/**
* '$RCSfile$'
* Copyright: 2000 Regents of the University of California and the
* National Center for Ecological Analysis and Synthesis
*
* Author: Matthew Perry
* '$Date$'
* '$Revision$'
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package edu.ucsb.nceas.metacat.spatial;
import org.geotools.data.shapefile.ShapefileDataStore;
import org.geotools.data.FeatureStore;
import org.geotools.data.FeatureSource;
import org.geotools.data.DefaultTransaction;
import org.geotools.data.Transaction;
import org.geotools.filter.Filter;
import org.geotools.filter.AbstractFilter;
import org.geotools.filter.Expression;
import org.geotools.filter.CompareFilter;
import org.geotools.filter.GeometryFilter;
import org.geotools.filter.FilterFactory;
import org.geotools.filter.FilterFactoryFinder;
import org.geotools.filter.IllegalFilterException;
import org.geotools.feature.FeatureCollection;
import org.geotools.feature.FeatureCollections;
import org.opengis.feature.simple.SimpleFeature;
import org.opengis.feature.simple.SimpleFeatureType;
import com.vividsolutions.jts.geom.Envelope;
import com.vividsolutions.jts.geom.Geometry;
import com.vividsolutions.jts.geom.GeometryFactory;
import com.vividsolutions.jts.geom.Polygon;
import com.vividsolutions.jts.geom.Coordinate;
import java.io.File;
import java.net.URI;
import java.net.URL;
import java.net.MalformedURLException;
import java.sql.ResultSet;
import java.sql.PreparedStatement;
import java.util.Vector;
import java.util.Iterator;
import java.io.IOException;
import org.apache.log4j.Logger;
import edu.ucsb.nceas.metacat.util.MetacatUtil;
/**
* Class to query the persistent spatial cache
* and returns docids matching spatial constraints
*/
public class SpatialQuery {
private static Logger log = Logger.getLogger(SpatialQuery.class.getName());
/**
* empty constructor to initialize spatial query
*/
public SpatialQuery() { }
/**
* Querys all features in the spatial cache
* and filters based on bouding coordinates.
* Returns Vector of docids.
*
* @param w West bounding coordinate
* @param s South bounding coordinate
* @param e East bounding coordinate
* @param n North bounding coordinate
*
*/
public Vector<String> filterByBbox( float w, float s, float e, float n ) {
Vector<String> docids = new Vector<String>();
SpatialFeatureSchema featureSchema = new SpatialFeatureSchema();
ShapefileDataStore store = null;
FeatureSource features = null;
FeatureCollection collection = null;
FilterFactory filterFactory = FilterFactoryFinder.createFilterFactory();
try {
// read the spatial cache (polygons)
store = new ShapefileDataStore( (new File( featureSchema.polygonShpUri )).toURL() );
features = store.getFeatureSource(store.getTypeNames()[0]);
// Construct bounding box
Envelope envelope = new Envelope( w, e, s, n );
Expression bbox = filterFactory.createBBoxExpression( envelope );
// Construct the bbox as an actual geometry
Coordinate[] linestringCoordinates = new Coordinate[5];
linestringCoordinates[0] = new Coordinate( w, s );
linestringCoordinates[1] = new Coordinate( w, n );
linestringCoordinates[2] = new Coordinate( e, n );
linestringCoordinates[3] = new Coordinate( e, s );
linestringCoordinates[4] = new Coordinate( w, s );
GeometryFactory geomFac = new GeometryFactory();
Polygon bboxGeom = geomFac.createPolygon( geomFac.createLinearRing(linestringCoordinates), null);
// Set up geometry filter based on bbox
SimpleFeatureType featureType = store.getSchema( store.getTypeNames()[0] );
Expression geometry = filterFactory.createAttributeExpression( featureType.getGeometryDescriptor().getName().toString());
GeometryFilter bboxFilter = filterFactory.createGeometryFilter(AbstractFilter.GEOMETRY_BBOX);
bboxFilter.addLeftGeometry( geometry );
bboxFilter.addRightGeometry( bbox );
// Iterate through the filtered feature collection
// and add matches to the docid Vector
collection = features.getFeatures(bboxFilter);
Iterator iterator = collection.iterator();
try {
for( Iterator i=collection.iterator(); i.hasNext(); ) {
SimpleFeature feature = (SimpleFeature) i.next();
Geometry geom = (Geometry)feature.getAttribute(0);
if ( geom.within( bboxGeom ) ) {
// assumes docid is attribute number 1
// in a zero-based index of dbf columns
docids.add( (String) feature.getAttribute(1) );
}
}
} finally {
collection.close( iterator );
}
/*
* Also query the point cache since there may be point-only documents
* Filter by the bbox AND check against docids Vector so that
* docids already in the Vector don't get duplicated.
*/
// read the spatial cache (points)
store = new ShapefileDataStore( (new File( featureSchema.pointShpUri )).toURL() );
features = store.getFeatureSource(store.getTypeNames()[0]);
// Set up geometry filter based on bbox
featureType = store.getSchema( store.getTypeNames()[0] );
geometry = filterFactory.createAttributeExpression( featureType.getGeometryDescriptor().getName().toString() );
bboxFilter = filterFactory.createGeometryFilter(AbstractFilter.GEOMETRY_BBOX);
bboxFilter.addLeftGeometry( geometry );
bboxFilter.addRightGeometry( bbox );
// Iterate through the filtered feature collection
// and add matches to the docid Vector IF
// they aren't already present
collection = features.getFeatures(bboxFilter);
iterator = collection.iterator();
String docid = null;
try {
for( Iterator i=collection.iterator(); i.hasNext(); ) {
SimpleFeature feature = (SimpleFeature) i.next();
Geometry geom = (Geometry)feature.getAttribute(0);
if ( geom.intersects( bboxGeom ) ) {
// assumes docid is attribute number 1
// in a zero-based index of dbf columns
docid = (String) feature.getAttribute(1);
if( !docids.contains( docid ) ) {
docids.add( docid );
}
}
}
} finally {
collection.close( iterator );
}
} catch (MalformedURLException ex) {
ex.printStackTrace();
} catch (IOException ex) {
ex.printStackTrace();
} catch (IllegalFilterException ex) {
ex.printStackTrace();
}
return docids;
}
}