001    //$HeadURL: svn+ssh://jwilden@svn.wald.intevation.org/deegree/base/branches/2.5_testing/src/org/deegree/ogcwebservices/wfs/GetFeatureHandler.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.wfs;
037    
038    import static org.deegree.framework.util.TimeTools.getISOFormattedTime;
039    import static org.deegree.ogcbase.ExceptionCode.INVALIDPARAMETERVALUE;
040    
041    import java.util.ArrayList;
042    import java.util.List;
043    import java.util.concurrent.Callable;
044    import java.util.concurrent.CancellationException;
045    
046    import org.deegree.datatypes.QualifiedName;
047    import org.deegree.framework.concurrent.ExecutionFinishedEvent;
048    import org.deegree.framework.concurrent.Executor;
049    import org.deegree.framework.log.ILogger;
050    import org.deegree.framework.log.LoggerFactory;
051    import org.deegree.i18n.Messages;
052    import org.deegree.io.datastore.Datastore;
053    import org.deegree.io.datastore.PropertyPathResolvingException;
054    import org.deegree.io.datastore.schema.MappedFeatureType;
055    import org.deegree.model.feature.FeatureCollection;
056    import org.deegree.model.feature.GMLFeatureAdapter;
057    import org.deegree.model.feature.GMLFeatureCollectionDocument;
058    import org.deegree.ogcwebservices.OGCWebServiceException;
059    import org.deegree.ogcwebservices.wfs.capabilities.WFSCapabilities;
060    import org.deegree.ogcwebservices.wfs.capabilities.WFSFeatureType;
061    import org.deegree.ogcwebservices.wfs.capabilities.WFSOperationsMetadata;
062    import org.deegree.ogcwebservices.wfs.configuration.WFSConfiguration;
063    import org.deegree.ogcwebservices.wfs.operation.FeatureResult;
064    import org.deegree.ogcwebservices.wfs.operation.GetFeature;
065    import org.deegree.ogcwebservices.wfs.operation.Query;
066    import org.deegree.ogcwebservices.wfs.operation.GetFeature.RESULT_TYPE;
067    import org.deegree.owscommon.OWSDomainType;
068    
069    /**
070     * Handles {@link GetFeature} requests to the {@link WFService}. Since a {@link GetFeature} request may contain more
071     * than one {@link Query}, each {@link Query} is delegated to an own thread.
072     * <p>
073     * The results of all threads are collected and merged before they are returned to the calling {@link WFService} as a
074     * single {@link FeatureCollection}.
075     *
076     * @author <a href="mailto:poth@lat-lon.de">Andreas Poth</a>
077     * @author <a href="mailto:schneider@lat-lon.de">Markus Schneider</a>
078     * @author last edited by: $Author: mschneider $
079     *
080     * @version $Revision: 18195 $, $Date: 2009-06-18 17:55:39 +0200 (Do, 18 Jun 2009) $
081     */
082    class GetFeatureHandler {
083    
084        private static final ILogger LOG = LoggerFactory.getLogger( GetFeatureHandler.class );
085    
086        // upper limit for timeout (overrides WFS configuration)
087        private static long MAX_TIMEOUT_MILLIS = 60 * 60 * 1000;
088    
089        private WFService wfs;
090    
091        private int maxFeatures = -1;
092    
093        /**
094         * Creates a new instance of <code>GetFeatureHandler</code>. Only called by the associated {@link WFService} (once).
095         *
096         * @param wfs
097         *            associated WFService
098         */
099        GetFeatureHandler( WFService wfs ) {
100            this.wfs = wfs;
101            WFSCapabilities capa = wfs.getCapabilities();
102            WFSOperationsMetadata md = (WFSOperationsMetadata) capa.getOperationsMetadata();
103            OWSDomainType[] dt = md.getConstraints();
104            for ( int i = 0; i < dt.length; i++ ) {
105                if ( dt[i].getName().equals( "DefaultMaxFeatures" ) ) {
106                    try {
107                        String tmp = dt[i].getValues()[0];
108                        this.maxFeatures = Integer.parseInt( tmp );
109                    } catch ( Exception e ) {
110                        // e.printStackTrace();
111                    }
112                    break;
113                }
114            }
115            LOG.logDebug( "default maxFeatures " + this.maxFeatures );
116        }
117    
118        /**
119         * Handles a {@link GetFeature} request by delegating the contained {@link Query} objects to different threads.
120         * <p>
121         * If at least one query fails an exception will be thrown and all running threads will be stopped.
