001 //$HeadURL: svn+ssh://rbezema@svn.wald.intevation.org/deegree/base/branches/2.2_testing/src/org/deegree/ogcwebservices/wfs/GetFeatureHandler.java $
002 /*---------------- FILE HEADER ------------------------------------------
003
004 This file is part of deegree.
005 Copyright (C) 2001-2008 by:
006 EXSE, Department of Geography, University of Bonn
007 http://www.giub.uni-bonn.de/deegree/
008 lat/lon GmbH
009 http://www.lat-lon.de
010
011 This library is free software; you can redistribute it and/or
012 modify it under the terms of the GNU Lesser General Public
013 License as published by the Free Software Foundation; either
014 version 2.1 of the License, or (at your option) any later version.
015
016 This library is distributed in the hope that it will be useful,
017 but WITHOUT ANY WARRANTY; without even the implied warranty of
018 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
019 Lesser General Public License for more details.
020
021 You should have received a copy of the GNU Lesser General Public
022 License along with this library; if not, write to the Free Software
023 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
024
025 Contact:
026
027 Andreas Poth
028 lat/lon GmbH
029 Aennchenstr. 19
030 53177 Bonn
031 Germany
032 E-Mail: poth@lat-lon.de
033
034 Prof. Dr. Klaus Greve
035 Department of Geography
036 University of Bonn
037 Meckenheimer Allee 166
038 53115 Bonn
039 Germany
040 E-Mail: greve@giub.uni-bonn.de
041
042 ---------------------------------------------------------------------------*/
043 package org.deegree.ogcwebservices.wfs;
044
045 import java.util.ArrayList;
046 import java.util.List;
047 import java.util.concurrent.Callable;
048 import java.util.concurrent.CancellationException;
049
050 import org.deegree.datatypes.QualifiedName;
051 import org.deegree.framework.concurrent.ExecutionFinishedEvent;
052 import org.deegree.framework.concurrent.Executor;
053 import org.deegree.framework.log.ILogger;
054 import org.deegree.framework.log.LoggerFactory;
055 import org.deegree.i18n.Messages;
056 import org.deegree.io.datastore.Datastore;
057 import org.deegree.io.datastore.schema.MappedFeatureType;
058 import org.deegree.model.feature.FeatureCollection;
059 import org.deegree.model.feature.GMLFeatureAdapter;
060 import org.deegree.model.feature.GMLFeatureCollectionDocument;
061 import org.deegree.ogcwebservices.OGCWebServiceException;
062 import org.deegree.ogcwebservices.wfs.capabilities.WFSCapabilities;
063 import org.deegree.ogcwebservices.wfs.capabilities.WFSFeatureType;
064 import org.deegree.ogcwebservices.wfs.capabilities.WFSOperationsMetadata;
065 import org.deegree.ogcwebservices.wfs.configuration.WFSConfiguration;
066 import org.deegree.ogcwebservices.wfs.operation.FeatureResult;
067 import org.deegree.ogcwebservices.wfs.operation.GetFeature;
068 import org.deegree.ogcwebservices.wfs.operation.Query;
069 import org.deegree.ogcwebservices.wfs.operation.GetFeature.RESULT_TYPE;
070 import org.deegree.owscommon.OWSDomainType;
071
072 /**
073 * Handles {@link GetFeature} requests to the {@link WFService}. Since a {@link GetFeature} request
074 * may contain more than one {@link Query}, each {@link Query} is delegated to an own thread.
075 * <p>
076 * The results of all threads are collected and merged before they are returned to the calling
077 * {@link WFService} as a single {@link FeatureCollection}.
078 *
079 * @author <a href="mailto:poth@lat-lon.de">Andreas Poth</a>
080 * @author <a href="mailto:schneider@lat-lon.de">Markus Schneider</a>
081 * @author last edited by: $Author: apoth $
082 *
083 * @version $Revision: 9345 $, $Date: 2007-12-27 17:22:25 +0100 (Do, 27 Dez 2007) $
084 */
085 class GetFeatureHandler {
086
087 private static final ILogger LOG = LoggerFactory.getLogger( GetFeatureHandler.class );
088
089 private static final String EPSG_URL = "http://www.opengis.net/gml/srs/epsg.xml#";
090
091 // upper limit for timeout (overrides WFS configuration)
092 private static long MAX_TIMEOUT_MILLIS = 60 * 60 * 1000;
093
094 private WFService wfs;
095
096 private int maxFeatures = -1;
097
098 /**
099 * Creates a new instance of <code>GetFeatureHandler</code>. Only called by the associated
100 * {@link WFService} (once).
