Package org.geotools.data.memory

Class MemoryFeatureSource

Object

ContentFeatureSource

MemoryFeatureSource

All Implemented Interfaces:

FeatureSource<SimpleFeatureType,SimpleFeature>, SimpleFeatureSource

public class MemoryFeatureSource
extends ContentFeatureSource

Read access to feature content held in memory.

Author:

Jody Garnett (Boundless)

Field Summary

Fields inherited from class ContentFeatureSource

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

Constructor Summary

Constructors

Constructor	Description
MemoryFeatureSource(ContentEntry entry)
MemoryFeatureSource(ContentEntry entry, Query query)

Method Summary

Modifier and Type	Method	Description
protected SimpleFeatureType	buildFeatureType()	Creates the feature type or schema for the feature source.
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.
MemoryDataStore	getDataStore()	Access parent MemoryDataStore.
MemoryEntry	getEntry()	The entry for the feature source.
protected FeatureReader<SimpleFeatureType,SimpleFeature>	getReaderInternal(Query query)	Subclass method for returning a native reader from the datastore.
MemoryState	getState()	The current state for the feature source.
protected boolean	handleVisitor(Query query, FeatureVisitor visitor)	Subclass method which allows subclasses to natively handle a visitor.

Methods inherited from class ContentFeatureSource

accepts, addFeatureListener, addHints, buildQueryCapabilities, canEvent, canFilter, canFilter, canLimit, canLimit, canLock, canOffset, canOffset, canReproject, canRetype, canRetype, canSort, canSort, canTransact, doLockInternal, doUnlockInternal, getAbsoluteSchema, getBounds, getBounds, getCount, 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

Constructor Detail

MemoryFeatureSource

public MemoryFeatureSource(ContentEntry entry)

MemoryFeatureSource

public MemoryFeatureSource(ContentEntry entry,
                           Query query)

Method Detail

getDataStore

public MemoryDataStore getDataStore()

Access parent MemoryDataStore.

Specified by:

getDataStore in interface FeatureSource<SimpleFeatureType,SimpleFeature>

Overrides:

getDataStore in class ContentFeatureSource

Returns:

the data source providing this FeatureSource

getState

public MemoryState getState()

Description copied from class: ContentFeatureSource

The current state for the feature source.

This value is derived from current transaction of the feature source.

Overrides:

getState in class ContentFeatureSource

getEntry

public MemoryEntry getEntry()

The entry for the feature source.

Overrides:

getEntry in class ContentFeatureSource

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

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

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

buildFeatureType

protected SimpleFeatureType buildFeatureType()

Description copied from class: ContentFeatureSource

Creates the feature type or schema for the feature source.

Implementations should use SimpleFeatureTypeBuilder to build the feature type. Also, the builder should be injected with the feature factory which has been set on the DataStore (see ContentDataStore.getFeatureFactory(). Example:

   SimpleFeatureTypeBuilder b = new SimpleFeatureTypeBuilder();
   b.setFeatureTypeFactory( getDataStore().getFeatureTypeFactory() );

   //build the feature type
   ...
 

Specified by:

buildFeatureType in class ContentFeatureSource

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