001    //$HeadURL: https://svn.wald.intevation.org/svn/deegree/base/branches/2.3_testing/src/org/deegree/io/datastore/idgenerator/FeatureIdAssigner.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.io.datastore.idgenerator;
037    
038    import java.util.ArrayList;
039    import java.util.Date;
040    import java.util.HashMap;
041    import java.util.HashSet;
042    import java.util.List;
043    import java.util.Map;
044    import java.util.Set;
045    
046    import org.deegree.datatypes.QualifiedName;
047    import org.deegree.framework.log.ILogger;
048    import org.deegree.framework.log.LoggerFactory;
049    import org.deegree.framework.util.TimeTools;
050    import org.deegree.io.datastore.Datastore;
051    import org.deegree.io.datastore.DatastoreException;
052    import org.deegree.io.datastore.DatastoreTransaction;
053    import org.deegree.io.datastore.FeatureId;
054    import org.deegree.io.datastore.schema.MappedFeatureType;
055    import org.deegree.io.datastore.schema.MappedGMLId;
056    import org.deegree.io.datastore.schema.MappedPropertyType;
057    import org.deegree.io.datastore.schema.MappedSimplePropertyType;
058    import org.deegree.io.datastore.schema.content.MappingField;
059    import org.deegree.io.datastore.schema.content.SimpleContent;
060    import org.deegree.model.crs.UnknownCRSException;
061    import org.deegree.model.feature.Feature;
062    import org.deegree.model.feature.FeatureCollection;
063    import org.deegree.model.feature.FeatureProperty;
064    import org.deegree.model.filterencoding.ComplexFilter;
065    import org.deegree.model.filterencoding.FeatureFilter;
066    import org.deegree.model.filterencoding.Filter;
067    import org.deegree.model.filterencoding.Literal;
068    import org.deegree.model.filterencoding.LogicalOperation;
069    import org.deegree.model.filterencoding.Operation;
070    import org.deegree.model.filterencoding.OperationDefines;
071    import org.deegree.model.filterencoding.PropertyIsCOMPOperation;
072    import org.deegree.model.filterencoding.PropertyName;
073    import org.deegree.model.spatialschema.Geometry;
074    import org.deegree.ogcbase.CommonNamespaces;
075    import org.deegree.ogcbase.PropertyPath;
076    import org.deegree.ogcbase.PropertyPathFactory;
077    import org.deegree.ogcwebservices.wfs.operation.GetFeature;
078    import org.deegree.ogcwebservices.wfs.operation.Query;
079    import org.deegree.ogcwebservices.wfs.operation.transaction.Insert;
080    import org.deegree.ogcwebservices.wfs.operation.transaction.Insert.ID_GEN;
081    
082    /**
083     * Responsible for the assigning of valid {@link FeatureId}s which are a prerequisite to the insertion of features in a
084     * {@link Datastore}. For each {@link Insert} operation, a new <code>FeatureIdAssigner</code> instance is created.
