001    //$HeadURL: svn+ssh://jwilden@svn.wald.intevation.org/deegree/base/branches/2.5_testing/src/org/deegree/io/datastore/sql/idgenerator/DBSeqIdGenerator.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.sql.idgenerator;
037    
038    import java.sql.Connection;
039    import java.util.Properties;
040    
041    import org.deegree.io.datastore.Datastore;
042    import org.deegree.io.datastore.DatastoreException;
043    import org.deegree.io.datastore.DatastoreTransaction;
044    import org.deegree.io.datastore.FeatureId;
045    import org.deegree.io.datastore.idgenerator.IdGenerationException;
046    import org.deegree.io.datastore.idgenerator.IdGenerator;
047    import org.deegree.io.datastore.schema.MappedFeatureType;
048    import org.deegree.io.datastore.schema.MappedGMLId;
049    import org.deegree.io.datastore.sql.AbstractSQLDatastore;
050    import org.deegree.io.datastore.sql.transaction.SQLTransaction;
051    
052    /**
053     * Feature id generator that uses an SQL sequence to create new values.
054     *
055     * @author <a href="mailto:schneider@lat-lon.de">Markus Schneider </a>
056     * @author last edited by: $Author: mschneider $
057     *
058     * @version $Revision: 18195 $, $Date: 2009-06-18 17:55:39 +0200 (Do, 18 Jun 2009) $
059     */
060    public class DBSeqIdGenerator extends IdGenerator {
061    
062        private String sequenceName;
063    
064        private int offset = -1;
065    
066        /**
067         * Creates a new <code>DBSeqIdGenerator</code> instance.
068         * <p>
069         * Supported configuration parameters:
070         * <table border="1">
071         * <tr>
072         * <th>Name</th>
073         * <th>optional?</th>
074         * <th>Usage</th>
075         * </tr>
076         * <tr>
077         * <td>sequence</td>
078         * <td>no</td>
079         * <td>name of the SQL sequence to be used</td>
080         * </tr>
081         * <tr>
082         * <td>offset</td>
083         * <td>yes</td>
084         * <td>integer value, if omitted the next value of the sequence is used (default)<br>
085         * otherwise the current value + offset is used</td>
086         * </tr>
087         * </table>
088         *
089         * @param params
090         *            configuration parameters
091         * @throws IdGenerationException
092         */
093        public DBSeqIdGenerator( Properties params ) throws IdGenerationException {
094            super( params );
095            this.sequenceName = params.getProperty( "sequence" );
096            if ( this.sequenceName == null ) {
097                throw new IdGenerationException( "DBSeqIdGenerator requires 'sequence' parameter." );
098            }
099            String offsetString = params.getProperty( "offset" );
100            if ( offsetString != null ) {
101                try {
102                    offset = Integer.parseInt( offsetString );
103                } catch ( NumberFormatException e ) {
104                    throw new IdGenerationException( "DBSeqIdGenerator 'offset' parameter must be an integer value." );
105                }
106            }
107        }
108    
109        /**
110         * Returns the name of the used sequence.
111         *
112         * @return the name of the used sequence
113         */
114        public String getSequenceName() {
115            return this.sequenceName;
116        }
117    
118        /**
119         * Returns a new primary key.
120         *
121         * @param ta
122         *            datastore transaction (context)
123         * @return a new primary key.
124         * @throws IdGenerationException
125         *             if the generation of the id could not be performed
126         */
127        @Override
128        public Object getNewId( DatastoreTransaction ta )
129                                throws IdGenerationException {
130            if ( !( ta instanceof SQLTransaction ) ) {
131                throw new IllegalArgumentException( "DBSeqIdGenerator can only be used with SQL datastores." );
132            }
133    
134            Object pk;
135            try {
136                AbstractSQLDatastore ds = (AbstractSQLDatastore) ta.getDatastore();
137                Connection conn = ( (SQLTransaction) ta ).getConnection();
138                if (offset == -1) {
139                    pk = ds.getSequenceNextVal( conn, this.sequenceName );
140                } else {
141                    pk = ds.getSequenceCurrValPlusOffset( conn, this.sequenceName, offset );
142                }
143            } catch ( DatastoreException e ) {
144                throw new IdGenerationException( e.getMessage(), e );
145            }
146            return pk;
147        }
148    
149        /**
150         * Returns a new id for a feature of the given type.
151         *
152         * @param ft
153         *            (mapped) feature type
154         * @return a new feature id.
155         * @throws IdGenerationException
156         *             if the generation of the id could not be performed
157         */
158        @Override
159        public FeatureId getNewId( MappedFeatureType ft, DatastoreTransaction ta )
160                                throws IdGenerationException {
161    
162            MappedGMLId fidDefinition = ft.getGMLId();
163            if ( fidDefinition.getKeySize() != 1 ) {
164                throw new IdGenerationException( "Cannot generate feature ids that are mapped to "
165                                                 + fidDefinition.getKeySize() + " columns." );
166            }
167    
168            Datastore ds = ft.getGMLSchema().getDatastore();
169            if ( !( ds instanceof AbstractSQLDatastore ) ) {
170                throw new IllegalArgumentException( "DBSeqIdGenerator can only be used with SQL datastores." );
171            }
172    
173            Object fidNucleus;
174            try {
175                fidNucleus = ( (AbstractSQLDatastore) ds ).getSequenceNextVal( ( (SQLTransaction) ta ).getConnection(),
176                                                                               this.sequenceName );
177            } catch ( DatastoreException e ) {
178                throw new IdGenerationException( e.getMessage(), e );
179            }
180    
181            FeatureId fid = new FeatureId( ft, new Object[] { fidNucleus } );
182            return fid;
183        }
184    }