Package org.geotools.jdbc

Class JDBCFeatureSource

Object

ContentFeatureSource

JDBCFeatureSource

All Implemented Interfaces:

FeatureSource<SimpleFeatureType,SimpleFeature>, SimpleFeatureSource

Direct Known Subclasses:

JoiningJDBCFeatureSource

public class JDBCFeatureSource
extends ContentFeatureSource

Field Summary

Fields

Modifier and Type	Field	Description
static Hints.Key	FILTER_THREE_WAY_LOGIC	Add this hint to the query to force the filter to be interepreted as a three-way logic filter, where null values are treated as unknowns and propagate up the filter evaluation tree (e..g, A <> NULL -> NULL).

Fields inherited from class ContentFeatureSource

entry, hints, lock, query, queryCapabilities, schema, transaction

Constructor Summary

Constructors

Modifier	Constructor	Description
	JDBCFeatureSource(ContentEntry entry, Query query)	Creates the new feature store.
protected	JDBCFeatureSource(JDBCFeatureSource featureSource)	Copy existing feature source

Method Summary

Modifier and Type	Method	Description
protected void	addHints(Set<Hints.Key> hints)	Subclass hook too add additional hints.
protected SimpleFeatureType	buildFeatureType()	Builds the feature type from database metadata.
protected QueryCapabilities	buildQueryCapabilities()	Builds the query capabilities for this feature source.
protected boolean	canFilter(Query query)	Determines if the datastore can natively perform a filtering.
protected boolean	canLimit(Query query)	Determines if the datastore can natively limit the number of features returned in a query.
protected boolean	canOffset(Query query)	Determines if the datastore can natively skip the first offset number of features returned in a query.
protected boolean	canRetype(Query query)	Determines if the datastore can natively perform "retyping" which includes limiting the number of attributes returned and reordering of those attributes
protected boolean	canSort(Query query)	Determines if the datastore can natively perform sorting.
protected boolean	canTransact()	Determines if the store can natively manage transactions.
protected ReferencedEnvelope	getBoundsInternal(Query query)	Calculates the bounds of a specified query.
protected int	getCountInternal(Query query)	Calculates the number of features of a specified query.
JDBCDataStore	getDataStore()	Type narrow to JDBCDataStore.
PrimaryKey	getPrimaryKey()	Returns the primary key of the table backed by feature store.
protected FeatureReader<SimpleFeatureType,SimpleFeature>	getReaderInternal(Query query)	Subclass method for returning a native reader from the datastore.
JDBCState	getState()	Type narrow to JDBCState.
protected boolean	handleVisitor(Query query, FeatureVisitor visitor)	Subclass method which allows subclasses to natively handle a visitor.
boolean	isExposePrimaryKeyColumns()	The flag which will expose columns which compose a tables identifying or primary key, through feature type attributes.
void	setExposePrimaryKeyColumns(boolean exposePrimaryKeyColumns)	Sets the flag which will expose columns which compose a tables identifying or primary key, through feature type attributes.
protected Filter[]	splitFilter(Filter original)	Helper method for splitting a filter.
protected Filter[]	splitFilter(Filter original, Hints hints)

Methods inherited from class ContentFeatureSource

accepts, addFeatureListener, canEvent, canFilter, canLimit, canLock, canOffset, canReproject, canRetype, canSort, doLockInternal, doUnlockInternal, getAbsoluteSchema, getBounds, getBounds, getCount, getEntry, getFeatures, getFeatures, getFeatures, getInfo, getName, getQueryCapabilities, getReader, getReader, getReader, getSchema, getSupportedHints, getTransaction, getView, getView, isView, joinQuery, lockFeatures, lockFeatures, lockFeatures, processLock, removeFeatureListener, resolvePropertyNames, resolvePropertyNames, setFeatureLock, setTransaction, unLockFeatures, unLockFeatures, unLockFeatures

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

FILTER_THREE_WAY_LOGIC

public static final Hints.Key FILTER_THREE_WAY_LOGIC

Add this hint to the query to force the filter to be interepreted as a three-way logic filter, where null values are treated as unknowns and propagate up the filter evaluation tree (e..g, A <> NULL -> NULL). By default, the encoding is performed using two-way logic, where null values are treated as legitimate values (like null in Java). Also, warning: the hint cannot be provided to FeatureStore.removeFeatures(Filter) as that only gets a Filter object, rather than a query object.

