org.geotools.data

Interface DataStore

All Superinterfaces:

DataAccess<SimpleFeatureType,SimpleFeature>

All Known Subinterfaces:

FileDataStore

All Known Implementing Classes:

ArcSDEDataStore, ContentDataStore, DataStoreWrapper, DecoratingDataStore, DirectoryDataStore, JDBCDataStore, MemoryDataStore, MongoDataStore, OracleDatastoreWrapper, PostgisDatastoreWrapper, PreGeneralizedDataStore, PropertyDataStore, ShapefileDataStore, SingleFeatureSourceDataStore, WFSDataStore

public interface DataStore
extends DataAccess<SimpleFeatureType,SimpleFeature>

This represents a physical source of feature data, such as a shapefiles or database, where the features will be instances of SimpleFeature. It is derived from the DataAccess interface (which works at the more general Feature level.

Author:

Jody Garnett, Refractions Research

See Also:

DataAccess, Feature, SimpleFeature

Method Summary

Modifier and Type	Method and Description
FeatureReader<SimpleFeatureType,SimpleFeature>	getFeatureReader(Query query, Transaction transaction) Gets a FeatureReader for features selected by the given Query.
SimpleFeatureSource	getFeatureSource(Name typeName) Gets a SimpleFeatureSource for features of the type specified by a qualified name (namespace plus type name).
SimpleFeatureSource	getFeatureSource(String typeName) Gets a SimpleFeatureSource for features of the specified type.
FeatureWriter<SimpleFeatureType,SimpleFeature>	getFeatureWriter(String typeName, Filter filter, Transaction transaction) Gets a FeatureWriter to modify features in this DataStore.
FeatureWriter<SimpleFeatureType,SimpleFeature>	getFeatureWriter(String typeName, Transaction transaction) Gets a FeatureWriter to modify features in this DataStore.
FeatureWriter<SimpleFeatureType,SimpleFeature>	getFeatureWriterAppend(String typeName, Transaction transaction) Gets a FeatureWriter that can add new features to the DataStore.
LockingManager	getLockingManager() Retrieve a per featureID based locking service from this DataStore.
SimpleFeatureType	getSchema(String typeName) Gets the type information (schema) for the specified feature type.
String[]	getTypeNames() Gets the names of feature types available in this DataStore.
void	removeSchema(String typeName) Used to permanently remove a schema from the underlying storage This functionality is similar to an "drop table" statement in SQL.
void	updateSchema(String typeName, SimpleFeatureType featureType) Applies a new schema to the given feature type.

Methods inherited from interface DataAccess

createSchema, dispose, getInfo, getNames, getSchema, removeSchema, updateSchema

Method Detail

updateSchema

void updateSchema(String typeName,
                  SimpleFeatureType featureType)
           throws IOException

Applies a new schema to the given feature type. This can be used to add or remove properties. The resulting update will be persistent.

Parameters:

typeName - name of the feature type to update

featureType - the new schema to apply

Throws:

IOException - on error

removeSchema

void removeSchema(String typeName)
           throws IOException

Used to permanently remove a schema from the underlying storage

This functionality is similar to an "drop table" statement in SQL. Implementation is optional; it may not be supported by all servers or files.

Parameters:

typeName -

Throws:

IOException - if the operation failed

UnsupportedOperation - if functionality is not available

getTypeNames

String[] getTypeNames()
               throws IOException

Gets the names of feature types available in this DataStore. Please note that this is not guaranteed to return a list of unique names since the same unqualified name may be present in separate namespaces within the DataStore.

Returns:

names of feature types available in this DataStore

Throws:

IOException - if data access errors occur

getSchema

SimpleFeatureType getSchema(String typeName)
                     throws IOException

Gets the type information (schema) for the specified feature type.

Parameters:

typeName - the feature type name

Returns:

the requested feature type

Throws:

IOException - if typeName is not available

getFeatureSource

SimpleFeatureSource getFeatureSource(String typeName)
                              throws IOException

Gets a SimpleFeatureSource for features of the specified type. SimpleFeatureSource provides a high-level API for feature operations.

