001    //$HeadURL: svn+ssh://rbezema@svn.wald.intevation.org/deegree/base/tags/2.1/src/org/deegree/io/datastore/idgenerator/UUIDGenerator.java $
002    /*----------------    FILE HEADER  ------------------------------------------
003    
004     This file is part of deegree.
005     Copyright (C) 2001-2006 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     Aennchenstraße 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.io.datastore.idgenerator;
044    
045    import java.util.Properties;
046    import java.util.UUID;
047    
048    import org.deegree.datatypes.Types;
049    import org.deegree.io.datastore.DatastoreTransaction;
050    import org.deegree.io.datastore.FeatureId;
051    import org.deegree.io.datastore.schema.MappedFeatureType;
052    import org.deegree.io.datastore.schema.MappedGMLId;
053    
054    /**
055     * Primary key and {@link FeatureId} generator that is based on UUIDs. 
056     * 
057     * @author <a href="mailto:schneider@lat-lon.de">Markus Schneider </a>
058     * @author last edited by: $Author: apoth $
059     * 
060     * @version $Revision: 7843 $, $Date: 2007-07-25 09:44:47 +0200 (Mi, 25 Jul 2007) $
061     */
062    public class UUIDGenerator extends IdGenerator {
063    
064        private UUID factory;
065    
066        /**
067         * Creates a new <code>UUIDGenerator</code> instance.
068         * <p>
069         * Supported configuration parameters:
070         * <table>
071         *   <tr><th>Name</th><th>optional?</th><th>Usage</th></tr>
072         *   <tr><td>macAddress</td><td>yes</td><td>specify MAC address component of UUID</td></tr>
073         * </table>
074         * 
075         * @param params
076         *            configuration parameters
077         * @throws IdGenerationException 
078         */
079        public UUIDGenerator( Properties params ) throws IdGenerationException {
080            super( params );
081            String macAddress = params.getProperty( "macAddress" );
082            if ( macAddress != null ) {
083                long decoded;
084                try {
085                    decoded = Long.decode( macAddress );
086                } catch ( NumberFormatException e ) {
087                    throw new IdGenerationException( "Value for parameter 'macAddress': '" + macAddress
088                                                     + "' can not be decoded as Long." );
089                }
090                factory = new UUID( decoded, (long)(Math.random() * Long.MAX_VALUE) );
091            } else {
092                factory = UUID.randomUUID();
093            }
094        }
095    
096        /**
097         * Returns a new primary key.
098         * 
099         * @param ta
100         *            datastore transaction (context)
101         * @return a new primary key.
102         * @throws IdGenerationException
103         *             if the generation of the id could not be performed
104         */
105        @Override
106        public String getNewId( DatastoreTransaction ta )
107                                throws IdGenerationException {
108            return "UUID_" + factory.toString();
109        }
110    
111        /**
112         * Returns a new id for a feature of the given type.
113         * 
114         * @param ft
115         *            (mapped) feature type (irrelevant for this generator)
116         * @param ta
117         *            datastore transaction (context)
118         * @return a new feature id.
119         * @throws IdGenerationException 
120         */
121        @Override
122        public FeatureId getNewId( MappedFeatureType ft, DatastoreTransaction ta )
123                                throws IdGenerationException {
124    
125            FeatureId fid = null;
126    
127            MappedGMLId fidDefinition = ft.getGMLId();
128            if ( fidDefinition.getKeySize() != 1 ) {
129                throw new IdGenerationException( "Cannot generate feature ids that are mapped to "
130                                                 + fidDefinition.getKeySize() + " columns." );
131            }
132            if ( fidDefinition.getIdFields()[0].getType() == Types.VARCHAR ||
133                 fidDefinition.getIdFields()[0].getType() == Types.CHAR ) {
134                String uuidString = "UUID_" + factory.toString();
135                fid = new FeatureId( ft, new Object[] { uuidString } );
136            } else {
137                // TODO add handling of NUMERIC columns (>= 128 bit)
138                throw new IdGenerationException( "UUIDGenerator may currently only be used for VARCHAR fields." );
139            }
140            return fid;
141        }
142    }