通过GraphHopper实现地理编码代码

以下是使用GraphHopper实现地理编码的代码示例：

首先需要导入GraphHopper依赖：

<dependency>
    <groupId>com.graphhopper</groupId>
    <artifactId>graphhopper-core</artifactId>
    <version>1.0</version>
</dependency>

然后可以使用以下代码进行地理编码：

import com.graphhopper.GHResponse;
import com.graphhopper.GraphHopper;
import com.graphhopper.routing.util.AllEdgesIterator;
import com.graphhopper.routing.util.EdgeFilter;
import com.graphhopper.routing.util.FlagEncoder;
import com.graphhopper.routing.util.LevelEdgeFilter;
import com.graphhopper.routing.util.WeightedEdgeIterator;
import com.graphhopper.storage.GraphHopperStorage;
import com.graphhopper.storage.index.LocationIndexTree;
import com.graphhopper.util.EdgeIterator;
import com.graphhopper.util.EdgeIteratorState;
import com.graphhopper.util.PointList;
import com.graphhopper.util.shapes.GHPoint;

public class GeoCoder {
    private final GraphHopper hopper;

    public GeoCoder() {
        // 初始化GraphHopper
        hopper = new GraphHopper();
        hopper.setDataReaderFile("path/to/your/graphhopper-data.osm.pbf");
        hopper.setGraphHopperLocation("path/to/your/graphhopper-location");
        hopper.setEncodingManager(new EncodingManager("car"));
        hopper.importOrLoad();
    }

    public GHPoint geocode(String address) {
        // 使用LocationIndexTree进行地理编码
        LocationIndexTree index = (LocationIndexTree) hopper.getLocationIndex();
        GHResponse ghResponse = new GHResponse();
        index.findClosest(address, ghResponse);

        if (ghResponse.hasErrors()) {
            throw new IllegalStateException("Cannot find point for address: " + address);
        }

        return ghResponse.getClosestPoint();
    }

    public String reverseGeocode(GHPoint point) {
        // 使用GraphHopperStorage进行逆向地理编码
        GraphHopperStorage graph = hopper.getGraphHopperStorage();
        FlagEncoder encoder = hopper.getEncodingManager().getEncoder("car");
        EdgeFilter filter = new LevelEdgeFilter(graph, encoder);
        Weighting weighting = new FastestWeighting(encoder);
        EdgeExplorer explorer = graph.createEdgeExplorer(filter);
        EdgeIterator iter = explorer.setBaseNode(GraphUtil.getClosestNode(graph, point.getLat(), point.getLon(), filter));

        while (iter.next()) {
            if (iter.isForward(encoder)) {
                PointList pl = iter.fetchWayGeometry(2);
                double distance = iter.getDistance();
                double time = weighting.calcMillis(iter, false, EdgeIterator.NO_EDGE);

                return String.format("Distance: %.1f m, Time: %.1f s, Location: (%f,%f)", distance, time / 1000.0, pl.getLat(0), pl.getLon(0));
            }
        }

        throw new IllegalStateException("Cannot reverse geocode point: " + point);
    }
}

上述代码包含了两个方法：`geocode`用于将地址编码为地理坐标，`reverseGeocode`用于将地理坐标逆向编码为地址。请注意，这里使用了`LocationIndexTree`和`GraphHopperStorage`两个类来实现地理编码和逆向地理编码。