/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2009 by Red Hat Inc and/or its affiliates or by
* third-party contributors as indicated by either @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.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*/
package org.hibernate.engine.jdbc.internal;
import java.lang.reflect.Method;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.SQLException;
import java.util.Map;
import org.jboss.logging.Logger;
import org.hibernate.cfg.Environment;
import org.hibernate.engine.jdbc.ContextualLobCreator;
import org.hibernate.engine.jdbc.LobCreationContext;
import org.hibernate.engine.jdbc.LobCreator;
import org.hibernate.engine.jdbc.NonContextualLobCreator;
import org.hibernate.internal.CoreMessageLogger;
import org.hibernate.internal.util.config.ConfigurationHelper;
/**
* Builds {@link LobCreator} instances based on the capabilities of the environment.
*
* @author Steve Ebersole
*/
public class LobCreatorBuilder {
private static final CoreMessageLogger LOG = Logger.getMessageLogger(CoreMessageLogger.class, LobCreatorBuilder.class.getName());
private boolean useContextualLobCreation;
/**
* The public factory method for obtaining the appropriate (according to given JDBC {@link java.sql.Connection}.
*
*
* @param jdbcConnection A JDBC {@link java.sql.Connection} which can be used to gauge the drivers level of support,
* specifically for creating LOB references.
*/
public LobCreatorBuilder(Map configValues, Connection jdbcConnection) {
this.useContextualLobCreation = useContextualLobCreation( configValues, jdbcConnection );
}
private static final Class[] NO_ARG_SIG = new Class[0];
private static final Object[] NO_ARGS = new Object[0];
/**
* Basically here we are simply checking whether we can call the {@link Connection} methods for
* LOB creation added in JDBC 4. We not only check whether the {@link Connection} declares these methods,
* but also whether the actual {@link Connection} instance implements them (i.e. can be called without simply
* throwing an exception).
*
* @param jdbcConnection The connection which can be used in level-of-support testing.
*
* @return True if the connection can be used to create LOBs; false otherwise.
*/
private static boolean useContextualLobCreation(Map configValues, Connection jdbcConnection) {
boolean isNonContextualLobCreationRequired =
ConfigurationHelper.getBoolean( Environment.NON_CONTEXTUAL_LOB_CREATION, configValues );
if ( isNonContextualLobCreationRequired ) {
LOG.disablingContextualLOBCreation( Environment.NON_CONTEXTUAL_LOB_CREATION );
return false;
}
if ( jdbcConnection == null ) {
LOG.disablingContextualLOBCreationSinceConnectionNull();
return false;
}
try {
try {
DatabaseMetaData meta = jdbcConnection.getMetaData();
// if the jdbc driver version is less than 4, it shouldn't have createClob
if ( meta.getJDBCMajorVersion() < 4 ) {
LOG.disablingContextualLOBCreationSinceOldJdbcVersion( meta.getJDBCMajorVersion() );
return false;
}
}
catch ( SQLException ignore ) {
// ignore exception and continue
}
Class connectionClass = Connection.class;
Method createClobMethod = connectionClass.getMethod( "createClob", NO_ARG_SIG );
if ( createClobMethod.getDeclaringClass().equals( Connection.class ) ) {
// If we get here we are running in a jdk 1.6 (jdbc 4) environment...
// Further check to make sure the driver actually implements the LOB creation methods. We
// check against createClob() as indicative of all; should we check against all 3 explicitly?
try {
Object clob = createClobMethod.invoke( jdbcConnection, NO_ARGS );
try {
Method freeMethod = clob.getClass().getMethod( "free", NO_ARG_SIG );
freeMethod.invoke( clob, NO_ARGS );
}
catch ( Throwable ignore ) {
LOG.tracef( "Unable to free CLOB created to test createClob() implementation : %s", ignore );
}
return true;
}
catch ( Throwable t ) {
LOG.disablingContextualLOBCreationSinceCreateClobFailed( t );
}
}
}
catch ( NoSuchMethodException ignore ) {
}
return false;
}
public LobCreator buildLobCreator(LobCreationContext lobCreationContext) {
return useContextualLobCreation
? new ContextualLobCreator( lobCreationContext )
: NonContextualLobCreator.INSTANCE;
}
}