001    //$HeadURL: svn+ssh://rbezema@svn.wald.intevation.org/deegree/base/branches/2.2_testing/src/org/deegree/io/datastore/sql/idgenerator/DBSeqIdGenerator.java $
002    /*----------------    FILE HEADER  ------------------------------------------
003    
004     This file is part of deegree.
005     Copyright (C) 2001-2008 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: apoth $
064     * 
065     * @version $Revision: 9342 $, $Date: 2007-12-27 13:32:57 +0100 (Do, 27 Dez 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 the name of the used sequence.
101         * 
102         * @return the name of the used sequence
103         */
104        public String getSequenceName() {
105            return this.sequenceName;
106        }
107    
108        /**
109         * Returns a new primary key.
110         * 
111         * @param ta
112         *            datastore transaction (context)
113         * @return a new primary key.
114         * @throws IdGenerationException
115         *             if the generation of the id could not be performed
116         */
117        @Override
118        public Object getNewId( DatastoreTransaction ta )
119                                throws IdGenerationException {
120            if ( !( ta instanceof SQLTransaction ) ) {
121                throw new IllegalArgumentException( "DBSeqIdGenerator can only be used with SQL datastores." );
122            }
123    
124            Object pk;
125            try {
126                AbstractSQLDatastore ds = (AbstractSQLDatastore) ta.getDatastore();
127                Connection conn = ( (SQLTransaction) ta ).getConnection();
128                pk = ds.getSequenceNextVal( conn, this.sequenceName );
129            } catch ( DatastoreException e ) {
130                throw new IdGenerationException( e.getMessage(), e );
131            }
132            return pk;
133        }
134    
135        /**
136         * Returns a new id for a feature of the given type.
137         * 
138         * @param ft
139         *            (mapped) feature type
140         * @return a new feature id.
141         * @throws IdGenerationException
142         *             if the generation of the id could not be performed
143         */
144        @Override
145        public FeatureId getNewId( MappedFeatureType ft, DatastoreTransaction ta )
146                                throws IdGenerationException {
147    
148            MappedGMLId fidDefinition = ft.getGMLId();
149            if ( fidDefinition.getKeySize() != 1 ) {
150                throw new IdGenerationException( "Cannot generate feature ids that are mapped to "
151                                                 + fidDefinition.getKeySize() + " columns." );
152            }
153    
154            Datastore ds = ft.getGMLSchema().getDatastore();
155            if ( !( ds instanceof AbstractSQLDatastore ) ) {
156                throw new IllegalArgumentException( "DBSeqIdGenerator can only be used with SQL datastores." );
157            }
158    
159            Object fidNucleus;
160            try {
161                fidNucleus = ( (AbstractSQLDatastore) ds ).getSequenceNextVal( ( (SQLTransaction) ta ).getConnection(),
162                                                                               this.sequenceName );
163            } catch ( DatastoreException e ) {
164                throw new IdGenerationException( e.getMessage(), e );
165            }
166    
167            FeatureId fid = new FeatureId( ft, new Object[] { fidNucleus } );
168            return fid;
169        }
170    }