085     * <p>
086     * The behaviour of {@link #assignFID(Feature, DatastoreTransaction)}} depends on the {@link ID_GEN} mode in use:
087     * <table>
088     * <tr>
089     * <td>GenerateNew</td>
090     * <td>Prior to the assigning of new feature ids, "equal" features are looked up in the datastore and their feature ids
091     * are used.</td>
092     * </tr>
093     * <tr>
094     * <td>UseExisting</td>
095     * <td>
096     * <ol>
097     * <li>For every root feature, it is checked that a feature id is present and that no feature with the same id already
098     * exists in the datastore.</li>
099     * <li>"Equal" subfeatures are looked up in the datastore and their feature ids are used instead of the given fids --
100     * if however an "equal" root feature is identified, an exception is thrown.</li>
101     * </ol>
102     * </td>
103     * </tr>
104     * <tr>
105     * <td>ReplaceDuplicate</td>
106     * <td>not supported yet</td>
107     * </tr>
108     * </table>
109     *
110     * @see DatastoreTransaction#performInsert(List)
111     *
112     * @author <a href="mailto:schneider@lat-lon.de">Markus Schneider </a>
113     * @author last edited by: $Author: mschneider $
114     *
115     * @version $Revision: 18195 $, $Date: 2009-06-18 17:55:39 +0200 (Do, 18. Jun 2009) $
116     */
117    public class FeatureIdAssigner {
118    
119        /** if an assigned feature id starts with this, it is already stored */
120        public static final String EXISTS_MARKER = "!";
121    
122        private static final ILogger LOG = LoggerFactory.getLogger( FeatureIdAssigner.class );
123    
124        private ID_GEN idGenMode;
125    
126        private Map<String, FeatureId> oldFid2NewFidMap = new HashMap<String, FeatureId>();
127    
128        private Set<Feature> reassignedFeatures = new HashSet<Feature>();
129    
130        private Set<Feature> storedFeatures = new HashSet<Feature>();
131    
132        /**
133         * Creates a new <code>FeatureIdAssigner</code> instance that generates new feature ids as specified.
134         *
135         * @param idGenMode
136         */
137        public FeatureIdAssigner( ID_GEN idGenMode ) {
138            this.idGenMode = idGenMode;
139        }
140    
141        /**
142         * Assigns valid {@link FeatureId}s to the given feature instance and it's subfeatures.
143         *
144         * @param feature
145         * @param ta
146         * @throws IdGenerationException
147         */
148        public void assignFID( Feature feature, DatastoreTransaction ta )
149                                throws IdGenerationException {
150    
151            switch ( this.idGenMode ) {
152            case GENERATE_NEW: {
153                identifyStoredFeatures( feature, ta, new HashSet<Feature>() );
154                generateAndAssignNewFIDs( feature, null, ta );
155                break;
156            }
157            case REPLACE_DUPLICATE: {
158                LOG.logInfo( "Idgen mode 'ReplaceDuplicate' is not implemented!" );
159                break;
160            }
161            case USE_EXISTING: {
162                checkForExistingFid( feature, ta );
163                String oldFid = feature.getId();
164                String equalFeature = identifyStoredFeatures( feature, ta, new HashSet<Feature>() );
165                if ( equalFeature != null ) {
166                    String msg = "Cannot perform insert: a feature equal to a feature to be inserted (fid: '" + oldFid
167                                 + "') already exists in the datastore (existing fid: '" + equalFeature + "').";
168                    throw new IdGenerationException( msg );
169                }
170                break;
171            }
172            default: {
173                throw new IdGenerationException( "Internal error: Unhandled fid generation mode: " + this.idGenMode );
174            }
175            }
176        }
177    
178        /**
179         * TODO mark stored features a better way
180         */
181        public void markStoredFeatures() {
182            // hack: mark stored features (with "!")
