地图(高德)判断某一点位是否位于某一城市/地区/行政区划内

这里以高德地图示例，其他地图思路是类似的

调用API（可以申请api选择web服务获取key）

https://restapi.amap.com/v3/config/district?key=yourAppKey&keywords=330500&extensions=all

传入需要的行政区域代码，得到如下数据，得到polyline是该地区的经纬度范围

用类似的思路也可以自定义范围来判断

Polygon 和 MultiPolygon 是用来表示地理空间数据的重要几何类型，选择需要的使用

import org.locationtech.jts.algorithm.PointLocator;
import org.locationtech.jts.geom.*;

/**
 * 高德地图判断点位是否在区域内
 */
public class AMapUtils {
    // 湖州市 https://restapi.amap.com/v3/config/district?key=yourAppKey&keywords=330500&extensions=all
    public static final String hz_330500_polyline = "119.35233,30.421692;119.352496,30.422054;119.352971,30.424851;119.35268,30.425771;119.352023,30.427157;119.3508,30.429113;119.349119,30.432065;119.348813,30.433614;119.349692,30.438824;119.348722,30.440093;119.348386,30.440561;119.348133,30.440734;119.345771,30.442303;119.343669......注意经纬度要首尾相连";

    public static boolean pointIsInHuZhou(double longitude, double latitude) {
        //因为边界信息里面包含;和|分隔符，都需要切割
        String[] hzpoints = hz_330500_polyline.split(";|\\|");
        // 创建GeometryFactory
        GeometryFactory geometryFactory = new GeometryFactory();
        // 创建点坐标
        Coordinate pointCoordinate = new Coordinate(longitude, latitude);
        Coordinate[] coordinates = new Coordinate[hzpoints.length + 1];
        //起始经纬度
        double longitudeF = Double.parseDouble(hzpoints[0].split(",")[0]); // 经度
        double latitudeF = Double.parseDouble(hzpoints[0].split(",")[1]); // 纬度
        coordinates[0] = new Coordinate(longitudeF, latitudeF);
        // 遍历多边形Map，查找包含点的多边形
        for (int i = 1; i < hzpoints.length; i++) {
            double longitude1 = Double.parseDouble(hzpoints[i].split(",")[0]); // 经度
            double latitude1 = Double.parseDouble(hzpoints[i].split(",")[1]); // 纬度
            coordinates[i] = new Coordinate(longitude1, latitude1);
        }
        // 一定要首尾相连，不然就会报错
        coordinates[hzpoints.length] = new Coordinate(longitudeF, latitudeF);
        return multiPolygonProcess(geometryFactory, coordinates, pointCoordinate);
    }

    /**
     * 通过MultiPolygon判断
     *
     * @param geometryFactory
     * @param coordinates
     * @param pointCoordinate
     * @return
     */
    private static boolean multiPolygonProcess(GeometryFactory geometryFactory, Coordinate[] coordinates, Coordinate pointCoordinate) {
        try {
            // 创建MultiPolygon对象
            MultiPolygon multiPolygon = geometryFactory
                    .createMultiPolygon(new Polygon[]{new GeometryFactory().createPolygon(coordinates)});
            // 使用PointLocator检查点是否在多边形内
            PointLocator pointLocator = new PointLocator();
            int location = pointLocator.locate(pointCoordinate, multiPolygon);
            return location != Location.EXTERIOR;
        } catch (Exception e) {
            System.out.println("异常原因:" + e);
        }
        return false;
    }

    /**
     * 通过Polygon判断
     *
     * @param geometryFactory
     * @param coordinates
     * @param pointCoordinate
     * @return
     */
    private static boolean polygonProcess(GeometryFactory geometryFactory, Coordinate[] coordinates, Coordinate pointCoordinate) {
        try {
            LinearRing ring = geometryFactory.createLinearRing(coordinates);
            Polygon polygon = geometryFactory.createPolygon(ring, null);
            Point point = geometryFactory.createPoint(pointCoordinate); // 待判断的点
            return point.within(polygon);
        } catch (Exception e) {
            System.out.println("异常原因:" + e);
        }
        return false;
    }
}