org.geotools.data
Class FilteringFeatureWriter

java.lang.Object
  org.geotools.data.FilteringFeatureWriter

All Implemented Interfaces:

FeatureWriter

public class FilteringFeatureWriter

extends java.lang.Object

implements FeatureWriter

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

FilteringFeatureWriter(FeatureWriter writer, Filter filter)

Method Summary

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

Methods inherited from class java.lang.Object

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

Constructor Detail

FilteringFeatureWriter

public FilteringFeatureWriter(FeatureWriter writer,
                              Filter filter)

Method Detail

getFeatureType

public FeatureType getFeatureType()

Description copied from interface: FeatureWriter

FeatureType this reader has been configured to create.

Specified by:

getFeatureType in interface FeatureWriter

Returns:

FeatureType this writer has been configured to create.

next

public Feature next()
             throws java.io.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

Returns:

Feature from Query, or newly appended Feature

Throws:

java.io.IOException - DOCUMENT ME!

remove

public void remove()
            throws java.io.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

Throws:

java.io.IOException - DOCUMENT ME!

write

public void write()
           throws java.io.IOException

Description copied from interface: FeatureWriter

Wrties 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

Throws:

java.io.IOException

hasNext

public boolean hasNext()
                throws java.io.IOException

Query if we have more content.

Specified by:

hasNext in interface FeatureWriter

Returns:

true if writer has additional content

Throws:

java.io.IOException - If writer we are filtering encounters a problem

close

public void close()
           throws java.io.IOException

Description copied from interface: FeatureWriter

Release the underlying resources.

Specified by:

close in interface FeatureWriter

Throws:

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