183            for ( Feature f : this.storedFeatures ) {
184                String fid = f.getId();
185                if ( !fid.startsWith( EXISTS_MARKER ) ) {
186                    f.setId( EXISTS_MARKER + fid );
187                }
188            }
189        }
190    
191        private String identifyStoredFeatures( Feature feature, DatastoreTransaction ta, Set<Feature> inProcessing )
192                                throws IdGenerationException {
193    
194            if ( this.reassignedFeatures.contains( feature ) ) {
195                return feature.getId();
196            }
197    
198            inProcessing.add( feature );
199    
200            boolean maybeEqual = true;
201            String existingFID = null;
202    
203            LOG.logDebug( "Checking for existing feature that equals feature with type: '" + feature.getName()
204                          + "' and fid: '" + feature.getId() + "'." );
205    
206            // build the comparison operations that are needed to select "equal" feature instances
207            List<Operation> compOperations = new ArrayList<Operation>();
208    
209            FeatureProperty[] properties = feature.getProperties();
210            MappedFeatureType ft = (MappedFeatureType) feature.getFeatureType();
211    
212            for ( int i = 0; i < properties.length; i++ ) {
213                QualifiedName propertyName = properties[i].getName();
214                MappedPropertyType propertyType = (MappedPropertyType) ft.getProperty( propertyName );
215    
216                Object propertyValue = properties[i].getValue();
217                if ( propertyValue instanceof Feature ) {
218    
219                    if ( inProcessing.contains( propertyValue ) ) {
220                        LOG.logDebug( "Stopping recursion at property with '" + propertyName + "'. Cycle detected." );
221                        continue;
222                    }
223    
224                    LOG.logDebug( "Recursing on feature property: " + properties[i].getName() );
225                    String subFeatureId = identifyStoredFeatures( (Feature) propertyValue, ta, inProcessing );
226                    if ( propertyType.isIdentityPart() ) {
227                        if ( subFeatureId == null ) {
228                            maybeEqual = false;
229                        } else {
230                            LOG.logDebug( "Need to check for feature property '" + propertyName + "' with fid '"
231                                          + subFeatureId + "'." );
232    
233                            // build path that selects subfeature 'gml:id' attribute
234                            PropertyPath fidSelectPath = PropertyPathFactory.createPropertyPath( feature.getName() );
235                            fidSelectPath.append( PropertyPathFactory.createPropertyPathStep( propertyName ) );
236                            fidSelectPath.append( PropertyPathFactory.createPropertyPathStep( ( (Feature) propertyValue ).getName() ) );
237                            QualifiedName qn = new QualifiedName( CommonNamespaces.GML_PREFIX, "id", CommonNamespaces.GMLNS );
238                            fidSelectPath.append( PropertyPathFactory.createAttributePropertyPathStep( qn ) );
239    
240                            // hack that remove's the gml id prefix
241                            MappedFeatureType subFeatureType = (MappedFeatureType) ( (Feature) propertyValue ).getFeatureType();
242                            MappedGMLId gmlId = subFeatureType.getGMLId();
243                            String prefix = gmlId.getPrefix();
244                            if ( subFeatureId.indexOf( prefix ) != 0 ) {
245                                throw new IdGenerationException( "Internal error: subfeature id '" + subFeatureId
246                                                                 + "' does not begin with the expected prefix." );
247                            }
248                            String plainIdValue = subFeatureId.substring( prefix.length() );
249                            PropertyIsCOMPOperation propertyTestOperation = new PropertyIsCOMPOperation(
250                                                                                                         OperationDefines.PROPERTYISEQUALTO,
251                                                                                                         new PropertyName(
252                                                                                                                           fidSelectPath ),
253                                                                                                         new Literal(
254                                                                                                                      plainIdValue ) );
255    
256                            compOperations.add( propertyTestOperation );
257                        }
258                    } else
259                        LOG.logDebug( "Skipping property '" + propertyName
260                                      + "': not a part of the feature type's identity." );
261                } else if ( propertyValue instanceof Geometry ) {
262    
263                    if ( propertyType.isIdentityPart() ) {
264                        throw new IdGenerationException( "Check for equal geometry properties "
265                                                         + "is not implemented yet. Do not set "
266                                                         + "identityPart to true for geometry properties." );
267                    }
268    
269                } else {
270                    if ( propertyType.isIdentityPart() ) {
271                        LOG.logDebug( "Need to check for simple property '" + propertyName + "' with value '"
272                                      + propertyValue + "'." );
273    
274                        String value = propertyValue.toString();
275                        if ( propertyValue instanceof Date ) {
276                            value = TimeTools.getISOFormattedTime( (Date) propertyValue );
277                        }
278    
279                        PropertyIsCOMPOperation propertyTestOperation = new PropertyIsCOMPOperation(