The resulting SimpleFeatureSource may implment more functionality as in this example:

 SimpleFeatureSource fsource = dataStore.getFeatureSource("roads");
 if (fsource instanceof SimpleFeatureStore) {
     // we have write access to the feature data
     SimpleFeatureStore fstore = (SimpleFeatureStore) fs;
 }
 else {
     // System.out.println("We do not have write access to roads");
 }
 

Parameters:

typeName - the feature type

Returns:

a SimpleFeatureSource (or possibly a subclass) providing operations for features of the specified type

Throws:

IOException - if data access errors occur

See Also:

SimpleFeatureSource, SimpleFeatureStore

getFeatureSource

SimpleFeatureSource getFeatureSource(Name typeName)
                              throws IOException

Gets a SimpleFeatureSource for features of the type specified by a qualified name (namespace plus type name).

Specified by:

getFeatureSource in interface DataAccess<SimpleFeatureType,SimpleFeature>

Parameters:

typeName - the qualified name of the feature type

Returns:

a SimpleFeatureSource (or possibly a subclass) providing operations for features of the specified type

Throws:

IOException - if data access errors occur

See Also:

getFeatureSource(String), SimpleFeatureSource, SimpleFeatureStore

getFeatureReader

FeatureReader<SimpleFeatureType,SimpleFeature> getFeatureReader(Query query,
                                                                Transaction transaction)
                                                         throws IOException

Gets a FeatureReader for features selected by the given Query. FeatureReader provies an iterator-style API to feature data.

The Query provides the schema for the form of the returned features as well as a Filter to constrain the features available via the reader.

The Transaction can be used to externalize the state of the DataStore. Examples of this include a JDBCDataStore sharing a connection for use across several FeatureReader requests; and a ShapefileDataStore redirecting requests to an alternate file during the course of a Transaction.

Parameters:

query - a query providing the schema and constraints for features that the reader will return

transaction - a transaction that this reader will operate against

Returns:

an instance of FeatureReader

Throws:

IOException - if data access errors occur

getFeatureWriter

FeatureWriter<SimpleFeatureType,SimpleFeature> getFeatureWriter(String typeName,
                                                                Filter filter,
                                                                Transaction transaction)
                                                         throws IOException

Gets a FeatureWriter to modify features in this DataStore. FeatureWriter provides an iterator style API to features.

The returned writer does not allow features to be added.

Parameters:

typeName - the type name for features that will be accessible

filter - defines additional constraints on the features that will be accessible

transaction - the transation that the returned writer operates against

Returns:

an instance of FeatureWriter

Throws:

IOException - if data access errors occur

See Also:

getFeatureWriterAppend(String, Transaction)

getFeatureWriter

FeatureWriter<SimpleFeatureType,SimpleFeature> getFeatureWriter(String typeName,
                                                                Transaction transaction)
                                                         throws IOException

Gets a FeatureWriter to modify features in this DataStore. FeatureWriter provides an iterator style API to features.

The returned writer does not allow features to be added.

Parameters:

typeName - the type name for features that will be accessible

transaction - the transation that the returned writer operates against

Returns:

an instance of FeatureWriter

Throws:

IOException - if data access errors occur

See Also:

getFeatureWriterAppend(String, Transaction)

getFeatureWriterAppend

FeatureWriter<SimpleFeatureType,SimpleFeature> getFeatureWriterAppend(String typeName,
                                                                      Transaction transaction)
                                                               throws IOException

Gets a FeatureWriter that can add new features to the DataStore.

The FeatureWriter will return false when its hasNext() method is called, but next() can be used to acquire new features.

Parameters:

typeName - name of the feature type for which features will be added

transaction - the transaction to operate against

Returns:

an instance of FeatureWriter that can only be used to append new features

Throws:

IOException - if data access errors occur

getLockingManager

LockingManager getLockingManager()

Retrieve a per featureID based locking service from this DataStore.

Returns:

an instance of LockingManager; or null if locking is handled by the DataStore in a different fashion