/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2005-2008, 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.collection;
import java.io.IOException;
import java.util.Iterator;
import org.geotools.data.AbstractDataStore;
import org.geotools.data.DataSourceException;
import org.geotools.data.FeatureReader;
import org.geotools.data.Query;
import org.geotools.data.SchemaNotFoundException;
import org.geotools.data.Transaction;
import org.geotools.data.simple.SimpleFeatureCollection;
import org.geotools.feature.CollectionEvent;
import org.geotools.feature.CollectionListener;
import org.geotools.feature.FeatureCollection;
import org.geotools.feature.FeatureCollections;
import org.geotools.feature.FeatureIterator;
import org.geotools.feature.FeatureTypes;
import org.geotools.geometry.jts.ReferencedEnvelope;
import org.opengis.feature.simple.SimpleFeature;
import org.opengis.feature.simple.SimpleFeatureType;
import org.opengis.filter.Filter;
import com.vividsolutions.jts.geom.Geometry;
/**
* Simple data store wrapper for feature collections. Allows to use feature collections in the user
* interface layer and everything else where a data store or a feature source is needed.
*
* @source $URL$
*/
public class CollectionDataStore extends AbstractDataStore {
SimpleFeatureType featureType;
FeatureCollection<SimpleFeatureType,SimpleFeature> collection;
/**
* Builds a data store wrapper around an empty collection.
*
* @param collection
*/
public CollectionDataStore(SimpleFeatureType schema) {
this.collection = FeatureCollections.newCollection();
this.featureType = schema;
collection.addListener(new FeatureCollectionListener());
}
/**
* Builds a data store wrapper on top of a feature collection
*
* @param collection
*/
public CollectionDataStore(FeatureCollection<SimpleFeatureType,SimpleFeature> collection) {
this.collection = collection;
if (collection.size() == 0) {
this.featureType = FeatureTypes.EMPTY;
} else {
this.featureType = collection.getSchema();
// Iterator iter = null;
// try {
// iter = collection.iterator();
// this.featureType = ((SimpleFeature) iter.next()).getFeatureType();
// } finally {
// if (iter != null)
// collection.close(iter);
// }
}
collection.addListener(new FeatureCollectionListener());
}
/**
* @see org.geotools.data.DataStore#getTypeNames()
*/
public String[] getTypeNames() {
return new String[] { featureType.getTypeName() };
}
/**
* @see org.geotools.data.DataStore#getSchema(java.lang.String)
*/
public SimpleFeatureType getSchema(String typeName) throws IOException {
if ((typeName != null) && typeName.equals(featureType.getTypeName())) {
return featureType;
}
throw new IOException(typeName + " not available");
}
/**
* Provides FeatureReader<SimpleFeatureType, SimpleFeature> over the entire contents of <code>typeName</code>.
*
* <p>
* Implements getFeatureReader contract for AbstractDataStore.
* </p>
*
* @param typeName
*
*
* @throws IOException If typeName could not be found
* @throws DataSourceException See IOException
*
* @see org.geotools.data.AbstractDataStore#getFeatureSource(java.lang.String)
*/
public FeatureReader<SimpleFeatureType, SimpleFeature> getFeatureReader(final String typeName)
throws IOException {
return new DelegateFeatureReader<SimpleFeatureType, SimpleFeature>( getSchema(typeName), collection.features() );
}
/**
* Returns the feature collection held by this data store
*
*/
public FeatureCollection<SimpleFeatureType,SimpleFeature> getCollection() {
return (SimpleFeatureCollection) collection;
}
/**
* @throws SchemaNotFoundException
* @see org.geotools.data.AbstractDataStore#getBounds(java.lang.String,
* org.geotools.data.Query)
*/
protected ReferencedEnvelope getBounds(Query query) throws SchemaNotFoundException{
String featureTypeName = query.getTypeName();
if (!featureType.getTypeName().equals(featureTypeName)) {
throw new SchemaNotFoundException(featureTypeName);
}
return getBoundsInternal(query);
}
/**
* @param query
*/
protected ReferencedEnvelope getBoundsInternal(Query query) {
FeatureIterator<SimpleFeature> iterator = collection.features();
ReferencedEnvelope envelope = new ReferencedEnvelope( featureType.getCoordinateReferenceSystem() );
if (iterator.hasNext()) {
int count = 1;
Filter filter = query.getFilter();
while (iterator.hasNext() && (count < query.getMaxFeatures())) {
SimpleFeature feature = iterator.next();
if (filter.evaluate(feature)) {
count++;
envelope.expandToInclude(((Geometry)feature.getDefaultGeometry()).getEnvelopeInternal());
}
}
}
return envelope;
}
/**
* @see org.geotools.data.AbstractDataStore#getCount(java.lang.String, org.geotools.data.Query)
*/
protected int getCount(Query query)
throws IOException {
String featureTypeName = query.getTypeName();
if (!featureType.getTypeName().equals(featureTypeName)) {
throw new SchemaNotFoundException(featureTypeName);
}
int count = 0;
FeatureIterator<SimpleFeature> iterator = collection.features();
Filter filter = query.getFilter();
while (iterator.hasNext() && (count < query.getMaxFeatures())) {
if (filter.evaluate(iterator.next())) {
count++;
}
}
return count;
}
/**
* Simple listener that forwards collection events into data store events
*
* @author aaime
*/
private class FeatureCollectionListener implements CollectionListener {
public void collectionChanged(CollectionEvent tce) {
String typeName = featureType.getTypeName();
ReferencedEnvelope bounds = null;
bounds = getBoundsInternal(Query.ALL);
switch (tce.getEventType()) {
case CollectionEvent.FEATURES_ADDED:
listenerManager.fireFeaturesAdded(typeName, Transaction.AUTO_COMMIT, bounds, false);
break;
case CollectionEvent.FEATURES_CHANGED:
listenerManager.fireFeaturesChanged(typeName, Transaction.AUTO_COMMIT, bounds, false);
break;
case CollectionEvent.FEATURES_REMOVED:
listenerManager.fireFeaturesRemoved(typeName, Transaction.AUTO_COMMIT, bounds, false);
break;
}
}
}
}