GeoTools：将自定义多边形插入现有的 .shapefile答案

【问题标题】：GeoTools: insert custom Polygons into existiong .shp fileGeoTools：将自定义多边形插入现有的 .shapefile
【发布时间】：2020-11-25 09:42:19
【问题描述】：

我是 Geotools 的新手。现在我想在奥地利的 Shapefile 中插入一个自定义区域（多边形）。我的代码：

 public static void main(String[] args) throws IOException {
        File file = new File("src/main/java/org/geotools/austria.shp");
        Map<String, Object> map = new HashMap<>();
        map.put("url", file.toURI().toURL());

        DataStore dataStore = DataStoreFinder.getDataStore(map);
        String typeName = dataStore.getTypeNames()[0];
        FeatureSource<SimpleFeatureType, SimpleFeature> source =
                dataStore.getFeatureSource(typeName);

        MapContent showmap = new MapContent();
        showmap.setTitle("Austria");

        Style style = SLD.createSimpleStyle(source.getSchema());
        Layer layer = new FeatureLayer(source, style);
        showmap.addLayer(layer);

        // display the map
        JMapFrame.showMap(showmap);
    }

我目前的结果：

这张图片显示了我当前的输出。我画了一个红色的六边形来展示我将来想要的东西。如何将此多边形插入并显示到 Shapefile 中？

【问题讨论】：

标签： java shapefile geo geotools

【解决方案1】：

首先，您需要创建一个新的 Shapefile（您可以覆盖旧的，但这样很容易丢失数据）。

SimpleFeatureType TYPE = dataStore.getSchema(typeName);
File newFile = new File("output.shp");
ShapefileDataStoreFactory dataStoreFactory = new ShapefileDataStoreFactory();

Map<String, Serializable> params = new HashMap<String, Serializable>();
params.put("url", URLs.fileToURL(newFile));
params.put("create spatial index", Boolean.TRUE);

ShapefileDataStore newDataStore = (ShapefileDataStore) dataStoreFactory.createNewDataStore(params);
newDataStore.createSchema(TYPE);

然后您需要将现有多边形复制到新文件中（我假设它们位于名为 collection 的 SimpleFeatureCollection 中），然后是新功能：

Transaction transaction = new DefaultTransaction("create");

String typeName = newDataStore.getTypeNames()[0];
SimpleFeatureSource featureSource = newDataStore.getFeatureSource(typeName);

if (featureSource instanceof SimpleFeatureStore) {
    SimpleFeatureStore featureStore = (SimpleFeatureStore) featureSource;

    featureStore.setTransaction(transaction);
    try {
        featureStore.addFeatures(collection);
        
        // Now add the hexagon
        featureStore.addFeatures(DataUtilities.collection(hexagon));
        transaction.commit();
     } catch (Exception problem) {
        problem.printStackTrace();
        transaction.rollback();
        System.exit(-1);
     } finally {
        transaction.close();
     }
} else {
    System.out.println(typeName + " does not support read/write access");
    System.exit(1);
}

【讨论】：