001: /*
002: * $Header: /export/home/cvsroot/MyPersonalizerRepository/MyPersonalizer/Subsystems/Kernel/Sources/es/udc/mypersonalizer/kernel/model/repository/sql/storers/JDBC3AutoIncrementEntityIdentifierGeneratorSingleton.java,v 1.1.1.1 2004/03/25 12:08:36 fbellas Exp $
003: * $Revision: 1.1.1.1 $
004: * $Date: 2004/03/25 12:08:36 $
005: *
006: * =============================================================================
007: *
008: * Copyright (c) 2003, The MyPersonalizer Development Group
009: * (http://www.tic.udc.es/~fbellas/mypersonalizer/index.html) at
010: * University Of A Coruna
011: * All rights reserved.
012: *
013: * Redistribution and use in source and binary forms, with or without
014: * modification, are permitted provided that the following conditions are met:
015: *
016: * - Redistributions of source code must retain the above copyright notice,
017: * this list of conditions and the following disclaimer.
018: *
019: * - Redistributions in binary form must reproduce the above copyright notice,
020: * this list of conditions and the following disclaimer in the documentation
021: * and/or other materials provided with the distribution.
022: *
023: * - Neither the name of the University Of A Coruna nor the names of its
024: * contributors may be used to endorse or promote products derived from
025: * this software without specific prior written permission.
026: *
027: * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
028: * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
029: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
030: * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
031: * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
032: * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
033: * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
034: * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
035: * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
036: * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
037: * POSSIBILITY OF SUCH DAMAGE.
038: *
039: */
040:
041: package es.udc.mypersonalizer.kernel.model.repository.sql.storers;
042:
043: import java.sql.Connection;
044: import java.sql.ResultSet;
045: import java.sql.SQLException;
046: import java.sql.Statement;
047:
048: import es.udc.mypersonalizer.kernel.model.repository.sql.config.DatabaseConventionsConfigManager;
049: import es.udc.mypersonalizer.kernel.model.repository.sql.config.DatabaseSpecificsConfigManager;
050: import es.udc.mypersonalizer.kernel.model.repository.sql.config.DatabaseTemplatesConfig;
051: import es.udc.mypersonalizer.kernel.model.repository.sql.util.SQLOperations;
052: import es.udc.mypersonalizer.kernel.util.exceptions.InternalErrorException;
053:
054: /**
055: * Identifier generator for databases (requires a JDBC3 driver) that provide
056: * auto-increment columns.
057: * <p>
058: * This generator works by inserting a new row on the emulated sequence
059: * (i.e. a table with just one column: an auto-increment column) and retrieving
060: * the generated value.
061: * <p>
062: * It uses
063: * {@link es.udc.mypersonalizer.kernel.model.repository.sql.config.DatabaseTemplatesConfig#getInsertId(String)}
064: * to obtain the query to insert the row and JDBC3's
065: * {@link java.sql.Statement#getGeneratedKeys()} to retrieve the generated
066: * identifier.
067: *
068: * @author Abel Muinho
069: * @author Fernando Bellas
070: * @since 1.0
071: */
072: public class JDBC3AutoIncrementEntityIdentifierGeneratorSingleton
073: extends EntityIdentifierGeneratorSingleton {
074:
075: private String sequenceSuffix;
076:
077: private DatabaseTemplatesConfig databaseTemplates;
078:
079: public JDBC3AutoIncrementEntityIdentifierGeneratorSingleton()
080: throws InternalErrorException {
081: super ();
082: sequenceSuffix = DatabaseConventionsConfigManager.getConfig()
083: .getSequenceSuffix();
084: databaseTemplates = DatabaseSpecificsConfigManager.getConfig()
085: .getDatabaseTemplatesConfig();
086: }
087:
088: public Long nextIdentifier(Connection connection,
089: String entityTableName) throws InternalErrorException {
090:
091: Statement statement = null;
092: ResultSet resultSet = null;
093:
094: try {
095:
096: String sequenceName = entityTableName + sequenceSuffix;
097: String insertString = databaseTemplates
098: .getInsertId(sequenceName);
099: ;
100:
101: /* Insert an empty row to generate a new identifier. */
102: statement = connection.createStatement();
103: statement.executeUpdate(insertString,
104: Statement.RETURN_GENERATED_KEYS);
105: resultSet = statement.getGeneratedKeys();
106:
107: /* Get and return the generated identifier. */
108: if (!resultSet.next()) {
109: throw new InternalErrorException(
110: "JDBC driver do not return generated keys.");
111: }
112: Long generatedKey = new Long(resultSet.getLong(1));
113:
114: return generatedKey;
115:
116: } catch (SQLException e) {
117: throw new InternalErrorException(e);
118: } finally {
119: SQLOperations.closeResultSet(resultSet);
120: SQLOperations.closeStatement(statement);
121: }
122: }
123:
124: }
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