Package org.geotools.data

Class DiffFeatureWriter

Object

DiffFeatureWriter

All Implemented Interfaces:

Closeable, AutoCloseable, FeatureWriter<SimpleFeatureType,SimpleFeature>

public abstract class DiffFeatureWriter
extends Object
implements FeatureWriter<SimpleFeatureType,SimpleFeature>

A FeatureWriter that captures modifications against a FeatureReader.

You will eventually need to write out the differences, later.

The api has been implemented in terms of FeatureReader<SimpleFeatureType, SimpleFeature> to make explicit that no Features are writen out by this Class.

Author:

Jody Garnett, Refractions Research

See Also:

• TransactionStateDiff

Field Summary

Fields

Modifier and Type	Field	Description
protected Diff	diff
protected FeatureReader<SimpleFeatureType,SimpleFeature>	reader

Constructor Summary

Constructors

Constructor	Description
DiffFeatureWriter(FeatureReader<SimpleFeatureType,SimpleFeature> reader, Diff diff)	DiffFeatureWriter construction.
DiffFeatureWriter(FeatureReader<SimpleFeatureType,SimpleFeature> reader, Diff diff, Filter filter)	DiffFeatureWriter construction.

Method Summary

Modifier and Type	Method	Description
void	close()	Clean up resources associated with this writer.
protected abstract void	fireNotification(int eventType, ReferencedEnvelope bounds)	Subclass must provide the notification.
SimpleFeatureType	getFeatureType()	Supplys FeatureTypeFrom reader
boolean	hasNext()	Query for more content.
SimpleFeature	next()	Next Feature from reader or new content.
void	remove()	Removes current Feature, must be called before hasNext.
void	write()	Writes out the current feature.

Methods inherited from class Object

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

Field Details

reader

protected FeatureReader<SimpleFeatureType,SimpleFeature> reader

diff

protected Diff diff

Constructor Details

DiffFeatureWriter

public DiffFeatureWriter(FeatureReader<SimpleFeatureType,SimpleFeature> reader,
 Diff diff)

DiffFeatureWriter construction.

DiffFeatureWriter

public DiffFeatureWriter(FeatureReader<SimpleFeatureType,SimpleFeature> reader,
 Diff diff,
 Filter filter)

DiffFeatureWriter construction.

Method Details

getFeatureType

public SimpleFeatureType getFeatureType()

Supplys FeatureTypeFrom reader

Specified by:

getFeatureType in interface FeatureWriter<SimpleFeatureType,SimpleFeature>

Returns:

FeatureType this writer has been configured to create.

See Also:

• FeatureWriter.getFeatureType()

next

public SimpleFeature next()
                   throws IOException

Next Feature from reader or new content.

Specified by:

next in interface FeatureWriter<SimpleFeatureType,SimpleFeature>

Returns:

Feature from Query, or newly appended Feature

Throws:

IOException - if the writer has been closed or an I/O error occurs reading the next Feature.

See Also:

• FeatureWriter.next()

remove

public void remove()
            throws IOException

Description copied from interface: FeatureWriter

Removes current Feature, must be called before hasNext.

FeatureWriters will need to allow all FeatureSources of the same typeName to issue a FeatureEvent event of type FeatureEvent.FEATURES_REMOVED when this method is called.

If this FeatureWriter is opperating against a Transaction FEATURES_REMOVED events should only be sent to FeatureSources operating on the same Transaction. When Transaction commit() is called other FeatureSources will be informed of the modifications.

When the current Feature has been provided as new content, this method "cancels" the add opperation (and notification needed).

Specified by:

remove in interface FeatureWriter<SimpleFeatureType,SimpleFeature>

Throws:

IOException

See Also:

• FeatureWriter.remove()

write

public void write()
           throws IOException

Writes out the current feature.

Specified by:

write in interface FeatureWriter<SimpleFeatureType,SimpleFeature>

Throws:

IOException

See Also:

• FeatureWriter.write()

hasNext

public boolean hasNext()
                throws IOException

Query for more content.

Specified by:

hasNext in interface FeatureWriter<SimpleFeatureType,SimpleFeature>

Returns:

true if an additional Feature is available, false if not.

Throws:

IOException - if an I/O error occurs.

See Also:

• FeatureWriter.hasNext()

close

public void close()
           throws IOException

Clean up resources associated with this writer.

Diff is not clear()ed as it is assumed that it belongs to a Transaction.State object and may yet be written out.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in interface FeatureWriter<SimpleFeatureType,SimpleFeature>

Throws:

IOException - if there there are problems releasing underlying resources, or possibly if close has been called (up to the implementation).

See Also:

• FeatureWriter.close()

fireNotification

protected abstract void fireNotification(int eventType,
 ReferencedEnvelope bounds)

Subclass must provide the notification.

Notification requirements for modifications against a Transaction should only be issued to SimpleFeatureSource instances that opperate against the same typeName and Transaction.

Other SimpleFeatureSource instances with the same typeName will be notified when the Transaction is committed.

Parameters:

eventType - One of FeatureType.FEATURES_ADDED, FeatureType.CHANGED, FeatureType.FEATURES_REMOVED