Constructor Detail

JDBCFeatureSource

public JDBCFeatureSource(ContentEntry entry,
                         Query query)
                  throws IOException

Creates the new feature store.

Parameters:

entry - The datastore entry.

query - The defining query.

Throws:

IOException

JDBCFeatureSource

protected JDBCFeatureSource(JDBCFeatureSource featureSource)
                     throws IOException

Copy existing feature source

Parameters:

featureSource - jdbc feature source

Throws:

IOException

Method Detail

buildQueryCapabilities

protected QueryCapabilities buildQueryCapabilities()

Description copied from class: ContentFeatureSource

Builds the query capabilities for this feature source. The default implementation returns a newly built QueryCapabilities, subclasses are advised to build their own.

Overrides:

buildQueryCapabilities in class ContentFeatureSource

addHints

protected void addHints(Set<Hints.Key> hints)

Description copied from class: ContentFeatureSource

Subclass hook too add additional hints.

By default, the followings are already present:

• Hints.JTS_COORDINATE_SEQUENCE_FACTORY
• Hints.JTS_GEOMETRY_FACTORY

Overrides:

addHints in class ContentFeatureSource

Parameters:

hints - The set of hints supported by the feature source.

getDataStore

public JDBCDataStore getDataStore()

Type narrow to JDBCDataStore.

Specified by:

getDataStore in interface FeatureSource<SimpleFeatureType,SimpleFeature>

Overrides:

getDataStore in class ContentFeatureSource

Returns:

the data source providing this FeatureSource

getState

public JDBCState getState()

Type narrow to JDBCState.

Overrides:

getState in class ContentFeatureSource

getPrimaryKey

public PrimaryKey getPrimaryKey()

Returns the primary key of the table backed by feature store.

setExposePrimaryKeyColumns

public void setExposePrimaryKeyColumns(boolean exposePrimaryKeyColumns)

Sets the flag which will expose columns which compose a tables identifying or primary key, through feature type attributes.

Note: setting this flag which affect all feature sources created from or working against the current transaction.

isExposePrimaryKeyColumns

public boolean isExposePrimaryKeyColumns()

The flag which will expose columns which compose a tables identifying or primary key, through feature type attributes.

buildFeatureType

protected SimpleFeatureType buildFeatureType()
                                      throws IOException

Builds the feature type from database metadata.

Specified by:

buildFeatureType in class ContentFeatureSource

Throws:

IOException

splitFilter

protected Filter[] splitFilter(Filter original)

Helper method for splitting a filter.

splitFilter

protected Filter[] splitFilter(Filter original,
                               Hints hints)

getCountInternal

protected int getCountInternal(Query query)
                        throws IOException

Description copied from class: ContentFeatureSource

Calculates the number of features of a specified query. Subclasses must implement this method. If the computation is not fast, it's possible to return -1.

Specified by:

getCountInternal in class ContentFeatureSource

Throws:

IOException

getBoundsInternal

protected ReferencedEnvelope getBoundsInternal(Query query)
                                        throws IOException

Description copied from class: ContentFeatureSource

Calculates the bounds of a specified query. Subclasses must implement this method. If the computation is not fast, subclasses can return null.

Specified by:

getBoundsInternal in class ContentFeatureSource

Throws:

IOException

canFilter

protected boolean canFilter(Query query)

Description copied from class: ContentFeatureSource

Determines if the datastore can natively perform a filtering.

If the subclass can handle filtering natively it should override this method to return true. In this case it must do the filtering or throw an exception. This includes the case of partial native filtering where the datastore can only handle part of the filter natively. In these cases it is up to the subclass to apply a decorator to the reader it returns which will handle any part of the filter can was not applied natively. See FilteringFeatureReader.

