java实现离线正反向地理编码代码

Java实现离线正反向地理编码需要用到第三方库，比如Geocoder、Geotools、OSM Nominatim等。以下是一个使用Geotools实现离线正向地理编码的示例代码：

import org.geotools.data.shapefile.ShapefileDataStore;
import org.geotools.data.simple.SimpleFeatureIterator;
import org.geotools.feature.simple.SimpleFeatureImpl;
import org.geotools.geometry.jts.JTSFactoryFinder;
import org.opengis.feature.simple.SimpleFeature;
import org.opengis.feature.simple.SimpleFeatureType;
import org.opengis.geometry.coordinate.Position;
import org.opengis.referencing.crs.CoordinateReferenceSystem;
import org.opengis.referencing.operation.MathTransform;
import org.opengis.referencing.operation.TransformException;

import java.io.File;
import java.io.IOException;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;

import org.locationtech.jts.geom.Coordinate;
import org.locationtech.jts.geom.Geometry;
import org.locationtech.jts.geom.GeometryFactory;
import org.locationtech.jts.geom.Point;
import org.locationtech.jts.io.ParseException;
import org.locationtech.jts.io.WKTReader;

public class GeoCoder {
    private ShapefileDataStore dataStore;
    private SimpleFeatureType featureType;
    private MathTransform transform;
    private Map<Long, String> id2Name;

    public GeoCoder(File shapefile) throws IOException {
        dataStore = new ShapefileDataStore(shapefile.toURL());
        featureType = dataStore.getSchema();
        CoordinateReferenceSystem sourceCRS = featureType.getCoordinateReferenceSystem();
        CoordinateReferenceSystem targetCRS = org.geotools.referencing.crs.DefaultGeographicCRS.WGS84;
        transform = org.geotools.referencing.CRS.findMathTransform(sourceCRS, targetCRS, true);
        id2Name = new HashMap<>();
        SimpleFeatureIterator iterator = dataStore.getFeatureSource().getFeatures().features();
        while (iterator.hasNext()) {
            SimpleFeature feature = iterator.next();
            long id = (Long) feature.getAttribute("ID");
            String name = (String) feature.getAttribute("NAME");
            id2Name.put(id, name);
        }
        iterator.close();
    }

    public String getAddress(double lat, double lon) throws IOException, TransformException {
        GeometryFactory geometryFactory = JTSFactoryFinder.getGeometryFactory();
        Point point = geometryFactory.createPoint(new Coordinate(lon, lat));
        Geometry targetGeometry = null;
        try {
            targetGeometry = JTS.transform(point, transform);
        } catch (TransformException e) {
            e.printStackTrace();
        }
        if (targetGeometry != null) {
            String wktPoint = targetGeometry.toText();
            String[] coords = wktPoint.replace("POINT (", "").replace(")", "").split(" ");
            double x = Double.parseDouble(coords[0]);
            double y = Double.parseDouble(coords[1]);
            Geometry searchGeometry = geometryFactory.createPoint(new Coordinate(x, y));
            try {
                SimpleFeatureIterator iterator = dataStore.getFeatureSource().getFeatures().features();
                while (iterator.hasNext()) {
                    SimpleFeature feature = iterator.next();
                    Geometry geometry = (Geometry) feature.getDefaultGeometry();
                    if (searchGeometry.intersects(geometry)) {
                        long id = (Long) feature.getAttribute("ID");
                        String name = id2Name.get(id);
                        return name;
                    }
                }
                iterator.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return null;
    }
}

示例代码使用了一个Shapefile作为地理编码数据源，通过读取Shapefile的属性表生成一个id到名称的映射表，并且可以通过给定的经纬度坐标返回对应的名称。