001 //$HeadURL: https://svn.wald.intevation.org/svn/deegree/base/branches/2.3_testing/src/org/deegree/ogcwebservices/csw/manager/ServiceHarvester.java $
002 /*----------------------------------------------------------------------------
003 This file is part of deegree, http://deegree.org/
004 Copyright (C) 2001-2009 by:
005 Department of Geography, University of Bonn
006 and
007 lat/lon GmbH
008
009 This library is free software; you can redistribute it and/or modify it under
010 the terms of the GNU Lesser General Public License as published by the Free
011 Software Foundation; either version 2.1 of the License, or (at your option)
012 any later version.
013 This library is distributed in the hope that it will be useful, but WITHOUT
014 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
015 FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
016 details.
017 You should have received a copy of the GNU Lesser General Public License
018 along with this library; if not, write to the Free Software Foundation, Inc.,
019 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
020
021 Contact information:
022
023 lat/lon GmbH
024 Aennchenstr. 19, 53177 Bonn
025 Germany
026 http://lat-lon.de/
027
028 Department of Geography, University of Bonn
029 Prof. Dr. Klaus Greve
030 Postfach 1147, 53001 Bonn
031 Germany
032 http://www.geographie.uni-bonn.de/deegree/
033
034 e-mail: info@deegree.org
035 ----------------------------------------------------------------------------*/
036 package org.deegree.ogcwebservices.csw.manager;
037
038 import java.io.IOException;
039 import java.net.URI;
040 import java.net.URL;
041 import java.util.Date;
042 import java.util.Iterator;
043 import java.util.List;
044
045 import javax.xml.transform.TransformerException;
046
047 import org.deegree.framework.log.ILogger;
048 import org.deegree.framework.log.LoggerFactory;
049 import org.deegree.framework.xml.XMLFragment;
050 import org.deegree.framework.xml.XMLParsingException;
051 import org.deegree.framework.xml.XMLTools;
052 import org.deegree.framework.xml.XSLTDocument;
053 import org.deegree.ogcwebservices.csw.manager.HarvestRepository.ResourceType;
054 import org.xml.sax.SAXException;
055
056 /**
057 * <p>
058 * Concrete implementation of
059 *
060 * @see org.deegree.ogcwebservices.csw.manager.AbstractHarvester for harvesting service metadata
061 * from OGC web services. To enable this capabilities documents of the OWS will be accessed and
062 * transformed into a valid format that will be understood by the underlying catalogue. To
063 * enable a lot of flexibility a XSLT read from resource bundle (harvestservice.xsl) script
064 * will be used to perform the required transformation.
065 * </p>
066 * <p>
067 * A valid harvest SOURCE for a service must be a complete GetCapabilities request; the
068 * RESOURCETYPE must be 'service'. Example:
069 * </p>
070 * <p>
071 * ...?request=Harvest&version=2.0.0&source=[http://MyServer:8080/deegree?
072 * service=WFS&version=1.1.0&request=GetCapabilities]&resourceType=service&
073 * resourceFormat=text/xml&responseHandler=mailto:info@lat-lon.de&harvestInterval=P2W
074 * </p>
075 * <p>
076 * value in brackets [..] must be URL encoded and send without brackets!
077 * </p>
078 * <p>
079 * This is not absolutly compliant to OGc CSW 2.0.0 specification but Harvest definition as
080 * available from the spec is to limited because it just targets single metadata documents.
