/*---------------- FILE HEADER ------------------------------------------
This file is part of deegree.
Copyright (C) 2001-2006 by:
EXSE, Department of Geography, University of Bonn
http://www.giub.uni-bonn.de/deegree/
lat/lon GmbH
http://www.lat-lon.de
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; either
version 2.1 of the License, or (at your option) any later version.
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.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Contact:
Andreas Poth
lat/lon GmbH
Aennchenstr. 19
53115 Bonn
Germany
E-Mail: poth@lat-lon.de
Prof. Dr. Klaus Greve
Department of Geography
University of Bonn
Meckenheimer Allee 166
53115 Bonn
Germany
E-Mail: greve@giub.uni-bonn.de
---------------------------------------------------------------------------*/
package org.deegree.ogcwebservices.csw.manager;
import java.io.IOException;
import java.net.URI;
import java.net.URL;
import java.util.Date;
import java.util.Iterator;
import java.util.List;
import javax.xml.transform.TransformerException;
import org.deegree.framework.log.ILogger;
import org.deegree.framework.log.LoggerFactory;
import org.deegree.framework.xml.XMLFragment;
import org.deegree.framework.xml.XMLParsingException;
import org.deegree.framework.xml.XMLTools;
import org.deegree.framework.xml.XSLTDocument;
import org.deegree.ogcwebservices.csw.manager.HarvestRepository.ResourceType;
import org.xml.sax.SAXException;
/**
* <p>
* Concrete implementation of
*
* @see org.deegree.ogcwebservices.csw.manager.AbstractHarvester for harvesting service metadata
* from OGC web services. To enable this capabilities documents of the OWS will be accessed and
* transformed into a valid format that will be understood by the underlying catalogue. To
* enable a lot of flexibility a XSLT read from resource bundle (harvestservice.xsl) script
* will be used to perform the required transformation.
* </p>
* <p>
* A valid harvest SOURCE for a service must be a complete GetCapabilities request; the
* RESOURCETYPE must be 'service'. Example:
* </p>
* <p>
* ...?request=Harvest&version=2.0.0&source=[http://MyServer:8080/deegree?
* service=WFS&version=1.1.0&request=GetCapabilities]&resourceType=service&
* resourceFormat=text/xml&responseHandler=mailto:info@lat-lon.de&harvestInterval=P2W
* </p>
* <p>
* value in brackets [..] must be URL encoded and send without brackets!
* </p>
* <p>
* This is not absolutly compliant to OGc CSW 2.0.0 specification but Harvest definition as
* available from the spec is to limited because it just targets single metadata documents.
* </p>
*
* @version $Revision: 1.13 $
* @author <a href="mailto:poth@lat-lon.de">Andreas Poth</a>
* @author last edited by: $Author: poth $
*
* @version 1.0. $Revision: 1.13 $, $Date: 2006/07/12 14:46:17 $
*
* @since 2.0
*/
public class ServiceHarvester extends AbstractHarvester {
private static final ILogger LOG = LoggerFactory.getLogger( ServiceHarvester.class );
private static final URL xslt = ServiceHarvester.class.getResource( "harvestservice.xsl" );
private static ServiceHarvester sh = null;
/**
* singelton
*
* @return
*/
public static ServiceHarvester getInstance() {
if ( sh == null ) {
sh = new ServiceHarvester();
}
return sh;
}
@Override
public void run() {
LOG.logDebug( "starting harvest iteration for ServiceHarvester." );
try {
HarvestRepository repository = HarvestRepository.getInstance();
List<URI> sources = repository.getSources();
for ( Iterator iter = sources.iterator(); iter.hasNext(); ) {
URI source = (URI) iter.next();
try {
// determine if source shall be harvested
if ( shallHarvest( source, ResourceType.service ) ) {
inProgress.add( source );
HarvestProcessor processor = new HarvestProcessor( this, source );
processor.start();
}
} catch ( Exception e ) {
LOG.logError( "Exception harvesting service: " + source, e );
informResponseHandlers( source, e );
}
}
} catch ( Exception e ) {
LOG.logError( "generell Exception harvesting services", e );
}
}
/**
* inner class for processing asynchronous harvesting of a service
*
* @version $Revision: 1.13 $
* @author <a href="mailto:poth@lat-lon.de">Andreas Poth</a>
* @author last edited by: $Author: poth $
*
* @version 1.0. $Revision: 1.13 $, $Date: 2006/07/12 14:46:17 $
*
* @since 2.0
*/
protected class HarvestProcessor extends AbstractHarvestProcessor {
HarvestProcessor( AbstractHarvester owner, URI source ) {
super( owner, source );
}
@Override
public void run() {
try {
HarvestRepository repository = HarvestRepository.getInstance();
XMLFragment capabilities = accessSourceCapabilities( source );
Date harvestingTimestamp = repository.getNextHarvestingTimestamp( source );
XMLFragment metaData = transformCapabilities( capabilities );
String trans = null;
if ( repository.getLastHarvestingTimestamp( source ) == null ) {
trans = createInsertRequest( metaData );
} else {
trans = createUpdateRequest( getID( metaData ),
"smXML:fileIdentifier/smXML:CharacterString",
metaData );
}
performTransaction( trans );
// update timestamps just if transaction has been performed
// successfully
writeLastHarvestingTimestamp( source, harvestingTimestamp );
writeNextHarvestingTimestamp( source, harvestingTimestamp );
informResponseHandlers( source );
} catch ( Exception e ) {
LOG.logError( "could not perform harvest operation for source: " + source, e );
try {
owner.informResponseHandlers( source, e );
} catch ( Exception ee ) {
ee.printStackTrace();
}
}
}
private String getID( XMLFragment metaData )
throws XMLParsingException {
String xpath = "smXML:fileIdentifier/smXML:CharacterString";
String fileIdentifier = XMLTools.getRequiredNodeAsString( metaData.getRootElement(),
xpath, nsc );
return fileIdentifier;
}
@Override
protected StringBuffer createConstraint( String fileIdentifier, String xPath ) {
// TODO Auto-generated method stub
return null;
}
/**
* transforms a OWS capabilities document into the desired target format
*
* @param xml
* @return
* @throws IOException
* @throws SAXException
* @throws TransformerException
*/
private XMLFragment transformCapabilities( XMLFragment xml )
throws IOException, SAXException, TransformerException {
XSLTDocument xsltDoc = new XSLTDocument();
xsltDoc.load( xslt );
return xsltDoc.transform( xml );
}
/**
* returns the capabilities of
*
* @param source
* @return
* @throws IOException
* @throws SAXException
*/
private XMLFragment accessSourceCapabilities( URI source )
throws IOException, SAXException {
URL url = source.toURL();
XMLFragment xml = new XMLFragment();
xml.load( url );
return xml;
}
}
}
/* ********************************************************************
Changes to this class. What the people have been up to:
$Log: ServiceHarvester.java,v $
Revision 1.13 2006/07/12 14:46:17 poth
comment footer added
********************************************************************** */