OGR Plugin

DataStore making use of OGR to support a slew of additional data formats.

In order to use the OGR datastore, add the following dependency:

Maven:

<dependency>
   <groupId>org.geotools</groupId>
   <artifactId>gt-ogr-jni</artifactId>
   <version>${geotools.version}</version>
 </dependency>

Your installation of GDAL/OGR needs to be compiled with Java support to use this module.

The OGR DataStore does require the GDAL/OGR native library:

• Add the location to your PATH on Windows, or LD_LIBRARY_PATH on Linux.

• Include this GDAL install location in the java.library.path system property when running your program.

• macOS users are advised to use java.library.path system property (DYLD_LIBRARY_PATH and DYLD_FALLBACK_LIBRARY_PATH environmental variables not recommended).

You can then access the module by creating a DataStoreFactory.

OGRDataStoreFactory factory = new JniOGRDataStoreFactory();

You can list available drivers:

Set<String> drivers = factory.getAvailableDrivers();
for (String driver : drivers) {
    System.out.println(driver);
}

To connect to an OGR layer there are two parameters:

• DriverName = The name of the OGR Driver (http://www.gdal.org/ogr_formats.html).

• DataSourceName = The name of the file or data source connection. This value depends on what driver you are using.

Here is how you would read a shapefile:

Map<String, String> connectionParams = new HashMap<String, String>();
connectionParams.put("DriverName", "ESRI Shapefile");
connectionParams.put("DatasourceName", new File("/Some/where/states.shp").getAbsolutePath());
DataStore store = factory.createDataStore(connectionParams);
SimpleFeatureSource source = store.getFeatureSource("states");

SimpleFeatureIterator it = source.getFeatures().features();
try {
    while (it.hasNext()) {
        SimpleFeature feature = it.next();
        System.out.println(feature.getAttribute("NAME"));
        System.out.println(((Geometry) feature.getDefaultGeometry()).getCentroid());
    }
} finally {
   it.close();
}

Here is how you would count the features in a GeoJSON file. See the GDAL GeoJSON documentation for layer naming details:

File file = new File("states.geojson");
Map<String, String> connectionParams = new HashMap<String, String>();
connectionParams.put("DriverName", "GeoJSON");
connectionParams.put("DatasourceName", file.getAbsolutePath());
DataStore dataStore = DataStoreFinder.getDataStore(connectionParams);
System.out.println(dataStore.getFeatureSource(dataStore.getTypeNames()[0]).getCount(Query.ALL));

Here is how you would write a GeoJSON file:

SimpleFeatureCollection features = getFeatures();
File file = new File("my.geojson");
Map<String, String> connectionParams = new HashMap<String, String>();
connectionParams.put("DriverName", "GeoJSON");
connectionParams.put("DatasourceName", file.getAbsolutePath());
OGRDataStoreFactory factory = new JniOGRDataStoreFactory();
OGRDataStore dataStore = (OGRDataStore) factory.createNewDataStore(connectionParams);
dataStore.createSchema(features, true, null);

And here is now you would write to and then read a SQLite database:

SimpleFeatureCollection features = getFeatures();
File file = new File("features.db");
Map<String, String> connectionParams = new HashMap<String, String>();
connectionParams.put("DriverName", "SQLite");
connectionParams.put("DatasourceName", file.getAbsolutePath());
OGRDataStoreFactory factory = new JniOGRDataStoreFactory();
OGRDataStore dataStore = (OGRDataStore) factory.createNewDataStore(connectionParams);
dataStore.createSchema(features, false, null);

SimpleFeatureSource geoJsonSource = dataStore.getFeatureSource("states");
System.out.println("SQLite Features: " + geoJsonSource.getCount(Query.ALL));
SimpleFeatureIterator it = geoJsonSource.getFeatures().features();
try {
    while (it.hasNext()) {
        SimpleFeature feature = it.next();
        System.out.println(feature.getAttribute("NAME"));
        System.out.println(((Geometry) feature.getDefaultGeometry()).getCentroid());
    }
} finally {
    it.close();
}
dataStore.dispose();