001    //$HeadURL: svn+ssh://jwilden@svn.wald.intevation.org/deegree/base/branches/2.5_testing/src/org/deegree/portal/standard/wfs/control/GeometryValidator.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    
037    package org.deegree.portal.standard.wfs.control;
038    
039    import javax.servlet.http.HttpServletRequest;
040    
041    import org.deegree.enterprise.control.AbstractListener;
042    import org.deegree.enterprise.control.FormEvent;
043    import org.deegree.enterprise.control.RPCParameter;
044    import org.deegree.enterprise.control.RPCStruct;
045    import org.deegree.enterprise.control.RPCUtils;
046    import org.deegree.enterprise.control.RPCWebEvent;
047    import org.deegree.framework.log.ILogger;
048    import org.deegree.framework.log.LoggerFactory;
049    import org.deegree.i18n.Messages;
050    import org.deegree.model.spatialschema.Geometry;
051    import org.deegree.model.spatialschema.JTSAdapter;
052    import org.deegree.model.spatialschema.WKTAdapter;
053    import org.deegree.portal.PortalException;
054    
055    import com.vividsolutions.jts.algorithm.CGAlgorithms;
056    
057    /**
058     * This listener validates simple geometries. The geometries to be validated are passed in as the value of the
059     * <code>'GEOMETRY'</code> parameter of such an RPC request:
060     *
061     * <pre>
062     *   &lt;methodCall&gt;
063     *   &lt;methodName&gt;dig:checkGeometry&lt;/methodName&gt;
064     *   &lt;params&gt;
065     *   &lt;param&gt;&lt;value&gt;&lt;struct&gt;&lt;member&gt;
066     *   &lt;name&gt;GEOMETRY&lt;/name&gt;
067     *   &lt;value&gt;&lt;string&gt;POLYGON(( 7.38 49.64, 12.03 48.7, 11.34 51.66, 11.34 51.66, 7.38 49.64 ))&lt;/string&gt;&lt;/value&gt;
068     *   &lt;/member&gt;&lt;/struct&gt;&lt;/value&gt;&lt;/param&gt;
069     *   &lt;/params&gt;
070     *   &lt;/methodCall&gt;
071     * </pre>
072     *
073     * Subclasses may override {@link #validateRequest( RPCWebEvent rpcEvent )},
074     * {@link #createGeometry( RPCWebEvent rpcEvent )} and/or validateGeometry() if they want to change the behaviour
075     * regarding request validation, geometry creation and/or geometry validation, respectively. Especially the last method
076     * may be different according to use-cases. The result of the validation is put in the session under the key
077     * <code>GeometryValidator.GEOMETRY_STATE</code>.
078     *
079     * @author <a href="mailto:taddei@lat-lon.de">Ugo Taddei</a>
080     * @author last edited by: $Author: mschneider $
081     *
082     * @version $Revision: 18195 $, $Date: 2009-06-18 17:55:39 +0200 (Do, 18 Jun 2009) $
083     */
084    public class GeometryValidator extends AbstractListener {
085    
086        private static final ILogger LOG = LoggerFactory.getLogger( GeometryValidator.class );
087    
088        /** Attribute name for the geometry validity state */
089        public static final String GEOMETRY_STATE = "GEOMETRY_STATE";
090    
091        /** Indicates that the geometry is perfectly valid */
092        public static final String VALID_GEOMETRY = "VALID_GEOMETRY";
093    
094        /** Indicates that the geometry is invalid (self intersection, missing points, etc) */
095        public static final String INVALID_GEOMETRY = "INVALID_GEOMETRY";
096    
097        /** Indicates that the geometry is OK, although it may not be considered formally correct in most GIS contexts. */
098        public static final String INFORMALLY_VALID_GEOMETRY = "INFORMALLY_VALID_GEOMETRY";
099    
100        protected Geometry geometry;
101    
102        /**
103         * This method validates the RPC-encoded request ({@link #validateRequest(RPCWebEvent)}), create some geometry
104         * from the request parameters ({@link #createGeometry(RPCWebEvent)} and then validate this geometry ({@link #validateGeometry()}.
105         * The result of this validate is made available to the request object as an attribute under the key
106         * <code>GeometryValidator.GEOMETRY_STATE</code>.
107         *
108         * @param event
109         *            the event containing the RPC-emcoded request.
110         */
111        @Override
112        public void actionPerformed( FormEvent event ) {
113    
114            RPCWebEvent rpcEvent = (RPCWebEvent) event;
115    
116            try {
117                validateRequest( rpcEvent );
118            } catch ( Exception e ) {
119                LOG.logError( e.getMessage(), e );
120                gotoErrorPage( Messages.getMessage( "IGEO_STD_INVALID_RPC", e.getLocalizedMessage() ) );
121                return;
122            }
123    
124            Object validationResult = INVALID_GEOMETRY;
125    
126            try {
127                geometry = createGeometry( rpcEvent );
128            } catch ( Exception e ) {
129                // do not consider this as an exception - and thus return the error
130                // mesg back to the page -, but as a failure to create a valid geometry
131                LOG.logDebug( e.getMessage(), e );
132            }
133    
134            try {
135                validationResult = validateGeometry();
136            } catch ( Exception e ) {
137                LOG.logError( e.getMessage(), e );
138                // TODO i18nize
139                gotoErrorPage( e.getLocalizedMessage() );
140                return;
141            }
142    
143            HttpServletRequest req = (HttpServletRequest) getRequest();
144            req.setAttribute( GEOMETRY_STATE, validationResult );
145        }
146    
147        /**
148         * Validates the incoming RPc request. This method looks for an RPC parameter (struct) named <code>'GEOMETRY'</code>,
149         * checks if the valeu is empty and looks no further. The expected value is a well-known geometry representation.