280                                                                                                     OperationDefines.PROPERTYISEQUALTO,
281                                                                                                     new PropertyName(
282                                                                                                                       propertyName ),
283                                                                                                     new Literal( value ) );
284                        compOperations.add( propertyTestOperation );
285                    } else {
286                        LOG.logDebug( "Skipping property '" + propertyName
287                                      + "': not a part of the feature type's identity." );
288                    }
289                }
290            }
291    
292            if ( ft.getGMLId().isIdentityPart() ) {
293                maybeEqual = false;
294                LOG.logDebug( "Skipping check for identical features: feature id is part of " + "the feature identity." );
295            }
296            if ( maybeEqual ) {
297                // build the filter from the comparison operations
298                Filter filter = null;
299                if ( compOperations.size() == 0 ) {
300                    // no constraints, so any feature of this type will do
301                } else if ( compOperations.size() == 1 ) {
302                    filter = new ComplexFilter( compOperations.get( 0 ) );
303                } else {
304                    LogicalOperation andOperation = new LogicalOperation( OperationDefines.AND, compOperations );
305                    filter = new ComplexFilter( andOperation );
306                }
307                if ( filter != null ) {
308                    LOG.logDebug( "Performing query with filter: " + filter.toXML() );
309                } else {
310                    LOG.logDebug( "Performing unrestricted query." );
311                }
312                Query query = Query.create( new PropertyPath[0], null, null, null, null,
313                                            new QualifiedName[] { feature.getName() }, null, null, filter, 1, 0,
314                                            GetFeature.RESULT_TYPE.RESULTS );
315    
316                try {
317                    FeatureCollection fc = ft.performQuery( query, ta );
318                    if ( fc.size() > 0 ) {
319                        existingFID = fc.getFeature( 0 ).getId();
320                        LOG.logDebug( "Found existing + matching feature with fid: '" + existingFID + "'." );
321                    } else {
322                        LOG.logDebug( "No matching feature found." );
323                    }
324                } catch ( DatastoreException e ) {
325                    throw new IdGenerationException( "Could not perform query to check for "
326                                                     + "existing feature instances: " + e.getMessage(), e );
327                } catch ( UnknownCRSException e ) {
328                    LOG.logError( e.getMessage(), e );
329                }
330            }
331    
332            if ( existingFID != null ) {
333                LOG.logDebug( "Feature '" + feature.getName() + "', FID '" + feature.getId() + "' -> existing FID '"
334                              + existingFID + "'" );
335                feature.setId( existingFID );
336                this.storedFeatures.add( feature );
337                this.reassignedFeatures.add( feature );
338                changeValueForMappedIDProperties( ft, feature );
339            }
340    
341            return existingFID;
342        }
343    
344        /**
345         * TODO: remove parentFID hack
346         *
347         * @param feature
348         * @param parentFID
349         * @throws IdGenerationException
350         */
351        private void generateAndAssignNewFIDs( Feature feature, FeatureId parentFID, DatastoreTransaction ta )
352                                throws IdGenerationException {
353    
354            FeatureId newFid = null;
355            MappedFeatureType ft = (MappedFeatureType) feature.getFeatureType();
356    
357            if ( this.reassignedFeatures.contains( feature ) ) {
358                LOG.logDebug( "Skipping feature with fid '" + feature.getId() + "'. Already reassigned." );
359                return;
360            }
361    
362            this.reassignedFeatures.add( feature );
363            String oldFidValue = feature.getId();
364            if ( oldFidValue == null || "".equals( oldFidValue ) ) {
365                LOG.logDebug( "Feature has no FID. Assigning a new one." );
366            } else {
367                newFid = this.oldFid2NewFidMap.get( oldFidValue );
368            }
369            if ( newFid == null ) {
370                // TODO remove these hacks
371                if ( ft.getGMLId().getIdGenerator() instanceof ParentIDGenerator ) {
372                    newFid = new FeatureId( ft, parentFID.getValues() );
373                } else {
374                    newFid = ft.generateFid( ta );
375                }
376                this.oldFid2NewFidMap.put( oldFidValue, newFid );
377            }
378    
379            LOG.logDebug( "Feature '" + feature.getName() + "', FID '" + oldFidValue + "' -> new FID '" + newFid + "'" );
380            // TODO use FeatureId, not it's String value
381            feature.setId( newFid.getAsString() );
382            changeValueForMappedIDProperties( ft, feature );
383    
384            FeatureProperty[] properties = feature.getProperties();
385            for ( int i = 0; i < properties.length; i++ ) {
386                Object propertyValue = properties[i].getValue();
387                if ( propertyValue instanceof Feature ) {
388                    generateAndAssignNewFIDs( (Feature) propertyValue, newFid, ta );
389                }
390            }
391        }
392    
393        /**
394         * After reassigning a feature id, this method updates all properties of the feature that are mapped to the same
395         * column as the feature id.
