目录
- 求两点之间的球面距离
- 点到线段的最短距离、垂足、垂线
import java.io.FileNotFoundException;
import com.vividsolutions.jts.algorithm.distance.DistanceToPoint;
import com.vividsolutions.jts.algorithm.distance.PointPairDistance;
import com.vividsolutions.jts.geom.*;
import com.vividsolutions.jts.io.ParseException;
import com.vividsolutions.jts.io.WKTReader;
public class Distance {
private static double EARTH_RADIUS = 6378137.0; // WGS84地球椭球体的半径,单位m
//转为弧度
private static double rad(double d) {
return d * Math.PI / 180.0;
}
/**
* 计算两个经纬度之间的球面距离
* @param lat1
* @param lng1
* @param lat2
* @param lng2
* @return
*/
public static double getDistance(double lat1, double lng1, double lat2,double lng2) {
if(lat1<=0D || lng1<=0D || lat2<=0D || lng2<=0D){
throw new RuntimeException("[经纬度必须大于0]");
}
double radLat1 = rad(lat1);
double radLat2 = rad(lat2);
double a = radLat1 - radLat2;
double b = rad(lng1) - rad(lng2);
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;
s = Math.round(s * 10000) / 10000.0;
return s;
}
/**
* 点到线段的最短距离,如果有垂足,锤线最短;如果没有垂线,点到端点的距离最短
* @param point
* @param line
*/
public static void footPoint(Point point, LineString line) {
//定义垂线
PointPairDistance pointPairDistance = new PointPairDistance();
DistanceToPoint.computeDistance(line,point.getCoordinate(),pointPairDistance);
//垂线的长度
double length = pointPairDistance.getDistance();
//垂足,锤线的第一个点
Coordinate footCoord = pointPairDistance.getCoordinate(0);
}
/**
* 主函数
* @param args
* @throws FileNotFoundException
* @throws ParseException
*/
public static void main(String[] args) throws FileNotFoundException, ParseException {
GeometryFactory gf = new GeometryFactory();
Coordinate coord = new Coordinate();
coord.x=115.73334;
coord.y = 39.57573996;
Geometry point = gf.createPoint(coord);
System.out.println(getDistance(31.693982,121.014691,31.716261, 121.021174));
WKTReader reader = new WKTReader(gf);
LineString line = (LineString) reader.read("LINESTRING(118.46075166666667 39.31753333333333,118.461385 39.30982,118.462085 39.30172,118.462955 39.29372)");
Coordinate coord1 = new Coordinate(118.408928,39.281301);
Point point1 = gf.createPoint(coord);
footPoint(point1,line);
}
}