001    //$HeadURL: svn+ssh://jwilden@svn.wald.intevation.org/deegree/base/branches/2.5_testing/src/org/deegree/ogcwebservices/wfs/operation/LockFeature.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.operation;
037    
038    import java.util.ArrayList;
039    import java.util.List;
040    import java.util.Map;
041    
042    import org.deegree.datatypes.QualifiedName;
043    import org.deegree.framework.log.ILogger;
044    import org.deegree.framework.log.LoggerFactory;
045    import org.deegree.i18n.Messages;
046    import org.deegree.model.filterencoding.Filter;
047    import org.deegree.ogcwebservices.InconsistentRequestException;
048    import org.deegree.ogcwebservices.InvalidParameterValueException;
049    import org.deegree.ogcwebservices.MissingParameterValueException;
050    import org.deegree.ogcwebservices.OGCWebServiceException;
051    import org.deegree.ogcwebservices.wfs.WFService;
052    import org.w3c.dom.Element;
053    
054    /**
055     * Represents a <code>LockFeature</code> request to a web feature service.
056     * <p>
057     * Web connections are inherently stateless. Unfortunately, this means that the semantics of serializable transactions
058     * are not preserved. To understand the issue consider an UPDATE operation.
059     * <p>
060     * The client fetches a feature instance. The feature is then modified on the client side, and submitted back to the
061     * database, via a Transaction request for update. Serializability is lost since there is nothing to guarantee that
062     * while the feature was being modified on the client side, another client did not come along and update that same
063     * feature in the database.
064     * <p>
065     * One way to ensure serializability is to require that access to data be done in a mutually exclusive manner; that is
066     * while one transaction accesses a data item, no other transaction can modify the same data item. This can be
067     * accomplished by using locks that control access to the data.
068     * <p>
069     * The purpose of the LockFeature interface is to expose a long term feature locking mechanism to ensure consistency.
070     * The lock is considered long term because network latency would make feature locks last relatively longer than native
071     * commercial database locks.
072     * <p>
073     * The LockFeature interface is optional and need only be implemented if the underlying datastore supports (or can be
074     * made to support) data locking. In addition, the implementation of locking is completely opaque to the client.
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 $
081     */
082    public class LockFeature extends AbstractWFSRequest {
083    
084        private static final long serialVersionUID = 1407310243527517490L;
085    
086        private static final ILogger LOG = LoggerFactory.getLogger( LockFeature.class );
087    
088        /** Default value for expiry (in minutes). */
089        public static String DEFAULT_EXPIRY = "5";
090    
091        /** Duration until timeout (in milliseconds). */
092        private long expiry;
093    
094        private ALL_SOME_TYPE lockAction;
095    
096        private List<Lock> locks;
097    
098        /**
099         * Known lock actions.
100         */
101        public static enum ALL_SOME_TYPE {
102    
103            /**
104             * Acquire a lock on all requested feature instances. If some feature instances cannot be locked, the operation
105             * should fail, and no feature instances should remain locked.
106             */
107            ALL,
108    
109            /**
110             * Lock as many of the requested feature instances as possible.
111             */
112            SOME
113        }
114    
115        /**
116         * String value for {@link ALL_SOME_TYPE ALL_SOME_TYPE.ALL}.
117         */
118        public static String LOCK_ACTION_ALL = "ALL";
119    
120        /**
121         * String value for {@link ALL_SOME_TYPE ALL_SOME_TYPE.SOME}.
122         */
123        public static String LOCK_ACTION_SOME = "SOME";
124    
125        /**
126         * Creates a new <code>LockFeature</code> instance from the given parameters.
127         *
128         * @param version
129         *            request version
130         * @param id
131         *            id of the request
132         * @param handle
133         *            handle of the request
134         * @param expiry
135         *            the limit on how long the web feature service keeps the lock (in milliseconds)
136         * @param lockAction
137         *            method for lock acquisition
138         * @param locks
139         *            contained lock operations
140         */
141        LockFeature( String version, String id, String handle, long expiry, ALL_SOME_TYPE lockAction, List<Lock> locks ) {
142            super( version, id, handle, null );
143            this.expiry = expiry;
144            this.lockAction = lockAction;
145            this.locks = locks;
146        }
147    
148        /**
149         * Creates a new <code>LockFeature</code> instance from the given parameters.