101 *
102 * @param wfs
103 * associated WFService
104 */
105 GetFeatureHandler( WFService wfs ) {
106 this.wfs = wfs;
107 WFSCapabilities capa = wfs.getCapabilities();
108 WFSOperationsMetadata md = (WFSOperationsMetadata) capa.getOperationsMetadata();
109 OWSDomainType[] dt = md.getConstraints();
110 for ( int i = 0; i < dt.length; i++ ) {
111 if ( dt[i].getName().equals( "DefaultMaxFeatures" ) ) {
112 try {
113 String tmp = dt[i].getValues()[0];
114 this.maxFeatures = Integer.parseInt( tmp );
115 } catch ( Exception e ) {
116 // e.printStackTrace();
117 }
118 break;
119 }
120 }
121 LOG.logDebug( "default maxFeatures " + this.maxFeatures );
122 }
123
124 /**
125 * Handles a {@link GetFeature} request by delegating the contained {@link Query} objects to
126 * different threads.
127 * <p>
128 * If at least one query fails an exception will be thrown and all running threads will be
129 * stopped.
130 *
131 * @param getFeature
132 * @return result of the request
133 * @throws OGCWebServiceException
134 */
135 FeatureResult handleRequest( GetFeature getFeature )
136 throws OGCWebServiceException {
137
138 if ( getFeature.getMaxFeatures() > this.maxFeatures || getFeature.getMaxFeatures() <= 0 ) {
139 getFeature.setMaxFeatures( this.maxFeatures );
140 }
141
142 LOG.logDebug( "maxFeatures " + getFeature.getMaxFeatures() );
143
144 Query[] queries = getFeature.getQuery();
145 List<Callable<FeatureCollection>> queryTasks = new ArrayList<Callable<FeatureCollection>>( queries.length );
146
147 for ( Query query : queries ) {
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 // check and normalize requested SRS
182 // TODO what about joins here?
183 String srsName = query.getSrsName();
184 if ( srsName != null ) {
185 WFSFeatureType wfsFT = this.wfs.getCapabilities().getFeatureTypeList().getFeatureType( ftNames[0] );
186 String normalizedSrsName = normalizeSrsName( srsName );
187 query.setSrsName( normalizedSrsName );
188
189 if ( !( wfsFT.supportsSrs( normalizedSrsName ) ) ) {
190 String msg = Messages.getMessage( "WFS_FEATURE_TYPE_SRS_UNSUPPORTED", ftNames[0], srsName );
191 throw new OGCWebServiceException( this.getClass().getName(), msg );
192 }
193 }
194
195 QueryTask task = new QueryTask( ds, query, requestedFts );
196 queryTasks.add( task );
197 }
198
199 WFSConfiguration conf = (WFSConfiguration) wfs.getCapabilities();
200 long timeout = conf.getDeegreeParams().getRequestTimeLimit() * 1000;
201 if ( timeout > MAX_TIMEOUT_MILLIS ) {
202 // limit max timeout
203 timeout = MAX_TIMEOUT_MILLIS;
204 }
205
206 List<ExecutionFinishedEvent<FeatureCollection>> finishedEvents = null;
207 try {
208 finishedEvents = Executor.getInstance().performSynchronously( queryTasks, timeout );
209 } catch ( InterruptedException e ) {
210 String msg = "Exception occured while waiting for the GetFeature results: " + e.getMessage();
211 throw new OGCWebServiceException( this.getClass().getName(), msg );
212 }
213
214 // use id of the request as id of the result feature collection
215 // to allow identification of the original request that produced
216 // the feature collection
217 FeatureCollection fc = null;
218 if ( getFeature.getResultType() == RESULT_TYPE.RESULTS ) {
219 fc = mergeResults( getFeature.getId(), finishedEvents );
220 } else {
221 fc = mergeHits( getFeature.getId(), finishedEvents );
222 }
223
224 if ( LOG.getLevel() == ILogger.LOG_DEBUG ) {
225 try {
226 GMLFeatureAdapter ada = new GMLFeatureAdapter( false );
227 GMLFeatureCollectionDocument doc = ada.export( fc );
228 LOG.logDebugXMLFile( "GetFeatureHandler_result", doc );
229 } catch ( Exception e ) {
230 LOG.logError( e.getMessage(), e );
231 }
232 }
233
234 FeatureResult fr = new FeatureResult( getFeature, fc );
235 return fr;
236 }
237
238 /**
239 * Merges the results of the request subparts into one feature collection.