122         *
123         * @param getFeature
124         * @return result of the request
125         * @throws OGCWebServiceException
126         */
127        FeatureResult handleRequest( GetFeature getFeature )
128                                throws OGCWebServiceException {
129    
130            WFSConfiguration conf = (WFSConfiguration) wfs.getCapabilities();
131    
132            if ( getFeature.getMaxFeatures() > this.maxFeatures || getFeature.getMaxFeatures() <= 0 ) {
133                getFeature.setMaxFeatures( this.maxFeatures );
134            }
135    
136            LOG.logDebug( "maxFeatures " + getFeature.getMaxFeatures() );
137    
138            Query[] queries = getFeature.getQuery();
139            List<Callable<FeatureCollection>> queryTasks = new ArrayList<Callable<FeatureCollection>>( queries.length );
140    
141            for ( Query query : queries ) {
142    
143                if ( conf.getDeegreeParams().checkUTMZones() ) {
144                    query.performBBoxTest();
145                }
146    
147                query.deleteBBoxTest();
148    
149                QualifiedName[] ftNames = query.getTypeNames();
150                MappedFeatureType[] requestedFts = new MappedFeatureType[ftNames.length];
151                Datastore ds = null;
152    
153                for ( int i = 0; i < ftNames.length; i++ ) {
154                    QualifiedName ftName = ftNames[i];
155                    MappedFeatureType ft = this.wfs.getMappedFeatureType( ftName );
156    
157                    if ( ft == null ) {
158                        String msg = Messages.getMessage( "WFS_FEATURE_TYPE_UNKNOWN", ftName );
159                        throw new OGCWebServiceException( this.getClass().getName(), msg );
160                    }
161                    if ( ft.isAbstract() ) {
162                        String msg = Messages.getMessage( "WFS_FEATURE_TYPE_ABSTRACT", ftName );
163                        throw new OGCWebServiceException( this.getClass().getName(), msg );
164                    }
165                    if ( !ft.isVisible() ) {
166                        String msg = Messages.getMessage( "WFS_FEATURE_TYPE_INVISIBLE", ftName );
167                        throw new OGCWebServiceException( this.getClass().getName(), msg );
168                    }
169                    Datastore dsForFt = ft.getGMLSchema().getDatastore();
170                    if ( ds != null ) {
171                        if ( ds != dsForFt ) {
172                            String msg = Messages.getMessage( "WFS_QUERY_JOIN_OVER_DIFFERENT_DS" );
173                            throw new OGCWebServiceException( this.getClass().getName(), msg );
174                        }
175                    } else {
176                        ds = dsForFt;
177                    }
178                    requestedFts[i] = ft;
179                }
180    
181                // TODO what about joins here?
182                String srsName = query.getSrsName();
183                if ( srsName != null ) {
184                    WFSFeatureType wfsFT = this.wfs.getCapabilities().getFeatureTypeList().getFeatureType( ftNames[0] );
185    
186                    if ( !( wfsFT.supportsSrs( srsName ) ) ) {
187                        String msg = Messages.getMessage( "WFS_FEATURE_TYPE_SRS_UNSUPPORTED", ftNames[0], srsName );
188                        throw new OGCWebServiceException( this.getClass().getName(), msg );
189                    }
190                }
191    
192                QueryTask task = new QueryTask( ds, query, requestedFts );
193                queryTasks.add( task );
194            }
195    
196            long timeout = conf.getDeegreeParams().getRequestTimeLimit() * 1000;
197            if ( timeout > MAX_TIMEOUT_MILLIS ) {
198                // limit max timeout
199                timeout = MAX_TIMEOUT_MILLIS;
200            }
201    
202            List<ExecutionFinishedEvent<FeatureCollection>> finishedEvents = null;
203            try {
204                finishedEvents = Executor.getInstance().performSynchronously( queryTasks, timeout );
205            } catch ( InterruptedException e ) {
206                String msg = "Exception occured while waiting for the GetFeature results: " + e.getMessage();
207                throw new OGCWebServiceException( this.getClass().getName(), msg );
208            }
209    
210            // use id of the request as id of the result feature collection
211            // to allow identification of the original request that produced
212            // the feature collection
213            FeatureCollection fc = null;
214            if ( getFeature.getResultType() == RESULT_TYPE.RESULTS ) {
215                fc = mergeResults( getFeature.getId(), finishedEvents );
216            } else {
217                fc = mergeHits( getFeature.getId(), finishedEvents );
218            }
219    
220            // TODO this is not a good solution
221            // I think it can happen if more than one feature type is requested
222            while ( getFeature.getMaxFeatures() > 0 && fc.size() > getFeature.getMaxFeatures() ) {
223                fc.remove( fc.size() - 1 );
224            }
225    
226            if ( LOG.isDebug() ) {
227                try {
228                    GMLFeatureAdapter ada = new GMLFeatureAdapter( false );
229                    GMLFeatureCollectionDocument doc = ada.export( fc );
230                    LOG.logDebugXMLFile( "GetFeatureHandler_result", doc );
231                } catch ( Exception e ) {
232                    LOG.logError( e.getMessage(), e );
233                }
234            }
235    
236            FeatureResult fr = new FeatureResult( getFeature, fc );
237            return fr;
238        }
239    
240        /**
241         * Merges the results of the request subparts into one feature collection.
