org.locationtech.jts.io.gml2.GMLReader Maven / Gradle / Ivy
/*
* Copyright (c) 2016 Vivid Solutions.
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* and Eclipse Distribution License v. 1.0 which accompanies this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
*
* http://www.eclipse.org/org/documents/edl-v10.php.
*/
package org.locationtech.jts.io.gml2;
import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.locationtech.jts.geom.Geometry;
import org.locationtech.jts.geom.GeometryCollection;
import org.locationtech.jts.geom.GeometryFactory;
import org.locationtech.jts.geom.PrecisionModel;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
/**
* Reads a GML2 geometry from an XML fragment into a {@link Geometry}.
*
* An example of the GML2 format handled is:
*
* <LineString>
* <coordinates>
* 24824.045318333192,38536.15071012041
* 26157.378651666528,37567.42733944659 26666.666,36000.0
* 26157.378651666528,34432.57266055341
* 24824.045318333192,33463.84928987959
* 23175.954681666804,33463.84928987959
* 21842.621348333472,34432.57266055341 21333.333,36000.0
* 21842.621348333472,37567.42733944659
* 23175.954681666808,38536.15071012041
* </coordinates>
* </LineString>
*
*
* The reader ignores namespace prefixes,
* and disables both the validation and namespace options on the SAXParser.
* This class requires the presence of a SAX Parser available via the
* {@link javax.xml.parsers.SAXParserFactory#newInstance()}
* method.
*
* A specification of the GML XML format
* can be found at the OGC web site: http://www.opengeospatial.org/.
*
* It is the caller's responsibility to ensure that the supplied {@link PrecisionModel}
* matches the precision of the incoming data.
* If a lower precision for the data is required, a subsequent
* process must be run on the data to reduce its precision.
*
* To parse and build geometry directly from a SAX stream, see {@link GMLHandler}.
*
* @author David Zwiers, Vivid Solutions.
*
* @see GMLHandler
*/
public class GMLReader
{
/**
* Reads a GML2 Geometry from a String into a single {@link Geometry}
*
* If a collection of geometries is found, a {@link GeometryCollection} is returned.
*
* @param gml The GML String to parse
* @param geometryFactory When null, a default will be used.
* @return the resulting JTS Geometry
*
* @throws ParserConfigurationException
* @throws IOException
* @throws SAXException
*
* @see #read(Reader, GeometryFactory)
*/
public Geometry read(String gml, GeometryFactory geometryFactory) throws SAXException, IOException, ParserConfigurationException{
return read(new StringReader(gml),geometryFactory);
}
/**
* Reads a GML2 Geometry from a {@link Reader} into a single {@link Geometry}
*
* If a collection of Geometries is found, a {@link GeometryCollection} is returned.
*
* @param reader The input source
* @param geometryFactory When null, a default will be used.
* @return The resulting JTS Geometry
* @throws SAXException
* @throws IOException
*/
public Geometry read(Reader reader, GeometryFactory geometryFactory) throws SAXException, IOException, ParserConfigurationException{
SAXParserFactory fact = SAXParserFactory.newInstance();
fact.setNamespaceAware(false);
fact.setValidating(false);
SAXParser parser = fact.newSAXParser();
if(geometryFactory == null)
geometryFactory = new GeometryFactory();
GMLHandler gh = new GMLHandler(geometryFactory,null);
parser.parse(new InputSource(reader), (DefaultHandler)gh);
return gh.getGeometry();
}
}