/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2003-2008, 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.crs;
import java.io.IOException;
import java.util.Iterator;
import java.util.NoSuchElementException;
import org.geotools.data.DataSourceException;
import org.geotools.feature.FeatureIterator;
import org.geotools.feature.IllegalAttributeException;
import org.geotools.feature.simple.SimpleFeatureBuilder;
import org.geotools.geometry.jts.GeometryCoordinateSequenceTransformer;
import org.opengis.feature.simple.SimpleFeature;
import org.opengis.feature.simple.SimpleFeatureType;
import org.opengis.referencing.operation.MathTransform;
import org.opengis.referencing.operation.MathTransform2D;
import org.opengis.referencing.operation.TransformException;
import com.vividsolutions.jts.geom.Geometry;
/**
* ReprojectFeatureReader provides a reprojection for FeatureTypes.
*
* <p>
* ReprojectFeatureReader is a wrapper used to reproject GeometryAttributes
* to a user supplied CoordinateReferenceSystem from the original
* CoordinateReferenceSystem supplied by the original FeatureReader.
* </p>
*
* <p>
* Example Use:
* <pre><code>
* ReprojectFeatureReader reader =
* new ReprojectFeatureReader( originalReader, reprojectCS );
*
* CoordinateReferenceSystem originalCS =
* originalReader.getFeatureType().getDefaultGeometry().getCoordinateSystem();
*
* CoordinateReferenceSystem newCS =
* reader.getFeatureType().getDefaultGeometry().getCoordinateSystem();
*
* assertEquals( reprojectCS, newCS );
* </code></pre>
* </p>
* TODO: handle the case where there is more than one geometry and the other
* geometries have a different CS than the default geometry
*
* @author jgarnett, Refractions Research, Inc.
* @author aaime
* @author $Author: jive $ (last modification)
*
* @source $URL$
* @version $Id$
*/
public class ReprojectFeatureIterator implements Iterator {
FeatureIterator<SimpleFeature> reader;
SimpleFeatureType schema;
GeometryCoordinateSequenceTransformer transformer = new GeometryCoordinateSequenceTransformer();
public ReprojectFeatureIterator(FeatureIterator<SimpleFeature> reader, SimpleFeatureType schema,
MathTransform transform) {
this.reader = reader;
this.schema = schema;
transformer.setMathTransform((MathTransform2D)transform);
//set hte target coordinate system
transformer.setCoordinateReferenceSystem(schema.getCoordinateReferenceSystem());
}
/**
* Implement getFeatureType.
*
* <p>
* Description ...
* </p>
*
*
* @throws IllegalStateException DOCUMENT ME!
*
* @see org.geotools.data.FeatureReader#getFeatureType()
*/
public SimpleFeatureType getFeatureType() {
if (schema == null) {
throw new IllegalStateException("Reader has already been closed");
}
return schema;
}
/**
* Implement next.
*
* <p>
* Description ...
* </p>
*
*
* @throws IOException
* @throws IllegalAttributeException
* @throws NoSuchElementException
* @throws IllegalStateException DOCUMENT ME!
* @throws DataSourceException DOCUMENT ME!
*
* @see org.geotools.data.FeatureReader#next()
*/
public Object next()
throws NoSuchElementException {
if (reader == null) {
throw new IllegalStateException("Reader has already been closed");
}
//grab the next feature
SimpleFeature next = reader.next();
Object[] attributes = next.getAttributes().toArray();
try {
for (int i = 0; i < attributes.length; i++) {
if (attributes[i] instanceof Geometry) {
attributes[i] = transformer.transform((Geometry) attributes[i]);
}
}
} catch (TransformException e) {
throw (IllegalStateException)new IllegalStateException("A transformation exception occurred while reprojecting data on the fly").initCause(e);
}
return SimpleFeatureBuilder.build(schema, attributes, next.getID());
}
public void remove() {
throw new UnsupportedOperationException("On the fly reprojection disables remove");
}
/**
* Implement hasNext.
*
* <p>
* Description ...
* </p>
*
*
* @throws IOException
* @throws IllegalStateException DOCUMENT ME!
*
* @see org.geotools.data.FeatureReader#hasNext()
*/
public boolean hasNext(){
if (reader == null) {
throw new IllegalStateException("Reader has already been closed");
}
return reader.hasNext();
}
/**
* Implement close.
*
* <p>
* Description ...
* </p>
*
* @throws IOException
* @throws IllegalStateException DOCUMENT ME!
*
* @see org.geotools.data.FeatureReader#close()
*/
public void close() {
if (reader == null) {
return;
}
reader.close();
reader = null;
schema = null;
}
}