242         *
243         * @param fcid
244         *            id of the new (result) feature collection
245         * @param finishedEvents
246         * @return feature collection containing all features from all responses
247         * @throws OGCWebServiceException
248         */
249        private FeatureCollection mergeResults( String fcid, List<ExecutionFinishedEvent<FeatureCollection>> finishedEvents )
250                                throws OGCWebServiceException {
251    
252            FeatureCollection result = null;
253    
254            try {
255                for ( ExecutionFinishedEvent<FeatureCollection> event : finishedEvents ) {
256                    if ( result == null ) {
257                        result = event.getResult();
258                    } else {
259                        result.addAllUncontained( event.getResult() );
260                    }
261                }
262    
263                if ( result == null ) {
264                    return result;
265                }
266            } catch ( CancellationException e ) {
267                LOG.logError( e.getMessage(), e );
268                String msg = Messages.getMessage( "WFS_GET_FEATURE_TIMEOUT", e.getMessage() );
269                throw new OGCWebServiceException( this.getClass().getName(), msg );
270            } catch ( PropertyPathResolvingException e ) {
271                LOG.logDebug( "Stack trace", e );
272                throw new OGCWebServiceException( e.getLocalizedMessage(), INVALIDPARAMETERVALUE );
273            } catch ( Throwable t ) {
274                LOG.logError( t.getMessage(), t );
275                String msg = Messages.getMessage( "WFS_GET_FEATURE_BACKEND", t.getMessage() );
276                throw new OGCWebServiceException( this.getClass().getName(), msg );
277            }
278    
279            result.setId( fcid );
280            result.setAttribute( "numberOfFeatures", "" + result.size() );
281            return result;
282        }
283    
284        /**
285         * Merges the results of the request subparts into one feature collection.
286         * <p>
287         * This method is used if only the HITS have been requested, i.e. the number of features.
288         *
289         * TODO: Do this a better way (maybe change feature model).
290         *
291         * @param fcid
292         *            id of the new (result) feature collection
293         * @param finishedEvents
294         * @return empty feature collection with "numberOfFeatures" attribute
295         * @throws OGCWebServiceException
296         */
297        private FeatureCollection mergeHits( String fcid, List<ExecutionFinishedEvent<FeatureCollection>> finishedEvents )
298                                throws OGCWebServiceException {
299    
300            FeatureCollection result = null;
301            int numberOfFeatures = 0;
302    
303            try {
304                for ( ExecutionFinishedEvent<FeatureCollection> event : finishedEvents ) {
305                    FeatureCollection fc = event.getResult();
306                    try {
307                        numberOfFeatures += Integer.parseInt( ( fc.getAttribute( "numberOfFeatures" ) ) );
308                    } catch ( NumberFormatException e ) {
309                        String msg = "Internal error. Could not parse 'numberOfFeatures' attribute "
310                                     + "of sub-result as an integer value.";
311                        throw new OGCWebServiceException( this.getClass().getName(), msg );
312                    }
313                    if ( result == null ) {
314                        result = fc;
315                    } else {
316                        result.addAllUncontained( fc );
317                    }
318                }
319    
320                if ( result == null ) {
321                    return result;
322                }
323            } catch ( CancellationException e ) {
324                String msg = Messages.getMessage( "WFS_GET_FEATURE_TIMEOUT" );
325                LOG.logError( msg, e );
326                throw new OGCWebServiceException( this.getClass().getName(), msg );
327            } catch ( Throwable t ) {
328                String msg = Messages.getMessage( "WFS_GET_FEATURE_BACKEND", t.getMessage() );
329                LOG.logError( msg, t );
330                throw new OGCWebServiceException( this.getClass().getName(), msg );
331            }
332    
333            result.setId( fcid );
334            result.setAttribute( "numberOfFeatures", "" + numberOfFeatures );
335            result.setAttribute( "timeStamp", getISOFormattedTime() );
336            return result;
337        }
338    
339        // ///////////////////////////////////////////////////////////////////////////
340        // inner classes
341        // ///////////////////////////////////////////////////////////////////////////
342    
343        /**
344         * Inner class for performing queries on a datastore.
345         */
346        private class QueryTask implements Callable<FeatureCollection> {
347    
348            private Datastore ds;
349    
350            private Query query;
351    
352            private MappedFeatureType[] fts;
353    
354            QueryTask( Datastore ds, Query query, MappedFeatureType[] fts ) {
355                this.ds = ds;
356                this.query = query;
357                this.fts = fts;
358            }
359    
360            /**
361             * Performs the associated {@link Query} and returns the result.
362             *
363             * @return resulting feature collection
364             * @throws Exception
365             */
366            public FeatureCollection call()
367                                    throws Exception {
368                FeatureCollection result = this.ds.performQuery( query, fts );
369                return result;
370            }
371        }
372    }