396         *
397         * TODO: find a better way to do this
398         *
399         * @param ft
400         * @param feature
401         */
402        private void changeValueForMappedIDProperties( MappedFeatureType ft, Feature feature ) {
403            // TODO remove this hack as well
404            String pkColumn = ft.getGMLId().getIdFields()[0].getField();
405    
406            FeatureProperty[] properties = feature.getProperties();
407            for ( int i = 0; i < properties.length; i++ ) {
408                MappedPropertyType propertyType = (MappedPropertyType) ft.getProperty( properties[i].getName() );
409                if ( propertyType instanceof MappedSimplePropertyType ) {
410                    SimpleContent content = ( (MappedSimplePropertyType) propertyType ).getContent();
411                    if ( content.isUpdateable() ) {
412                        if ( content instanceof MappingField ) {
413                            String column = ( (MappingField) content ).getField();
414                            if ( column.equalsIgnoreCase( pkColumn ) ) {
415                                Object fid = null;
416                                try {
417                                    fid = FeatureId.removeFIDPrefix( feature.getId(), ft.getGMLId() );
418                                } catch ( DatastoreException e ) {
419                                    e.printStackTrace();
420                                }
421                                properties[i].setValue( fid );
422                            }
423                        }
424                    }
425                }
426            }
427        }
428    
429        /**
430         * Checks that the {@link Datastore} contains no feature with the same id as the given feature.
431         *
432         * @param feature
433         * @param ta
434         * @throws IdGenerationException
435         */
436        private void checkForExistingFid( Feature feature, DatastoreTransaction ta )
437                                throws IdGenerationException {
438    
439            MappedFeatureType ft = (MappedFeatureType) feature.getFeatureType();
440            LOG.logDebug( "Checking for existing feature of type: '" + ft.getName() + "' and with fid: '" + feature.getId()
441                          + "'." );
442    
443            // build a filter that matches the feature id
444            FeatureFilter filter = new FeatureFilter();
445            filter.addFeatureId( new org.deegree.model.filterencoding.FeatureId( feature.getId() ) );
446            Query query = Query.create( new PropertyPath[0], null, null, null, null, new QualifiedName[] { ft.getName() },
447                                        null, null, filter, 1, 0, GetFeature.RESULT_TYPE.HITS );
448            try {
449                FeatureCollection fc = ft.performQuery( query, ta );
450                int numFeatures = Integer.parseInt( fc.getAttribute( "numberOfFeatures" ) );
451                if ( numFeatures > 0 ) {
452                    LOG.logInfo( "Found existing feature with fid '" + feature.getId() + "'." );
453                    String msg = "Cannot perform insert: a feature with fid '" + feature.getId()
454                                 + "' already exists in the datastore (and idGen='UseExisting').";
455                    throw new IdGenerationException( msg );
456                }
457                LOG.logDebug( "No feature with fid '" + feature.getId() + "' found." );
458            } catch (IdGenerationException e) {
459                throw e;
460            } catch ( DatastoreException e ) {
461                throw new IdGenerationException( "Could not perform query to check for existing feature instance: "
462                                                 + e.getMessage(), e );
463            } catch ( UnknownCRSException e ) {
464                LOG.logDebug (e.getMessage(), e);
465            }
466        }
467    }