240 *
241 * @param fcid
242 * id of the new (result) feature collection
243 * @param finishedEvents
244 * @return feature collection containing all features from all responses
245 * @throws OGCWebServiceException
246 */
247 private FeatureCollection mergeResults( String fcid, List<ExecutionFinishedEvent<FeatureCollection>> finishedEvents )
248 throws OGCWebServiceException {
249
250 FeatureCollection result = null;
251
252 try {
253 for ( ExecutionFinishedEvent<FeatureCollection> event : finishedEvents ) {
254 if ( result == null ) {
255 result = event.getResult();
256 } else {
257 result.addAll( event.getResult() );
258 }
259 }
260 } catch ( CancellationException e ) {
261 LOG.logError( e.getMessage(), e );
262 String msg = Messages.getMessage( "WFS_GET_FEATURE_TIMEOUT", e.getMessage() );
263 throw new OGCWebServiceException( this.getClass().getName(), msg );
264 } catch ( Throwable t ) {
265 LOG.logError( t.getMessage(), t );
266 String msg = Messages.getMessage( "WFS_GET_FEATURE_BACKEND", t.getMessage() );
267 throw new OGCWebServiceException( this.getClass().getName(), msg );
268 }
269
270 result.setId( fcid );
271 result.setAttribute( "numberOfFeatures", "" + result.size() );
272 return result;
273 }
274
275 /**
276 * Merges the results of the request subparts into one feature collection.
277 * <p>
278 * This method is used if only the HITS have been requested, i.e. the number of features.
279 *
280 * TODO: Do this a better way (maybe change feature model).
281 *
282 * @param fcid
283 * id of the new (result) feature collection
284 * @param finishedEvents
285 * @return empty feature collection with "numberOfFeatures" attribute
286 * @throws OGCWebServiceException
287 */
288 private FeatureCollection mergeHits( String fcid, List<ExecutionFinishedEvent<FeatureCollection>> finishedEvents )
289 throws OGCWebServiceException {
290
291 FeatureCollection result = null;
292 int numberOfFeatures = 0;
293
294 try {
295 for ( ExecutionFinishedEvent<FeatureCollection> event : finishedEvents ) {
296 FeatureCollection fc = event.getResult();
297 try {
298 numberOfFeatures += Integer.parseInt( ( fc.getAttribute( "numberOfFeatures" ) ) );
299 } catch ( NumberFormatException e ) {
300 String msg = "Internal error. Could not parse 'numberOfFeatures' attribute "
301 + "of sub-result as an integer value.";
302 throw new OGCWebServiceException( this.getClass().getName(), msg );
303 }
304 if ( result == null ) {
305 result = fc;
306 } else {
307 result.addAll( fc );
308 }
309 }
310 } catch ( CancellationException e ) {
311 String msg = Messages.getMessage( "WFS_GET_FEATURE_TIMEOUT" );
312 LOG.logError( msg, e );
313 throw new OGCWebServiceException( this.getClass().getName(), msg );
314 } catch ( Throwable t ) {
315 String msg = Messages.getMessage( "WFS_GET_FEATURE_BACKEND", t.getMessage() );
316 LOG.logError( msg, t );
317 throw new OGCWebServiceException( this.getClass().getName(), msg );
318 }
319
320 result.setId( fcid );
321 result.setAttribute( "numberOfFeatures", "" + numberOfFeatures );
322 return result;
323 }
324
325 /**
326 * Returns a normalized version of the given srs identifier.
327 * <p>
328 * Names in the format: <code>http://www.opengis.net/gml/srs/epsg.xml#XYZ</code> are returned
329 * as <code>EPSG:XYZ</code>.
330 *
331 * @param srsName
332 * name of the srs, <code>EPSG:xyz</code>
333 * @return a normalized version of <code>srsName</code>
334 */
335 private String normalizeSrsName( String srsName ) {
336 String normalizedName = srsName;
337 if ( srsName.startsWith( EPSG_URL ) ) {
338 String epsgCode = srsName.substring( EPSG_URL.length() );
339 normalizedName = "EPSG:" + epsgCode;
340 }
341 return normalizedName;
342 }
343
344 // ///////////////////////////////////////////////////////////////////////////
345 // inner classes
346 // ///////////////////////////////////////////////////////////////////////////
347
348 /**
349 * Inner class for performing queries on a datastore.
350 */
351 private class QueryTask implements Callable<FeatureCollection> {
352
353 private Datastore ds;
354
355 private Query query;
356
357 private MappedFeatureType[] fts;
358
359 QueryTask( Datastore ds, Query query, MappedFeatureType[] fts ) {
360 this.ds = ds;
361 this.query = query;
362 this.fts = fts;
363 }
364
365 /**
366 * Performs the associated {@link Query} and returns the result.
367 *
368 * @return resulting feature collection
369 * @throws Exception
370 */
371 public FeatureCollection call()
372 throws Exception {
373 FeatureCollection result = this.ds.performQuery( query, fts );
374 return result;
375 }
376 }
377 }