请提供gt-mbtiles实现mbtiles写入操作的代码

以下是使用 GeoTools 中的 MBTilesDataStore 类实现 MBTiles 文件写入操作的示例代码：

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.util.HashMap;
import java.util.Map;
import org.geotools.data.DataStore;
import org.geotools.data.DataStoreFinder;
import org.geotools.data.DefaultTransaction;
import org.geotools.data.Transaction;
import org.geotools.data.mbtiles.MBTilesDataStoreFactory;
import org.geotools.data.simple.SimpleFeatureSource;
import org.geotools.feature.FeatureIterator;
import org.geotools.geometry.jts.JTSFactoryFinder;
import org.geotools.referencing.CRS;
import org.locationtech.jts.geom.Coordinate;
import org.locationtech.jts.geom.GeometryFactory;
import org.opengis.feature.simple.SimpleFeature;
import org.opengis.feature.simple.SimpleFeatureType;

public class MBTilesWriter {

    public static void main(String[] args) throws Exception {
        // 设置 MBTiles 文件路径和名称
        File file = new File("path/to/mbtiles_file.mbtiles");

        // 创建 MBTilesDataStore 参数
        Map<String, Object> params = new HashMap<>();
        params.put(MBTilesDataStoreFactory.PARAMETER_FILE, file);

        // 创建 MBTilesDataStore 实例
        DataStore store = DataStoreFinder.getDataStore(params);

        // 创建图层数据表结构
        SimpleFeatureType type = DataUtilities.createType("Tile", "the_geom:Point:srid=3857,name:String,level:Integer,row:Integer,column:Integer");

        // 开启事务并获取 FeatureWriter
        Transaction transaction = new DefaultTransaction();
        SimpleFeatureSource source = store.getFeatureSource("Tile");
        FeatureWriter<SimpleFeatureType, SimpleFeature> writer = source.getFeatureWriter(type, transaction);

        // 读取瓦片数据并写入 MBTiles
        File tilesDir = new File("path/to/tiles_directory");
        File[] zoomDirs = tilesDir.listFiles();
        for (File zoomDir : zoomDirs) {
            int zoomLevel = Integer.parseInt(zoomDir.getName());
            File[] rowDirs = zoomDir.listFiles();
            for (File rowDir : rowDirs) {
                int row = Integer.parseInt(rowDir.getName());
                File[] tileFiles = rowDir.listFiles();
                for (File tileFile : tileFiles) {
                    int column = Integer.parseInt(tileFile.getName().split("\\.")[0]);
                    byte[] tileData = Files.readAllBytes(tileFile.toPath());

                    // 计算瓦片左上角经纬度坐标
                    double[] bbox = TileBoundingBox.getBoundingBox(zoomLevel, row, column);
                    Coordinate coordinate = new Coordinate(bbox[0], bbox[3]);

                    // 创建 SimpleFeature 并写入 MBTiles
                    SimpleFeature feature = writer.next();
                    feature.setAttribute("the_geom", geometryFactory.createPoint(coordinate));
                    feature.setAttribute("name", zoomLevel + "/" + row + "/" + column);
                    feature.setAttribute("level", zoomLevel);
                    feature.setAttribute("row", row);
                    feature.setAttribute("column", column);
                    feature.setDefaultGeometry(geometryFactory.createPoint(coordinate));
                    feature.getUserData().put(SimpleFeature.DEFAULT_GEOMETRY, "the_geom");
                    feature.getUserData().put("minZoom", zoomLevel);
                    feature.getUserData().put("maxZoom", zoomLevel);
                    feature.getUserData().put("format", "image/png");
                    feature.getUserData().put("data", tileData);
                    writer.write();

                    // 提交事务并关闭 FeatureWriter
                    transaction.commit();
                    writer.close();
                }
            }
        }

        // 关闭事务和数据源
        transaction.close();
        store.dispose();
    }
}

以上示例代码演示了如何使用 GeoTools 的 MBTilesDataStore 类读取瓦片数据并写入 MBTiles 文件。在实际应用中，您需要根据实际情况设置 MBTiles 文件的路径、瓦片数据的路径、瓦片数据格式等参数，并确保瓦片数据和 MBTiles 文件的坐标系一致。