081 * </p>
082 *
083 * @version $Revision: 19475 $
084 * @author <a href="mailto:poth@lat-lon.de">Andreas Poth</a>
085 * @author last edited by: $Author: lbuesching $
086 *
087 * @version 1.0. $Revision: 19475 $, $Date: 2009-09-02 14:51:48 +0200 (Mi, 02. Sep 2009) $
088 *
089 * @since 2.0
090 */
091 public class ServiceHarvester extends AbstractHarvester {
092
093 static final ILogger LOG = LoggerFactory.getLogger( ServiceHarvester.class );
094
095 static final URL xslt = ServiceHarvester.class.getResource( "harvestservice.xsl" );
096
097 private static ServiceHarvester sh = null;
098
099 /**
100 * @param version
101 * the version of the CSW
102 */
103 public ServiceHarvester( String version ) {
104 super( version );
105 }
106
107 /**
108 * singelton
109 *
110 * @param version
111 * the version of the CSW
112 *
113 * @return the new instance
114 */
115 public static ServiceHarvester getInstance( String version ) {
116 if ( sh == null ) {
117 sh = new ServiceHarvester( version );
118 }
119 return sh;
120 }
121
122 @Override
123 public void run() {
124 LOG.logDebug( "starting harvest iteration for ServiceHarvester." );
125 try {
126 HarvestRepository repository = HarvestRepository.getInstance();
127
128 List<URI> sources = repository.getSources();
129 for ( Iterator<URI> iter = sources.iterator(); iter.hasNext(); ) {
130 URI source = iter.next();
131 try {
132 // determine if source shall be harvested
133 if ( shallHarvest( source, ResourceType.service ) ) {
134 inProgress.add( source );
135 HarvestProcessor processor = new HarvestProcessor( this, source );
136 processor.start();
137 }
138 } catch ( Exception e ) {
139 LOG.logError( "Exception harvesting service: " + source, e );
140 informResponseHandlers( source, e );
141 }
142 }
143 } catch ( Exception e ) {
144 LOG.logError( "generell Exception harvesting services", e );
145 }
146
147 }
148
149 /**
150 * inner class for processing asynchronous harvesting of a service
151 *
152 * @version $Revision: 19475 $
153 * @author <a href="mailto:poth@lat-lon.de">Andreas Poth</a>
154 * @author last edited by: $Author: lbuesching $
155 *
156 * @version 1.0. $Revision: 19475 $, $Date: 2009-09-02 14:51:48 +0200 (Mi, 02. Sep 2009) $
157 *
158 * @since 2.0
159 */
160 protected class HarvestProcessor extends AbstractHarvestProcessor {
161
162 HarvestProcessor( AbstractHarvester owner, URI source ) {
163 super( owner, source );
164 }
165
166 @Override
167 public void run() {
168 try {
169 HarvestRepository repository = HarvestRepository.getInstance();
170 XMLFragment capabilities = accessSourceCapabilities( source );
171 Date harvestingTimestamp = repository.getNextHarvestingTimestamp( source );
172 XMLFragment metaData = transformCapabilities( capabilities );
173 String trans = null;
174 if ( repository.getLastHarvestingTimestamp( source ) == null ) {
175 trans = createInsertRequest( metaData );
176 } else {
177 trans = createUpdateRequest( getID( metaData ), getIdentifierXPathForUpdate( metaData ), metaData );
178 }
179 performTransaction( trans );
180 // update timestamps just if transaction has been performed
181 // successfully
182 writeLastHarvestingTimestamp( source, harvestingTimestamp );
183 writeNextHarvestingTimestamp( source, harvestingTimestamp );
184 informResponseHandlers( source );
185 } catch ( Exception e ) {
186 LOG.logError( "could not perform harvest operation for source: " + source, e );
187 try {
188 owner.informResponseHandlers( source, e );
189 } catch ( Exception ee ) {
190 ee.printStackTrace();
191 }
192 }
193 }
194
195 private String getID( XMLFragment metaData )
196 throws XMLParsingException {
197 String xpath = getIdentifierXPath( metaData );
198 String fileIdentifier = XMLTools.getRequiredNodeAsString( metaData.getRootElement(), xpath, nsc );
199 return fileIdentifier;
200 }
201
202 @Override
203 protected String createConstraint( String fileIdentifier, String xPath ) {
204 throw new UnsupportedOperationException();
205 }
206
207 /**
208 * transforms a OWS capabilities document into the desired target format
209 *
210 * @param xml
211 * @return the transformed document
212 * @throws IOException
213 * @throws SAXException
214 * @throws TransformerException
215 */
216 private XMLFragment transformCapabilities( XMLFragment xml )
217 throws IOException, SAXException, TransformerException {
218
219 XSLTDocument xsltDoc = new XSLTDocument();
220 xsltDoc.load( xslt );
221
222 return xsltDoc.transform( xml );
223 }
224
225 /**
226 * returns the capabilities of
227 *
228 * @param source
229 * @return the capabilities
230 * @throws IOException
231 * @throws SAXException
232 */
233 private XMLFragment accessSourceCapabilities( URI source )
234 throws IOException, SAXException {
235
236 URL url = source.toURL();
237 XMLFragment xml = new XMLFragment();
238 xml.load( url );
239 return xml;
240 }
241
242 }
243
244 }