    001    //$HeadURL: https://svn.wald.intevation.org/svn/deegree/base/branches/2.4_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    }