/*
* Geotoolkit - An Open Source Java GIS Toolkit
* http://www.geotoolkit.org
*
* (C) 2003-2008, Open Source Geospatial Foundation (OSGeo)
* (C) 2009, Geomatys
*
* 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.geotoolkit.data.memory;
import java.util.NoSuchElementException;
import org.geotoolkit.data.FeatureCollection;
import org.geotoolkit.data.FeatureIterator;
import org.geotoolkit.data.FeatureReader;
import org.geotoolkit.data.FeatureStoreRuntimeException;
import org.geotoolkit.data.FeatureWriter;
import org.geotoolkit.factory.Hints;
import org.apache.sis.util.Classes;
import org.opengis.feature.Feature;
import org.opengis.feature.FeatureType;
/**
* Basic support for a FeatureIterator that limits itself to a given number of features.
*
* @author Chris Holmes
* @author Johann Sorel (Geomatys)
* @module
*/
public class GenericMaxFeatureIterator<R extends FeatureIterator> implements FeatureIterator {
protected final R iterator;
protected final int maxFeatures;
private int counter = 0;
/**
* Creates a new instance of GenericMaxFeatureIterator
*
* @param iterator FeatureReader to limit
* @param maxFeatures maximum number of feature
*/
private GenericMaxFeatureIterator(final R iterator, final int maxFeatures) {
this.iterator = iterator;
this.maxFeatures = maxFeatures;
}
/**
* {@inheritDoc }
*/
@Override
public Feature next() throws FeatureStoreRuntimeException {
if (hasNext()) {
counter++;
return iterator.next();
} else {
throw new NoSuchElementException("No such Feature exists");
}
}
/**
* {@inheritDoc }
*/
@Override
public void close() throws FeatureStoreRuntimeException {
iterator.close();
}
/**
* @return <code>true</code> if the featureReader has not passed the max
* and still has more features.
* @throws IOException If the reader we are filtering encounters a problem
*/
@Override
public boolean hasNext() throws FeatureStoreRuntimeException {
return ((counter < maxFeatures) && iterator.hasNext());
}
/**
* {@inheritDoc }
*/
@Override
public void remove() {
iterator.remove();
}
@Override
public String toString() {
final StringBuilder sb = new StringBuilder(Classes.getShortClassName(this));
sb.append("[Max=").append(maxFeatures).append("]\n");
String subIterator = "\u2514\u2500\u2500" + iterator.toString(); //move text to the right
subIterator = subIterator.replaceAll("\n", "\n\u00A0\u00A0\u00A0"); //move text to the right
sb.append(subIterator);
return sb.toString();
}
/**
* Wrap a FeatureReader with a max limit.
*
*/
private static final class GenericMaxFeatureReader extends GenericMaxFeatureIterator<FeatureReader> implements FeatureReader{
private GenericMaxFeatureReader(final FeatureReader reader,final int limit){
super(reader,limit);
}
@Override
public FeatureType getFeatureType() {
return iterator.getFeatureType();
}
}
/**
* Wrap a FeatureWriter with a max limit.
*
*/
private static final class GenericMaxFeatureWriter extends GenericMaxFeatureIterator<FeatureWriter> implements FeatureWriter{
private GenericMaxFeatureWriter(final FeatureWriter writer,final int limit){
super(writer,limit);
}
@Override
public FeatureType getFeatureType() {
return iterator.getFeatureType();
}
@Override
public void write() throws FeatureStoreRuntimeException {
iterator.write();
}
}
private static final class GenericMaxFeatureCollection extends WrapFeatureCollection{
private final int max;
private GenericMaxFeatureCollection(final FeatureCollection original, final int max){
super(original);
this.max = max;
}
@Override
public FeatureIterator iterator(final Hints hints) throws FeatureStoreRuntimeException {
return wrap(getOriginalFeatureCollection().iterator(hints), max);
}
@Override
protected Feature modify(Feature original) throws FeatureStoreRuntimeException {
throw new UnsupportedOperationException("should not have been called.");
}
}
/**
* Wrap a FeatureReader with a max limit.
*/
public static FeatureIterator wrap(final FeatureIterator reader, final int limit){
if(limit==Integer.MAX_VALUE) return reader;
if(reader instanceof FeatureReader){
return wrap((FeatureReader)reader,limit);
}else if(reader instanceof FeatureWriter){
return wrap((FeatureWriter)reader,limit);
}else{
return new GenericMaxFeatureIterator(reader, limit);
}
}
/**
* Wrap a FeatureReader with a max limit.
*/
public static FeatureReader wrap(final FeatureReader reader, final int limit){
if(limit==Integer.MAX_VALUE) return reader;
return new GenericMaxFeatureReader(reader, limit);
}
/**
* Wrap a FeatureWriter with a max limit.
*/
public static FeatureWriter wrap(final FeatureWriter writer, final int limit){
if(limit==Integer.MAX_VALUE) return writer;
return new GenericMaxFeatureWriter(writer, limit);
}
/**
* Create an limited FeatureCollection wrapping the given collection.
*/
public static FeatureCollection wrap(final FeatureCollection original, final int max){
if(max==Integer.MAX_VALUE) return original;
return new GenericMaxFeatureCollection(original, max);
}
}