Package org.geotools.data

Class FilteringFeatureWriter

Object

FilteringFeatureWriter

All Implemented Interfaces:

Closeable, AutoCloseable, FeatureWriter<SimpleFeatureType,SimpleFeature>

public class FilteringFeatureWriter
extends Object
implements FeatureWriter<SimpleFeatureType,SimpleFeature>

Filtering is performed on this hasNext() method.

This implementation writes out content furing the hasNext() method. This allows the implementation to "peek" ahead.

This FeatureWriter does not support the addition of new content.

Author:

Jody Garnett, Refractions Research

Constructor Summary

Constructors

Constructor	Description
FilteringFeatureWriter(FeatureWriter<SimpleFeatureType,SimpleFeature> writer, Filter filter)

Method Summary

Modifier and Type	Method	Description
void	close()	Release the underlying resources.
SimpleFeatureType	getFeatureType()	FeatureType this reader has been configured to create.
boolean	hasNext()	Query if we have more content.
SimpleFeature	next()	Reads a Feature from the underlying AttributeReader.
void	remove()	Removes current Feature, must be called before hasNext.
void	write()	Writes the current Feature, must be called before hasNext.

Methods inherited from class Object

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

Constructor Detail

FilteringFeatureWriter

public FilteringFeatureWriter(FeatureWriter<SimpleFeatureType,SimpleFeature> writer,
                              Filter filter)

Method Detail

getFeatureType

public SimpleFeatureType getFeatureType()

Description copied from interface: FeatureWriter

FeatureType this reader has been configured to create.

Specified by:

getFeatureType in interface FeatureWriter<SimpleFeatureType,SimpleFeature>

Returns:

FeatureType this writer has been configured to create.

next

public SimpleFeature next()
                   throws IOException

Description copied from interface: FeatureWriter

Reads a Feature from the underlying AttributeReader.

This method may return a Feature even though hasNext() returns false, this allows FeatureWriters to provide an ability to append 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.

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

write

public void write()
           throws IOException

Description copied from interface: FeatureWriter

Writes the current Feature, must be called before hasNext.

FeautreWriters will need to allow FeatureSources of the same typeName to issue a FeatureEvent:

• FeatureEvent.FEATURES_ADDED: when next() has been called with hasNext() equal to false.
• FeatureEvent.FEATURES_MODIFIED: when next has been called with hasNext() equal to true and the resulting Feature has indeed been modified.

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

If you have not called write() when you call hasNext() or next(), no modification will occur().

Specified by:

write in interface FeatureWriter<SimpleFeatureType,SimpleFeature>

Throws:

IOException

hasNext

public boolean hasNext()
                throws IOException

Query if we have more content.

Specified by:

hasNext in interface FeatureWriter<SimpleFeatureType,SimpleFeature>

Returns:

true if writer has additional content

Throws:

IOException - If writer we are filtering encounters a problem

close

public void close()
           throws IOException

Description copied from interface: FeatureWriter

Release the underlying resources.

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).