/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2004-2008, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*/
package org.geotools.data.store;
import java.io.IOException;
import java.util.NoSuchElementException;
import org.geotools.data.FeatureReader;
import org.geotools.data.simple.SimpleFeatureIterator;
import org.geotools.feature.FeatureIterator;
import org.geotools.feature.IllegalAttributeException;
import org.opengis.feature.simple.SimpleFeature;
import org.opengis.feature.simple.SimpleFeatureType;
/**
* An iterator wrapper for a FeatureReader<SimpleFeatureType, SimpleFeature> - for use with
* an AbstractFeatureCollection.
* <p>
* There is no reason modify this class, subclasses that wish
* to work with a custom iterator need just that - a custom iterator.
* <p>
* @author jgarnett
* @since 2.1.RC0
* @source $URL$
*/
final class FeatureReaderFeatureIterator implements SimpleFeatureIterator {
FeatureReader<SimpleFeatureType, SimpleFeature> reader;
public FeatureReaderFeatureIterator( FeatureReader<SimpleFeatureType, SimpleFeature> reader ){
this.reader = reader;
}
public boolean hasNext() {
try {
if( reader == null ) return false;
if( reader.hasNext() ){
return true;
}
else {
// auto close because we don't trust
// client code to call closed :-)
close();
return false;
}
} catch (IOException e) {
close();
return false; // failure sounds like lack of next to me
}
}
public SimpleFeature next() {
if( reader == null ) {
throw new NoSuchElementException( "Iterator has been closed" );
}
try {
return reader.next();
} catch (IOException io) {
close();
NoSuchElementException problem = new NoSuchElementException( "Could not obtain the next feature:"+io );
problem.initCause( io );
throw problem;
} catch (IllegalAttributeException create) {
close();
NoSuchElementException problem = new NoSuchElementException( "Could not create the next feature:"+create );
problem.initCause( create );
throw problem;
}
}
/** If this is a problem, a different iterator can be made based on FeatureWriter */
public void remove() {
throw new UnsupportedOperationException("Modification of contents is not supported");
}
/**
* This method only needs package visability as only AbstractFeatureCollection
* is trusted enough to call it.
*/
public void close(){
if( reader != null){
try {
reader.close();
} catch (IOException e) {
// sorry but iterators die quitely in the night
}
reader = null;
}
}
};