150         *
151         * @param version
152         *            request version
153         * @param id
154         *            id of the request
155         * @param handle
156         *            handle of the request
157         * @param expiry
158         *            the limit on how long the web feature service holds the lock (in milliseconds)
159         * @param lockAction
160         *            method for lock acquisition
161         * @param locks
162         *            contained lock operations
163         * @return new <code>LockFeature</code> request
164         */
165        public static LockFeature create( String version, String id, String handle, long expiry, ALL_SOME_TYPE lockAction,
166                                          List<Lock> locks ) {
167            return new LockFeature( version, id, handle, expiry, lockAction, locks );
168        }
169    
170        /**
171         * Creates a new <code>LockFeature</code> instance from a document that contains the DOM representation of the
172         * request.
173         *
174         * @param id
175         *            of the request
176         * @param root
177         *            element that contains the DOM representation of the request
178         * @return new <code>LockFeature</code> request
179         * @throws OGCWebServiceException
180         */
181        public static LockFeature create( String id, Element root )
182                                throws OGCWebServiceException {
183            LockFeatureDocument doc = new LockFeatureDocument();
184            doc.setRootElement( root );
185            LockFeature request;
186            try {
187                request = doc.parse( id );
188            } catch ( Exception e ) {
189                LOG.logError( e.getMessage(), e );
190                throw new OGCWebServiceException( "LockFeature", e.getMessage() );
191            }
192            return request;
193        }
194    
195        /**
196         * Creates a new <code>LockFeature</code> request from the given parameter map.
197         *
198         * @param kvp
199         *            key-value pairs, keys have to be uppercase
200         * @return new <code>LockFeature</code> request
201         * @throws InconsistentRequestException
202         * @throws InvalidParameterValueException
203         * @throws MissingParameterValueException
204         */
205        public static LockFeature create( Map<String, String> kvp )
206                                throws InconsistentRequestException, InvalidParameterValueException,
207                                MissingParameterValueException {
208    
209            // SERVICE
210            checkServiceParameter( kvp );
211    
212            // ID (deegree specific)
213            String id = kvp.get( "ID" );
214    
215            // VERSION
216            String version = checkVersionParameter( kvp );
217    
218            // TYPENAME
219            QualifiedName[] typeNames = extractTypeNames( kvp );
220            if ( typeNames == null ) {
221                // no TYPENAME parameter -> FEATUREID must be present
222                String featureId = kvp.get( "FEATUREID" );
223                if ( featureId != null ) {
224                    String msg = Messages.getMessage( "WFS_FEATUREID_PARAM_UNSUPPORTED" );
225                    throw new InvalidParameterValueException( msg );
226                }
227                String msg = Messages.getMessage( "WFS_TYPENAME+FID_PARAMS_MISSING" );
228                throw new InvalidParameterValueException( msg );
229            }
230    
231            // EXPIRY
232            String expiryString = getParam( "EXPIRY", kvp, DEFAULT_EXPIRY );
233            int expiry = 0;
234            try {
235                expiry = Integer.parseInt( expiryString );
236                if ( expiry < 1 ) {
237                    throw new NumberFormatException();
238                }
239            } catch ( NumberFormatException e ) {
240                String msg = Messages.getMessage( "WFS_PARAMETER_INVALID_INT", expiryString, "EXPIRY" );
241                throw new InvalidParameterValueException( msg );
242            }
243    
244            // LOCKACTION
245            String lockActionString = getParam( "LOCKACTION", kvp, "ALL" );
246            ALL_SOME_TYPE lockAction = validateLockAction( lockActionString );
247    
248            // BBOX
249            Filter bboxFilter = extractBBOXFilter( kvp );
250    
251            // FILTER (prequisite: TYPENAME)
252            Map<QualifiedName, Filter> filterMap = extractFilters( kvp, typeNames );
253            if ( bboxFilter != null && filterMap.size() > 0 ) {
254                String msg = Messages.getMessage( "WFS_BBOX_FILTER_INVALID" );
255                throw new InvalidParameterValueException( msg );
256            }
257    
258            // build a Lock instance for each requested feature type (later also for each featureid...)
