/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2010, Red Hat Inc. or third-party contributors as
 * indicated by the @author tags or express copyright attribution
 * statements applied by the authors.  All third-party contributions are
 * distributed under license by Red Hat Inc.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 * for more details.
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 * You should have received a copy of the GNU Lesser General Public License
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package org.hibernate.id;

import java.io.Serializable;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Properties;

import org.hibernate.HibernateException;
import org.hibernate.MappingException;
import org.hibernate.cfg.ObjectNameNormalizer;
import org.hibernate.dialect.Dialect;
import org.hibernate.engine.spi.SessionImplementor;
import org.hibernate.internal.util.config.ConfigurationHelper;
import org.hibernate.mapping.Table;
import org.hibernate.type.Type;

import org.jboss.logging.Logger;

sequence

Generates long values using an oracle-style sequence. A higher performance algorithm is SequenceHiLoGenerator.

Mapping parameters supported: sequence, parameters.
Author:Gavin King
See Also:
  • SequenceHiLoGenerator
/** * <b>sequence</b><br> * <br> * Generates <tt>long</tt> values using an oracle-style sequence. A higher * performance algorithm is <tt>SequenceHiLoGenerator</tt>.<br> * <br> * Mapping parameters supported: sequence, parameters. * * @see SequenceHiLoGenerator * @author Gavin King */
public class SequenceGenerator implements PersistentIdentifierGenerator, BulkInsertionCapableIdentifierGenerator, Configurable { private static final Logger LOG = Logger.getLogger( SequenceGenerator.class.getName() );
The sequence parameter
/** * The sequence parameter */
public static final String SEQUENCE = "sequence";
The parameters parameter, appended to the create sequence DDL. For example (Oracle): INCREMENT BY 1 START WITH 1 MAXVALUE 100 NOCACHE.
/** * The parameters parameter, appended to the create sequence DDL. * For example (Oracle): <tt>INCREMENT BY 1 START WITH 1 MAXVALUE 100 NOCACHE</tt>. */
public static final String PARAMETERS = "parameters"; private String sequenceName; private String parameters; private Type identifierType; private String sql; protected Type getIdentifierType() { return identifierType; } public Object generatorKey() { return getSequenceName(); } public String getSequenceName() { return sequenceName; } @Override public void configure(Type type, Properties params, Dialect dialect) throws MappingException { ObjectNameNormalizer normalizer = ( ObjectNameNormalizer ) params.get( IDENTIFIER_NORMALIZER ); sequenceName = normalizer.normalizeIdentifierQuoting( ConfigurationHelper.getString( SEQUENCE, params, "hibernate_sequence" ) ); parameters = params.getProperty( PARAMETERS ); if ( sequenceName.indexOf( '.' ) < 0 ) { final String schemaName = normalizer.normalizeIdentifierQuoting( params.getProperty( SCHEMA ) ); final String catalogName = normalizer.normalizeIdentifierQuoting( params.getProperty( CATALOG ) ); sequenceName = Table.qualify( dialect.quote( catalogName ), dialect.quote( schemaName ), dialect.quote( sequenceName ) ); } else { // if already qualified there is not much we can do in a portable manner so we pass it // through and assume the user has set up the name correctly. } this.identifierType = type; sql = dialect.getSequenceNextValString( sequenceName ); } @Override public Serializable generate(SessionImplementor session, Object obj) { return generateHolder( session ).makeValue(); } protected IntegralDataTypeHolder generateHolder(SessionImplementor session) { try { PreparedStatement st = session.getTransactionCoordinator().getJdbcCoordinator().getStatementPreparer().prepareStatement( sql ); try { ResultSet rs = session.getTransactionCoordinator().getJdbcCoordinator().getResultSetReturn().extract( st ); try { rs.next(); IntegralDataTypeHolder result = buildHolder(); result.initialize( rs, 1 ); LOG.debugf( "Sequence identifier generated: %s", result ); return result; } finally { session.getTransactionCoordinator().getJdbcCoordinator().release( rs, st ); } } finally { session.getTransactionCoordinator().getJdbcCoordinator().release( st ); } } catch (SQLException sqle) { throw session.getFactory().getSQLExceptionHelper().convert( sqle, "could not get next sequence value", sql ); } } protected IntegralDataTypeHolder buildHolder() { return IdentifierGeneratorHelper.getIntegralDataTypeHolder( identifierType.getReturnedClass() ); } @Override @SuppressWarnings( {"deprecation"}) public String[] sqlCreateStrings(Dialect dialect) throws HibernateException { String[] ddl = dialect.getCreateSequenceStrings( sequenceName ); if ( parameters != null ) { ddl[ddl.length - 1] += ' ' + parameters; } return ddl; } @Override public String[] sqlDropStrings(Dialect dialect) throws HibernateException { return dialect.getDropSequenceStrings(sequenceName); } @Override public boolean supportsBulkInsertionIdentifierGeneration() { return true; } @Override public String determineBulkInsertionIdentifierGenerationSelectFragment(Dialect dialect) { return dialect.getSelectSequenceNextValString( getSequenceName() ); } }