Geotools创建Shapefile的SimpleFeatureWriter时遇类型转换异常

问题描述 #

我尝试编写Shapefile，代码如下：

File shapefile = new File(....);
Map<String, Serializable> map = new HashMap();
map.put("url", shapefile.toURI().toURL());
SimpleFeatureTypeBuilder builder = new SimpleFeatureTypeBuilder();
builder.setName("MultiPolygonFeatureType");
CoordinateReferenceSystem crs = DefaultGeographicCRS.WGS84
builder.setCRS(crs);
builder.add("location", MultiPolygon.class);
builder.add("name", String.class);
SimpleFeatureType featureType = builder.buildFeatureType();
ShapefileDataStoreFactory factory = new ShapefileDataStoreFactory();
ShapefileDataStore dataStore = (ShapefileDataStore) factory.createNewDataStore(map);
dataStore.createSchema(featureType);
SimpleFeatureWriter writer = (SimpleFeatureWriter) dataStore.getFeatureWriterAppend(dataStore.getTypeNames()[0], new DefaultTransaction());

运行时报错：

java.lang.ClassCastException: class org.geotools.data.InProcessLockingManager$1 cannot be cast to class org.geotools.data.simple.SimpleFeatureWriter(org.geotools.data.InProcessLockingManager$1 and org.geotools.data.simple.SimpleFeatureWriter are in unnamed module of loader 'app')

请问我遗漏了什么内容？

解决方法 #

1. 修正类型转换错误
   getFeatureWriterAppend方法返回的是FeatureWriter<SimpleFeatureType, SimpleFeature>类型，不能直接强转为SimpleFeatureWriter，需使用正确的类型声明：

FeatureWriter<SimpleFeatureType, SimpleFeature> writer = dataStore.getFeatureWriterAppend(dataStore.getTypeNames()[0], new DefaultTransaction());

2. 修复语法错误
   代码中CoordinateReferenceSystem crs = DefaultGeographicCRS.WGS84一行末尾缺少分号，补充后：

CoordinateReferenceSystem crs = DefaultGeographicCRS.WGS84;

内容的提问来源于stack exchange，提问作者Mandroid