【Turfjs的java版本JTS】前面讲了Turfjs可以实现几何计算，空间计算的功能，如果后端要做这项功能也有类似的类库，JTS

JTS = Java Topology Suite

几何计算：

1. 前端js就用这个 Turfjs的类库。参考网站： 计算两线段相交点 | Turf.js中文网

2. 后端java语言就可以用 JTS这个类库，参考网站：

 JTS参考网站：

1. https://github.com/locationtech/jts

GitHub - locationtech/jts: The JTS Topology Suite is a Java library for creating and manipulating vector geometry.The JTS Topology Suite is a Java library for creating and manipulating vector geometry. - GitHub - locationtech/jts: The JTS Topology Suite is a Java library for creating and manipulating vector geometry.https://github.com/locationtech/jts 2. https://locationtech.github.io/jts/JTS | Documentationhttps://locationtech.github.io/jts/

1. https://github.com/locationtech/jts

2. https://locationtech.github.io/jts/

POM文件：

<dependency><groupId>org.locationtech.jts</groupId><artifactId>jts-core</artifactId><version>1.18.0</version>
</dependency>

实例代码：

可以通过JTS

要使用JTS（Java Topology Suite）库计算

1. 某个点是否在另外一个闭合的空间内
2. 计算某个闭合的空间的中心的的位置

3. 已知两个点的经纬度，计算他们之间的距离

4. 已知某点的经纬度坐标，计算其他点的经纬度坐标

 简单实例如下：

package com.simulate.jts;import org.locationtech.jts.geom.Coordinate;
import org.locationtech.jts.geom.GeometryFactory;
import org.locationtech.jts.geom.Point;
import org.locationtech.jts.geom.Polygon;
import org.locationtech.jts.io.ParseException;
import org.locationtech.jts.io.WKTReader;
import org.locationtech.jts.linearref.LengthIndexedLine;public class JtsExample {public static void main(String[] args) throws ParseException {// 1. 某个点是否在另外一个闭合的空间内// isInside();// 2. 计算某个闭合的空间的中心的的位置// calcCentPoint();//3. 已知两个点的经纬度，计算他们之间的距离// pointDistance();// 4. 已知某点的经纬度坐标，计算其他点的经纬度坐标calcCoordinate();// 5.}// 1. 某个点是否在另外一个闭合的空间内static void isInside() throws ParseException{// 创建 GeometryFactory 对象GeometryFactory geometryFactory = new GeometryFactory();// 创建点对象Coordinate pointCoord = new Coordinate(2.0, 2.0);Point point = geometryFactory.createPoint(pointCoord);// 创建多边形对象WKTReader wktReader = new WKTReader(geometryFactory);Polygon polygon = (Polygon) wktReader.read("POLYGON((0 0, 0 4, 4 4, 4 0, 0 0))");// 判断点是否在多边形内部boolean isInside = polygon.contains(point);// 输出结果System.out.println("Point: " + point.toText());System.out.println("Polygon: " + polygon.toText());System.out.println("Is inside: " + isInside);}// 2. 计算某个闭合的空间的中心的的位置static void calcCentPoint(){int pointCount = 5;Coordinate[] coordinates = new Coordinate[pointCount];// 填充Coordinate数组coordinates[0] = new Coordinate(1.0, 1.0);coordinates[1] = new Coordinate(2.0, 3.0);coordinates[2] = new Coordinate(4.0, 1.0);coordinates[3] = new Coordinate(3.0, 4.0);coordinates[4] = new Coordinate(1.0, 1.0);// 创建Polygon对象GeometryFactory factory = new GeometryFactory();Polygon polygon = factory.createPolygon(coordinates);polygon.getDimension();// 计算中心点坐标Coordinate centerCoordinate = polygon.getCentroid().getCoordinate();double centerX = centerCoordinate.x;double centerY = centerCoordinate.y;// 输出结果System.out.println("Center point: (" + centerX + ", " + centerY + ")");}//3. 已知两个点的经纬度，计算他们之间的距离static void pointDistance(){double lon1 = 115.8575; // 第一个点的经度double lat1 = 28.6829;  // 第一个点的纬度double lon2 = 116.4074; // 第二个点的经度double lat2 = 39.9042;  // 第二个点的纬度// 创建GeometryFactory对象GeometryFactory factory = new GeometryFactory();// 创建Coordinate对象Coordinate coordinate1 = new Coordinate(lon1, lat1);Coordinate coordinate2 = new Coordinate(lon2, lat2);// 创建Point对象Point point1 = factory.createPoint(coordinate1);Point point2 = factory.createPoint(coordinate2);// 计算两点之间的距离double distance = point1.distance(point2);// 输出结果System.out.println("Distance between the two points: " + distance);}/// 4. 已知某点的经纬度坐标，计算其他点的经纬度坐标static void calcCoordinate() {// 假设已知的参考点的坐标double lat1 = 40.7128;   // 参考点的纬度double lon1 = -74.0060;  // 参考点的经度// 假设要计算的距离和方向double distanceInMeters = 1000;  // 距离为 1000 米double bearingInDegrees = 45;    // 方向为 45 度// 创建参考点的坐标对象Coordinate referenceCoord = new Coordinate(lon1, lat1);// 计算目标点的坐标Coordinate targetCoord = calculateCoordinate(referenceCoord, distanceInMeters, bearingInDegrees);// 打印目标点的经纬度System.out.println("目标点的经度：" + targetCoord.x);System.out.println("目标点的纬度：" + targetCoord.y);}// 使用 JTS 计算目标坐标static Coordinate calculateCoordinate(Coordinate referenceCoord, double distance, double bearing) {// 将距离转换为度数double distanceInDegrees = Math.toDegrees(distance / 6371000.0); // 假设地球是一个球体，半径为 6371000 米// 根据参考点和距离创建线段对象// LengthIndexedLine line = new LengthIndexedLine(new Coordinate[] { referenceCoord });GeometryFactory factory = new GeometryFactory();Point referencePoint = factory.createPoint(referenceCoord);LengthIndexedLine line = new LengthIndexedLine(referencePoint);// 在线段上根据方向和距离计算目标点的索引double targetIndex = line.project(referenceCoord) + distanceInDegrees;// 根据目标索引获取目标点的坐标Coordinate targetCoord = line.extractPoint(targetIndex);return targetCoord;}
}