java根据生成shp文件

Java可以利用开源库GeoTools生成shp文件。GeoTools是一个开发平台，用于处理空间数据。它提供了丰富的API来读取、写入和操作各种GIS数据格式，包括矢量数据格式（如Shapefile、GML、KML等）和栅格数据格式（如GeoTIFF、NetCDF等）。

要使用GeoTools生成shp文件，您需要在Java项目中添加GeoTools的库文件。接着，您需要创建一个FeatureCollection对象，该对象将包含要在shp文件中写入的所有矢量要素（例如点、线、多边形等）。要创建FeatureCollection对象，您可以使用DefaultFeatureCollection类。

然后，您需要使用FeatureTypeBuilder类创建FeatureType对象。 FeatureType定义要素的结构，包括属性名称、数据类型和坐标参考系等。最后，您可以使用FeatureBuilder类将要素添加到FeatureCollection对象中，并调用FeatureWriter类将FeatureCollection写入shp文件。

例如，以下是使用GeoTools在Java中创建一个包含两个点的shp文件的示例：

CoordinateReferenceSystem crs = CRS.decode("EPSG:4326");

SimpleFeatureTypeBuilder builder = new SimpleFeatureTypeBuilder();
builder.setName("Location");
builder.setCRS(crs);
builder.add("the_geom", Point.class);
builder.add("name", String.class);

SimpleFeatureType featureType = builder.buildFeatureType();

DefaultFeatureCollection featureCollection = new DefaultFeatureCollection("locations", featureType);

GeometryFactory geometryFactory = JTSFactoryFinder.getGeometryFactory();

SimpleFeatureBuilder featureBuilder = new SimpleFeatureBuilder(featureType);

Point point1 = geometryFactory.createPoint(new Coordinate(2.0, 1.0));
featureBuilder.set("the_geom", point1);
featureBuilder.set("name", "Point 1");
SimpleFeature feature1 = featureBuilder.buildFeature(null);

Point point2 = geometryFactory.createPoint(new Coordinate(4.0, 3.0));
featureBuilder.set("the_geom", point2);
featureBuilder.set("name", "Point 2");
SimpleFeature feature2 = featureBuilder.buildFeature(null);

featureCollection.add(feature1);
featureCollection.add(feature2);

File newFile = new File("locations.shp");

ShapefileDataStoreFactory dataStoreFactory = new ShapefileDataStoreFactory();

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

ShapefileDataStore dataStore = (ShapefileDataStore) dataStoreFactory.createNewDataStore(params);

dataStore.createSchema(featureType);

String typeName = dataStore.getTypeNames()[0];

FeatureWriter<SimpleFeatureType, SimpleFeature> featureWriter = dataStore.getFeatureWriter(typeName, Transaction.AUTO_COMMIT);

try {
    while (featureCollection.features().hasNext()) {
        SimpleFeature feature = featureCollection.features().next();
        SimpleFeature copy = featureWriter.next();
        copy.setAttributes(feature.getAttributes());
        featureWriter.write();
    }
} finally {
    featureWriter.close();
    dataStore.dispose();
}

在此示例中，我们创建了包含两个点的FeatureCollection对象。它们分别被命名为“Point 1”和“Point 2”。我们还使用CoordinateReferenceSystem对象定义了编码为“EPSG:4326”的坐标参考系。最后，我们使用ShapefileDataStore类将FeatureCollection对象写入名为“locations”的shp文件中。

总之，使用GeoTools可以方便地在Java中生成shp文件。它为开发人员提供了强大且易于使用的API，可以生成各种GIS数据格式。