001    //$HeadURL: svn+ssh://rbezema@svn.wald.intevation.org/deegree/base/tags/2.1/src/org/deegree/io/datastore/sql/idgenerator/DBSeqIdGenerator.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.sql.idgenerator;
044    
045    import java.sql.Connection;
046    import java.util.Properties;
047    
048    import org.deegree.io.datastore.Datastore;
049    import org.deegree.io.datastore.DatastoreException;
050    import org.deegree.io.datastore.DatastoreTransaction;
051    import org.deegree.io.datastore.FeatureId;
052    import org.deegree.io.datastore.idgenerator.IdGenerationException;
053    import org.deegree.io.datastore.idgenerator.IdGenerator;
054    import org.deegree.io.datastore.schema.MappedFeatureType;
055    import org.deegree.io.datastore.schema.MappedGMLId;
056    import org.deegree.io.datastore.sql.AbstractSQLDatastore;
057    import org.deegree.io.datastore.sql.transaction.SQLTransaction;
058    
059    /**
060     * Feature id generator that uses an SQL sequence to create new values.
061     * 
062     * @author <a href="mailto:schneider@lat-lon.de">Markus Schneider </a>
063     * @author last edited by: $Author: mschneider $
064     * 
065     * @version $Revision: 6588 $, $Date: 2007-04-11 17:31:29 +0200 (Mi, 11 Apr 2007) $
066     */
067    public class DBSeqIdGenerator extends IdGenerator {
068    
069        private String sequenceName;
070    
071        /**
072         * Creates a new <code>DBSeqIdGenerator</code> instance.
073         * <p>
074         * Supported configuration parameters: <table>
075         * <tr>
076         * <th>Name</th>
077         * <th>optional?</th>
078         * <th>Usage</th>
079         * </tr>
080         * <tr>
081         * <td>sequence</td>
082         * <td>no</td>
083         * <td>name of the SQL sequence to be used</td>
084         * </tr>
085         * </table>
086         * 
087         * @param params
088         *            configuration parameters
089         * @throws IdGenerationException
090         */
091        public DBSeqIdGenerator( Properties params ) throws IdGenerationException {
092            super( params );
093            this.sequenceName = params.getProperty( "sequence" );
094            if ( this.sequenceName == null ) {
095                throw new IdGenerationException( "DBSeqIdGenerator requires 'sequence' parameter." );
096            }
097        }
098    
099        /**
100         * Returns a new primary key.
101         * 
102         * @param ta
103         *            datastore transaction (context)
104         * @return a new primary key.
105         * @throws IdGenerationException
106         *             if the generation of the id could not be performed
107         */
108        @Override
109        public Object getNewId( DatastoreTransaction ta )
110                                throws IdGenerationException {
111            if ( !( ta instanceof SQLTransaction ) ) {
112                throw new IllegalArgumentException( "DBSeqIdGenerator can only be used with SQL datastores." );
113            }
114    
115            Object pk;
116            try {
117                AbstractSQLDatastore ds = (AbstractSQLDatastore) ta.getDatastore();
118                Connection conn = ( (SQLTransaction) ta ).getConnection();
119                pk = ds.getSequenceNextVal( conn, this.sequenceName );
120            } catch ( DatastoreException e ) {
121                throw new IdGenerationException( e.getMessage(), e );
122            }
123            return pk;
124        }
125    
126        /**
127         * Returns a new id for a feature of the given type.
128         * 
129         * @param ft
130         *            (mapped) feature type
131         * @return a new feature id.
132         * @throws IdGenerationException
133         *             if the generation of the id could not be performed
134         */
135        @Override
136        public FeatureId getNewId( MappedFeatureType ft, DatastoreTransaction ta )
137                                throws IdGenerationException {
138    
139            MappedGMLId fidDefinition = ft.getGMLId();
140            if ( fidDefinition.getKeySize() != 1 ) {
141                throw new IdGenerationException( "Cannot generate feature ids that are mapped to "
142                                                 + fidDefinition.getKeySize() + " columns." );
143            }
144    
145            Datastore ds = ft.getGMLSchema().getDatastore();
146            if ( !( ds instanceof AbstractSQLDatastore ) ) {
147                throw new IllegalArgumentException( "DBSeqIdGenerator can only be used with SQL datastores." );
148            }
149    
150            Object fidNucleus;
151            try {
152                fidNucleus = ( (AbstractSQLDatastore) ds ).getSequenceNextVal( ( (SQLTransaction) ta ).getConnection(),
153                                                                               this.sequenceName );
154            } catch ( DatastoreException e ) {
155                throw new IdGenerationException( e.getMessage(), e );
156            }
157    
158            FeatureId fid = new FeatureId( ft, new Object[] { fidNucleus } );
159            return fid;
160        }
161    }