude, double latitude) {this.longitude = longitude;this.latitude = latitude;radLongitude = this.longitude * Math.PI / 180.;radLatitude = this.latitude * Math.PI / 180.;Ec = RJ + (RC - RJ) * (90. - latitude) / 90.;Ed = Ec * Math.cos(radLatitude);}public String getString() {return String.format(LatLngPointString, longitude, latitude);}
}

import com.vividsolutions.jts.algorithm.Angle;
import com.vividsolutions.jts.geom.Coordinate;
import org.locationtech.spatial4j.distance.DistanceUtils;import java.math.BigDecimal;public class LatLngAngleUtil {/*** 获取AB连线与正北方向的角度* * @param startPoint*            A点的经纬度* @param endPoint*            B点的经纬度* @return AB连线与正北方向的角度（0~360）*/public static double getAngleByTwoPoint(LatLngPoint startPoint, LatLngPoint endPoint) {double dx = (endPoint.radLongitude - startPoint.radLongitude) * startPoint.Ed;double dy = (endPoint.radLatitude - startPoint.radLatitude) * startPoint.Ec;double angle = 0.0;angle = Math.atan(Math.abs(dx / dy)) * 180. / Math.PI;double dLo = endPoint.longitude - startPoint.longitude;double dLa = endPoint.latitude - startPoint.latitude;if (dLo > 0 && dLa <= 0) {angle = (90. - angle) + 90;} else if (dLo <= 0 && dLa < 0) {angle = angle + 180.;} else if (dLo < 0 && dLa >= 0) {angle = (90. - angle) + 270;}return angle;}/*** 求距离此点一定距离、一定夹角的点经纬度* * @param distance*            两点之间的距离 单位 m* @param angle*            两点连线与正北方向的夹角（0~360）* @return 算出的点的经纬度*/public static LatLngPoint getLatLngPointByDistanceAndAngle(LatLngPoint startPoint,double distance, double angle) {double dx = distance * Math.sin(Math.toRadians(angle));double dy = distance * Math.cos(Math.toRadians(angle));double bjd = new BigDecimal((dx / startPoint.Ed + startPoint.radLongitude) * 180. / Math.PI).setScale(7, BigDecimal.ROUND_HALF_UP).doubleValue();double bwd = new BigDecimal((dy / startPoint.Ec + startPoint.radLatitude) * 180. / Math.PI).setScale(7, BigDecimal.ROUND_HALF_UP).doubleValue();return new LatLngPoint(bjd, bwd);}/*** 判断point点 在线段startPoint-etartPoint的左侧或者右侧* @param point 需要判断的点* @param startPoint  线段开始点* @param endPoint  线段结束点* @return 大于0为右侧，小于0为左侧*/public static double isLeftOrRight(Coordinate point, Coordinate startPoint, Coordinate endPoint) {double angleLeft = Angle.angleBetweenOriented(point,startPoint,endPoint);return angleLeft;}/*** 米转换为弧度* 弧度=角度*PI/180* 弧长=半径*弧度* 地球赤道半径=6378137* @param me* @return*/public static double meToDegree(double me){double radius = DistanceUtils.EARTH_MEAN_RADIUS_KM; //地球平均半径BigDecimal bigDecimalCm = new BigDecimal(me);BigDecimal bigDecimalFM = new BigDecimal(1000);double bufferDegree = bigDecimalCm.divide(bigDecimalFM).doubleValue();double kmToDegree = DistanceUtils.dist2Degrees(bufferDegree, radius);return kmToDegree;}/*** 弧度转换为米* 弧度=角度*PI/180* 弧长=半径*弧度* 地球赤道半径=6378137* @param degree* @return*/public static double degreeToMe(double degree){return DistanceUtils.degrees2Dist(degree, DistanceUtils.EARTH_MEAN_RADIUS_KM) * 1000;}