/*
* $Id$
*
* This file is part of the OpenLink Software Virtuoso Open-Source (VOS)
* project.
*
* Copyright (C) 1998-2012 OpenLink Software
*
* This project is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; only version 2 of the License, dated June 1991.
*
* 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
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
package virtuoso.jena.driver;
import java.sql.Connection;
import java.sql.SQLException;
import com.hp.hpl.jena.graph.impl.TransactionHandlerBase;
import com.hp.hpl.jena.shared.JenaException;
public class VirtTransactionHandler extends TransactionHandlerBase {
private VirtGraph graph = null;
private Boolean m_transactionsSupported = null;
public VirtTransactionHandler(VirtGraph _graph) {
super();
this.graph = _graph;
}
public boolean transactionsSupported() {
if (m_transactionsSupported != null) {
return (m_transactionsSupported.booleanValue());
}
try {
Connection c = graph.getConnection();
if (c != null) {
m_transactionsSupported = new Boolean(c.getMetaData()
.supportsMultipleTransactions());
return (m_transactionsSupported.booleanValue());
}
} catch (Exception e) {
throw new JenaException(e);
}
return (false);
}
public void begin() {
if (transactionsSupported()) {
try {
Connection c = graph.getConnection();
if (c.getTransactionIsolation() != Connection.TRANSACTION_READ_COMMITTED) {
c.setTransactionIsolation(Connection.TRANSACTION_READ_COMMITTED);
}
if (c.getAutoCommit()) {
c.setAutoCommit(false);
}
} catch (SQLException e) {
throw new JenaException("Transaction begin failed: ", e);
}
} else {
notSupported("begin transaction");
}
}
public void abort() {
if (transactionsSupported()) {
try {
Connection c = graph.getConnection();
c.rollback();
c.commit();
c.setAutoCommit(true);
} catch (SQLException e) {
throw new JenaException("Transaction rollback failed: ", e);
}
} else {
notSupported("abort transaction");
}
}
public void commit() {
if (transactionsSupported()) {
try {
Connection c = graph.getConnection();
c.commit();
c.setAutoCommit(true);
} catch (SQLException e) {
throw new JenaException("Transaction commit failed: ", e);
}
} else {
notSupported("commit transaction");
}
}
private void notSupported(String opName) {
throw new UnsupportedOperationException(opName);
}
}