Not overriding this method or returning false will cause the feature reader created by the subclass to be wrapped in a filtering feature reader when the query specifies a filter. See FilteringFeatureReader.

Overrides:

canFilter in class ContentFeatureSource

canSort

protected boolean canSort(Query query)

Description copied from class: ContentFeatureSource

Determines if the datastore can natively perform sorting.

If the subclass can handle retyping natively it should override this method to return true. In this case it must do the retyping or throw an exception.

Not overriding this method or returning false will cause an exception to be thrown when the query specifies sorting.

Overrides:

canSort in class ContentFeatureSource

See Also:

SortedFeatureReader

canRetype

protected boolean canRetype(Query query)

Description copied from class: ContentFeatureSource

Determines if the datastore can natively perform "retyping" which includes limiting the number of attributes returned and reordering of those attributes

If the subclass can handle retyping natively it should override this method to return true. In this case it must do the retyping or throw an exception.

Not overriding this method or returning false will cause the feature reader created by the subclass to be wrapped in a retyping feature reader when the query specifies a retype.

Overrides:

canRetype in class ContentFeatureSource

See Also:

ReTypeFeatureReader

canLimit

protected boolean canLimit(Query query)

Description copied from class: ContentFeatureSource

Determines if the datastore can natively limit the number of features returned in a query.

If the subclass can handle a map feature cap natively then it should override this method to return true. In this case it must do the cap or throw an exception.

Not overriding this method or returning false will case the feature reader created by the subclass to be wrapped in a max feature capping decorator when the query specifies a max feature cap.

Overrides:

canLimit in class ContentFeatureSource

See Also:

MaxFeatureReader

canOffset

protected boolean canOffset(Query query)

Description copied from class: ContentFeatureSource

Determines if the datastore can natively skip the first offset number of features returned in a query.

If the subclass can handle a map feature cap natively then it should override this method to return true. In this case it must do the cap or throw an exception.

Not overriding this method or returning false will case the feature reader created by the subclass to be accessed offset times before being returned to the caller.

Overrides:

canOffset in class ContentFeatureSource

canTransact

protected boolean canTransact()

Description copied from class: ContentFeatureSource

Determines if the store can natively manage transactions.

If a subclass can handle transactions natively it should override this method to return true and deal with transactions on its own, including firing feature modifications events.

Overrides:

canTransact in class ContentFeatureSource

Returns:

true if transaction independence has custom implementation

getReaderInternal

protected FeatureReader<SimpleFeatureType,SimpleFeature> getReaderInternal(Query query)
                                                                          throws IOException

Description copied from class: ContentFeatureSource

Subclass method for returning a native reader from the datastore.

It is important to note that if the native reader intends to handle any of the following natively:

• reprojection
• filtering
• max feature limiting
• sorting
• locking
• transactions

Then it *must* set the corresponding flags to true:

• ContentFeatureSource.canReproject() - handles Query.getCoordinateSystemReproject() internally. Example would be PostGIS using Proj to handle reproejction internally
• ContentFeatureSource.canFilter(Query) - handles internally.
• {@link #canLimit(Query)} - handles {@link Query#getMaxFeatures()} and {@link Query#getStartIndex()} internally.
• {@link #canSort(Query)} - handles {@link Query#getSortBy()} natively.
• {@link #canRetype(Query)} - handles {@link Query#getProperties()} natively. Example would be only parsing the properties the user asks for from an XML file
• {@link #canLock()} - handles read-locks natively
• {@link #canTransact()} - handles transactions natively

Specified by:

getReaderInternal in class ContentFeatureSource

Throws:

IOException

handleVisitor

protected boolean handleVisitor(Query query,
                                FeatureVisitor visitor)
                         throws IOException

Description copied from class: ContentFeatureSource

Subclass method which allows subclasses to natively handle a visitor.

Subclasses would override this method and return true in cases where the specific visitor could be handled without iterating over the entire result set of query. An example would be handling visitors that calculate aggregate values.

Overrides:

handleVisitor in class ContentFeatureSource

Parameters:

query - The query being made.

visitor - The visitor to

Returns:

true if the visitor can be handled natively, otherwise false.

Throws:

IOException