150         *
151         * @param rpcEvent
152         *            the event containing at least a struct with a string type parameter named <code>'GEOMETRY'</code>.
153         * @throws Exception
154         *             If no such parameter is found or if the value is empty. This is interpreted as an exception and the
155         *             resulting message is sent back to the client.
156         */
157        protected void validateRequest( RPCWebEvent rpcEvent )
158                                throws Exception {
159    
160            RPCParameter[] pars = rpcEvent.getRPCMethodCall().getParameters();
161            if ( pars == null || pars.length != 1 ) {
162                throw new PortalException( "The RPC request must contain a 'GEOMETRY' parameter." );
163            }
164            RPCStruct struct = (RPCStruct) pars[0].getValue();
165    
166            String geomString = RPCUtils.getRpcPropertyAsString( struct, "GEOMETRY" );
167            if ( geomString == null || geomString.length() == 0 ) {
168                // TODO i18nize
169                throw new PortalException( "The RPC request does not contains a well-known "
170                                           + " text representation of a geometry." );
171            }
172        }
173    
174        /**
175         * Creates the geometry from the data provided it the request (rpcEvent).
176         *
177         * @see #validateRequest(RPCWebEvent)
178         * @param rpcEvent
179         *            the <code>RPCWebEvent</code> conatining the request
180         * @return a new geometry. This method uses {@link WKTAdapter#wrap(String, org.deegree.model.crs.CoordinateSystem)}
181         *         to create the new <code>Geometry</code>.
182         * @throws Exception
183         *             if the <code>Geometry</code> creation failed.
184         */
185        protected Geometry createGeometry( RPCWebEvent rpcEvent )
186                                throws Exception {
187            RPCParameter[] pars = rpcEvent.getRPCMethodCall().getParameters();
188            RPCStruct struct = (RPCStruct) pars[0].getValue();
189            String geomString = RPCUtils.getRpcPropertyAsString( struct, "GEOMETRY" );
190            LOG.logDebug( "Digitized geometry: \n" + geomString );
191            return WKTAdapter.wrap( geomString, null );
192        }
193    
194        /**
195         * Validates this object's <code>Geometry</code> and return an object, preferably a code, indicating the validity
196         * state of the geometry. There are three type of geometry validity states.
197         * <ul>
198         * <li><code>GeometryValidator.VALID_GEOMETRY</code>: The geometry is perfecly OK,</li>
199         * <li><code>GeometryValidator.INVALID_GEOMETRY</code>: The geometry is not OK (self intersection, missing
200         * points, etc),</li>
201         * <li><code>GeometryValidator.INFORMALLY_VALID_GEOMETRY</code>: The geometry is OK, although it may not be
202         * considered formally correct in most GIS contexts. For example, polygons are supposed to have counter-clockwise
203         * outter rings, lines may no self-intersect, etc.</li>
204         * </ul>
205         * <br/> The meaning of those may also vary according to the use-case, e.g. a polygon that is counter-clockwise but
206         * is required to have at least 4 vertices. <br/> This method employs the Java Topology Suite to check for geometry
207         * validity ({@link com.vividsolutions.jts.geom.Geometry#isValid()}) and, in the case of polygons, for the order
208         * of the coordinates (in other words, whether they are counter-clockwise}. <br/> The result of the validation is
209         * available in the request under the key <code>GeometryValidator.GEOMETRY_STATE</code>.
210         *
211         * @return the geometry's validity state
212         */
213        protected Object validateGeometry() {
214    
215            String result = INVALID_GEOMETRY;
216    
217            try {
218                com.vividsolutions.jts.geom.Geometry jtsGeom = JTSAdapter.export( geometry );
219                if ( jtsGeom.isValid() ) { // means is OK, really
220                    result = VALID_GEOMETRY;
221                    if ( jtsGeom instanceof com.vividsolutions.jts.geom.Polygon ) {
222                        if ( !CGAlgorithms.isCCW( jtsGeom.getCoordinates() ) ) {
223                            result = INFORMALLY_VALID_GEOMETRY;
224                        }
225                    }
226                }
227            } catch ( Exception e ) {
228                LOG.logError( e.getLocalizedMessage(), e );
229                // just in case
230                result = INVALID_GEOMETRY;
231            }
232    
233            LOG.logInfo( "Geometry validation result: " + result );
234    
235            return result;
236        }
237    }