在上一篇文章《GeoTools：Feature&Shapefile之CRUD操作》中，介绍了基于GeoTools的Shapefile文件CRUD基本操作，那么，能否使用GeoTools创建Shapefile文件呢？答案是可以的。以下，我们将深入讨论如何实现。
目录
SimpleFeatureType接口
ShapefileDataStoreFactory类
ShapefileDataStore类
创建Shapefile文件实示例
SimpleFeatureType接口
GeoTools框架内置了SimpleFeatureType接口，用于描述一个Shapefile文件的结构（即：通俗意义上的属性字段信息，既包括属性字段，也包括几何字段）。这个话题在之前已经讨论过。但是问题在于SImpleFeature是一个接口，如何创建其对象呢？
目前我总结下来的有两种方式，
①读取数据源时，通过DataStore数据源实例的getSchema(schemaName)方法获取；
②创建Shapefile文件时，使用GeoTools内置的DataUtilities工具类的createType方法获取。示例代码如下：
final SimpleFeatureType TYPE =
//定义图层的基本结构
DataUtilities.createType(
"Location",
"the_geom:Point:srid=4326,"
+ // <- the geometry attribute: Point type
"name:String,"
+ // <- a String attribute
"number:Integer" // a number attribute
);ShapefileDataStoreFactory类
ShapefileDataStoreFactory类，可用于构建一个Shapefile数据源/存储对象，
通过该类的createNewDataStore()方法，接收一个Map类型的参数，可以创建一个代表Shapefile数据源对象的对象。
以下示例代码使用ShapefileDataStoreFactory类，从一个shp文件，创建一个ShapefileDataStore数据源对象，
String outputfilePath = "C:\\Users\\13241\\Documents\\data\\out.shp";
File file = new File(outputfilePath);
/*
* Get an output file name and create the new shapefile
* ShapefileDataStoreFactory-Builds instances of the shapefile data store
*/
ShapefileDataStoreFactory dataStoreFactory = new ShapefileDataStoreFactory();
Map<String, Serializable> params = new HashMap<>();
params.put("url", file.toURI().toURL());
params.put("create spatial index", Boolean.TRUE);
ShapefileDataStore newDataStore =
(ShapefileDataStore) dataStoreFactory.createNewDataStore(params);ShapefileDataStore类
GeoTools内置了ShapefileDataStore类，用于代表一个Shapefile数据源。该类提供了createNewDataStore()方法，可以基于SImpleFeatureType指定的Shapefile结构，创建一个Shapefile文件。
创建Shapefile文件实示例
以下为创建Shapefile文件，并通过SimpleFeatureCollection将Feature写入到Shapefile文件的完整示例代码。
@Test
public void createShp() throws Exception {
Random random = new Random();//随机数对象生成工具
GeometryFactory geometryFactory = JTSFactoryFinder.getGeometryFactory();//Geometry工厂对象
//创建shp基本结构
SimpleFeatureType featureType = DataUtilities.createType("Polygon",
"the_geom:Polygon:srid=4326," +
"name:String," +
"type:String");
List<AttributeType> types = featureType.getTypes();
types.forEach(System.out::println);
//创建shp文件
String shpFilePath = "C:\\Users\\13241\\Documents\\data\\polygon.shp";
File file = new File(shpFilePath);
if (!file.exists()) file.createNewFile();
ShapefileDataStoreFactory dataStoreFactory = new ShapefileDataStoreFactory();
Map<String, Serializable> params = new HashMap<>();
params.put("url", file.toURI().toURL());
params.put("create spatial index", Boolean.TRUE);
boolean flag = dataStoreFactory.canProcess(params);
if (flag){
ShapefileDataStore newDataStore =
(ShapefileDataStore) dataStoreFactory.createNewDataStore(params);
newDataStore.createSchema(featureType);//创建shp
//获取新创建好的FeatureSource数据源操作
String typeName = newDataStore.getTypeNames()[0];
SimpleFeatureSource featureSource = newDataStore.getFeatureSource(typeName);
// SimpleFeatureType featureType = featureSource.getSchema();//获取shp的表结构
String nameSource = "sdajlskdadasl;d,a;ldal;sdaldam,sdadsad";
String[] typeArray = new String[]{"group_one","group_two","group_three","group_four"};
//构造FeatureCollection数据源
List<SimpleFeature> features = new ArrayList<>();
SimpleFeatureBuilder featureBuilder = new SimpleFeatureBuilder(featureType);//Feature要素构造器
for (int i = 0; i < 15; i++) {
double longitude = 120.0 + Math.random()*10,
latitude = 30.0 + Math.random()*10;
Coordinate[] coordinates = new Coordinate[]{
new Coordinate(longitude - 1,latitude-1),
new Coordinate(longitude - 1,latitude+1),
new Coordinate(longitude + 1,latitude+1),
new Coordinate(longitude + 1,latitude-1),
new Coordinate(longitude - 1,latitude-1)
// new Coordinate(119.0,32.0),
// new Coordinate(119.0,32.5),
// new Coordinate(120.0,32.5),
// new Coordinate(120.0,32.0),
// new Coordinate(119.0,32.0)
};
Polygon polygon = geometryFactory.createPolygon(coordinates);
featureBuilder.add(polygon);
featureBuilder.add(nameSource.substring(0,3+random.nextInt(nameSource.length()-5)));
featureBuilder.add(typeArray[random.nextInt(typeArray.length)]);
SimpleFeature simpleFeature = featureBuilder.buildFeature(null);
features.add(simpleFeature);
}
//根据List<SimpleFeature>构造SimpleFeatureCollection,并将其添加到Shapefile文件中
if (featureSource instanceof SimpleFeatureStore) {
SimpleFeatureStore featureStore = (SimpleFeatureStore) featureSource;
SimpleFeatureCollection collection = new ListFeatureCollection(featureType, features);
Transaction transaction = new DefaultTransaction("create");
featureStore.setTransaction(transaction);
try {
featureStore.addFeatures(collection);
transaction.commit();
} catch (Exception problem) {
problem.printStackTrace();
transaction.rollback();
} finally {
transaction.close();
}
System.exit(0); // success!
}
}else{
throw new Exception("操作不被支持!");
}
}将创建好的shapefile文件放入QGIS中进行加载，显示效果如下，
