springboot GeoPackage

GeoPackage是一种开放的地理空间数据格式，它结合了矢量数据、栅格数据和属性数据，可以在移动设备和桌面平台上进行存储和共享。GeoPackage是一种基于SQLite的文件格式，它使用标准的SQL查询语言来操作和查询地理空间数据。

在Spring Boot中使用GeoPackage可以通过以下步骤实现：

1. 添加依赖：在`pom.xml`文件中添加以下依赖：

<dependency>
    <groupId>org.geotools</groupId>
    <artifactId>gt-geopkg</artifactId>
    <version>24.0</version>
</dependency>

2. 创建GeoPackage文件：使用GeoTools库创建一个新的GeoPackage文件，并定义表结构和数据。

import org.geotools.data.DataStore;
import org.geotools.data.DataStoreFinder;
import org.geotools.data.simple.SimpleFeatureSource;
import org.geotools.data.simple.SimpleFeatureStore;
import org.geotools.feature.simple.SimpleFeatureBuilder;
import org.geotools.feature.simple.SimpleFeatureTypeBuilder;
import org.opengis.feature.simple.SimpleFeature;
import org.opengis.feature.simple.SimpleFeatureType;

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

public class GeoPackageExample {

    public static void main(String[] args) throws IOException {
        // 创建GeoPackage文件
        File file = new File("path/to/geopackage.gpkg");
        Map<String, Object> params = new HashMap<>();
        params.put("dbtype", "geopkg");
        params.put("database", file);

        DataStore dataStore = DataStoreFinder.getDataStore(params);

        // 定义表结构
        SimpleFeatureTypeBuilder typeBuilder = new SimpleFeatureTypeBuilder();
        typeBuilder.setName("my_table");
        typeBuilder.add("geometry", Point.class);
        typeBuilder.add("name", String.class);
        SimpleFeatureType featureType = typeBuilder.buildFeatureType();

        // 创建要素
        SimpleFeatureBuilder featureBuilder = new SimpleFeatureBuilder(featureType);
        featureBuilder.add(geometry);
        featureBuilder.add("example");
        SimpleFeature feature = featureBuilder.buildFeature(null);

        // 写入数据
        SimpleFeatureStore featureStore = (SimpleFeatureStore) dataStore.getFeatureSource("my_table");
        featureStore.addFeatures(DataUtilities.collection(feature));
    }
}

3. 读取GeoPackage数据：使用GeoTools库读取GeoPackage文件中的数据。

import org.geotools.data.DataStore;
import org.geotools.data.DataStoreFinder;
import org.geotools.data.simple.SimpleFeatureSource;
import org.opengis.feature.simple.SimpleFeature;
import org.opengis.feature.simple.SimpleFeatureType;

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

public class GeoPackageExample {

    public static void main(String[] args) throws IOException {
        // 读取GeoPackage文件
        File file = new File("path/to/geopackage.gpkg");
        Map<String, Object> params = new HashMap<>();
        params.put("dbtype", "geopkg");
        params.put("database", file);

        DataStore dataStore = DataStoreFinder.getDataStore(params);

        // 获取要素源
        SimpleFeatureSource featureSource = dataStore.getFeatureSource("my_table");

        // 遍历要素
        try (SimpleFeatureIterator iterator = featureSource.getFeatures().features()) {
            while (iterator.hasNext()) {
                SimpleFeature feature = iterator.next();
                // 处理要素数据
                Geometry geometry = (Geometry) feature.getDefaultGeometry();
                String name = (String) feature.getAttribute("name");
                System.out.println("Geometry: " + geometry);
                System.out.println("Name: " + name);
            }
        }
    }
}

这样就可以在Spring Boot中使用GeoPackage进行地理空间数据的存储和查询了。