259            List<Lock> locks = new ArrayList<Lock>( typeNames.length );
260            for ( QualifiedName ftName : typeNames ) {
261                Filter filter;
262                if ( bboxFilter != null ) {
263                    filter = bboxFilter;
264                } else {
265                    filter = filterMap.get( ftName );
266                }
267                locks.add( new Lock( null, ftName, filter ) );
268            }
269            return new LockFeature( version, id, null, expiry, lockAction, locks );
270        }
271    
272        /**
273         * Returns the limit on how long the web feature service holds the lock in the event that a transaction is never
274         * issued that would release the lock. The expiry limit is specified in milliseconds.
275         *
276         * @return the limit on how long the web feature service holds the lock (in milliseconds)
277         */
278        public long getExpiry() {
279            return this.expiry;
280        }
281    
282        /**
283         * Returns the mode for lock acquisition.
284         *
285         * @see ALL_SOME_TYPE
286         *
287         * @return the mode for lock acquisition
288         */
289        public ALL_SOME_TYPE getLockAction() {
290            return this.lockAction;
291        }
292    
293        /**
294         * Returns whether this request requires that all features have to be lockable in order to be performed succesfully.
295         *
296         * @see ALL_SOME_TYPE
297         *
298         * @return true, if all features have to be lockable, false otherwise
299         */
300        public boolean lockAllFeatures() {
301            return this.lockAction == ALL_SOME_TYPE.ALL;
302        }
303    
304        /**
305         * Returns the contained lock operations.
306         *
307         * @return the contained lock operations
308         */
309        public List<Lock> getLocks() {
310            return this.locks;
311        }
312    
313        /**
314         * Adds missing namespaces in the names of targeted feature types.
315         * <p>
316         * If the {@link QualifiedName} of a targeted type has a null namespace, the first qualified feature type name of
317         * the given {@link WFService} with the same local name is used instead.
318         * <p>
319         * Note: The method changes this request (the feature type names) and should only be called by the
320         * <code>WFSHandler</code> class.
321         *
322         * @param wfs
323         *            {@link WFService} instance that is used for the lookup of proper (qualified) feature type names
324         */
325        public void guessMissingNamespaces( WFService wfs ) {
326            for ( Lock lock : locks ) {
327                lock.guessMissingNamespaces( wfs );
328            }
329        }
330    
331        /**
332         * Ensures that given lock action <code>String</code> is valid and returns the corresponding {@link ALL_SOME_TYPE}.
333         * <p>
334         * The given <code>String</code> must be either:
335         * <ul>
336         * <li>ALL</li>
337         * <li>SOME</li>
338         * </ul>
339         *
340         * @param lockActionString
341         *            <code>String</code> to validate
342         * @return corresponding {@link ALL_SOME_TYPE}
343         * @throws InvalidParameterValueException
344         *             if string is neither <code>ALL</code> nor <code>SOME</code>
345         */
346        static ALL_SOME_TYPE validateLockAction( String lockActionString )
347                                throws InvalidParameterValueException {
348            ALL_SOME_TYPE lockAction = ALL_SOME_TYPE.ALL;
349            if ( LOCK_ACTION_ALL.equals( lockActionString ) ) {
350                // nothing to do
351            } else if ( LOCK_ACTION_SOME.equals( lockActionString ) ) {
352                lockAction = ALL_SOME_TYPE.SOME;
353            } else {
354                String msg = Messages.getMessage( "WFS_LOCKACTION_INVALID", lockActionString, LOCK_ACTION_ALL,
355                                                  LOCK_ACTION_SOME );
356                throw new InvalidParameterValueException( "LOCKACTION", msg );
357            }
358            return lockAction;
359        }
360    }