/**
* Redistribution and use of this software and associated documentation
* ("Software"), with or without modification, are permitted provided
* that the following conditions are met:
*
* 1. Redistributions of source code must retain copyright
* statements and notices. Redistributions must also contain a
* copy of this document.
*
* 2. Redistributions in binary form must reproduce the
* above copyright notice, this list of conditions and the
* following disclaimer in the documentation and/or other
* materials provided with the distribution.
*
* 3. The name "Exolab" must not be used to endorse or promote
* products derived from this Software without prior written
* permission of Exoffice Technologies. For written permission,
* please contact info@exolab.org.
*
* 4. Products derived from this Software may not be called "Exolab"
* nor may "Exolab" appear in their names without prior written
* permission of Exoffice Technologies. Exolab is a registered
* trademark of Exoffice Technologies.
*
* 5. Due credit should be given to the Exolab Project
* (http://www.exolab.org/).
*
* THIS SOFTWARE IS PROVIDED BY EXOFFICE TECHNOLOGIES AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
* NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* EXOFFICE TECHNOLOGIES OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Copyright 2001-2004 (C) Exoffice Technologies Inc. All Rights Reserved.
*
* $Id: DatabaseService.java,v 1.4 2006/02/23 11:17:39 tanderson Exp $
*/
package org.exolab.jms.persistence;
import java.sql.Connection;
import java.sql.SQLException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.exolab.jms.common.threads.ThreadListener;
import org.exolab.jms.config.Configuration;
import org.exolab.jms.config.DatabaseConfiguration;
import org.exolab.jms.config.RdbmsDatabaseConfiguration;
import org.exolab.jms.service.Service;
import org.exolab.jms.service.ServiceException;
import org.exolab.jms.service.ServiceThreadListener;
/**
* The DatabaseService is used for managing the persistence aspect of this
* project.
*
* @author <a href="mailto:jima@comware.com.au">Jim Alateras</a>
* @version $Revision: 1.4 $ $Date: 2006/02/23 11:17:39 $
*/
public class DatabaseService extends Service {
/**
* The configuration.
*/
private final DatabaseConfiguration _config;
/**
* The persistence adapter.
*/
private PersistenceAdapter _adapter;
/**
* Thread listener.
*/
private ServiceThreadListener _listener;
/**
* State monitor.
*/
private ThreadListener _monitor;
/**
* The service state associated with the current thread.
*/
private static final ThreadLocal _state = new ThreadLocal();
/**
* The logger.
*/
private static final Log _log = LogFactory.getLog(DatabaseService.class);
/**
* Construct a new <code>DatabaseService</code>.
*
* @param config the configuration
*/
public DatabaseService(Configuration config) {
super("DatabaseService");
_config = config.getDatabaseConfiguration();
_monitor = new Monitor();
}
/**
* Sets the service thread listener.
*
* @param listener the service thread listener
*/
public void setServiceThreadListener(ServiceThreadListener listener) {
_listener = listener;
}
/**
* Returns the database service associated with the current thread.
*
* @return the database service associated with the current thread
* @throws PersistenceException if no instance is registered
*/
public static DatabaseService getInstance() throws PersistenceException {
State state = (State) _state.get();
if (state == null) {
throw new PersistenceException("No DatabaseService registered");
}
return state.getInstance();
}
/**
* Returns the {@link PersistenceAdapter} created by this service.
*
* @return the persistence adapter
*/
public PersistenceAdapter getAdapter() {
return _adapter;
}
/**
* Begin a transaction.
*
* @throws PersistenceException if a transaction cannot be started
*/
public void begin() throws PersistenceException {
State state = (State) _state.get();
if (state == null) {
_state.set(new State());
} else {
if (state.getInstance() != this) {
throw new PersistenceException(
"State not associated with current service");
}
_log.error("Transaction in progress, allocated at ", state.STACK);
throw new PersistenceException("Transaction already in progress");
}
}
/**
* Returns the connection associated with the current thread.
*
* @return the connection associated with the current thread
* @throws PersistenceException if no connection is associated
*/
public Connection getConnection() throws PersistenceException {
State state = getState();
if (state.getConnection() == null) {
state.setConnection(_adapter.getConnection());
}
return state.getConnection();
}
/**
* Commit the current transaction.
*
* @throws PersistenceException if the transaction can't be committed
*/
public void commit() throws PersistenceException {
State state = getState();
Connection connection = state.getConnection();
try {
if (connection != null) {
connection.commit();
}
} catch (SQLException exception) {
throw new PersistenceException("Failed to commit", exception);
} finally {
SQLHelper.close(connection);
_state.set(null);
}
}
/**
* Rollback the current transaction.
*
* @throws PersistenceException if the transaction can't be rolled back
*/
public void rollback() throws PersistenceException {
State state = getState();
Connection connection = state.getConnection();
try {
if (connection != null) {
connection.rollback();
}
} catch (SQLException exception) {
throw new PersistenceException("Failed to rollback", exception);
} finally {
SQLHelper.close(connection);
_state.set(null);
}
}
/**
* Determines if a transaction is in progress.
*
* @return <code>true</code> if a transaction is in progress; otherwise
* <code>false</code>
*/
public boolean isTransacted() {
return (_state.get() != null);
}
/**
* Start the service.
*
* @throws ServiceException if the service fails to start
*/
protected void doStart() throws ServiceException {
if (_listener != null) {
_listener.addThreadListener(_monitor);
} else {
_log.info("Not monitoring service threads");
}
_adapter = createAdapter(_config);
// remove the expired messages
try {
begin();
Connection connection = getConnection();
getAdapter().removeExpiredMessages(connection);
_log.info("Removed expired messages.");
commit();
} catch (PersistenceException exception) {
try {
rollback();
} catch (PersistenceException ignore) {
// no-op
}
throw exception;
} catch (Exception exception) {
// rethrow as an appropriate exception
throw new ServiceException("Failed to start the DatabaseService",
exception);
}
}
/**
* Stop the service.
*
* @throws ServiceException if the service fails to stop
*/
protected void doStop() throws ServiceException {
if (_listener != null) {
_listener.removeThreadListener(_monitor);
}
_adapter.close();
_state.set(null);
}
/**
* Returns the current transaction state.
*
* @return the current transaction state
* @throws PersistenceException if there is no current transaction
*/
private State getState() throws PersistenceException {
State state = (State) _state.get();
if (state == null) {
throw new PersistenceException("No transaction in progress");
}
if (state.getInstance() != this) {
throw new PersistenceException(
"State not associated with current service");
}
return state;
}
/**
* Create an instance of an persistence adapter using the specified database
* configuration.
*
* @param dbConfig database configuration
* @return the created adapter
* @throws PersistenceException if the adapter cant be created
*/
private PersistenceAdapter createAdapter(
DatabaseConfiguration dbConfig) throws PersistenceException {
PersistenceAdapter adapter = null;
RdbmsDatabaseConfiguration
config = dbConfig.getRdbmsDatabaseConfiguration();
_log.info("Creating RdbmsAdapter for "
+ config.getDriver());
adapter = new RDBMSAdapter(dbConfig, config.getDriver(),
config.getUrl(),
config.getUser(),
config.getPassword());
return adapter;
}
class State {
public final Exception STACK = new Exception();
private Connection _connection;
public DatabaseService getInstance() {
return DatabaseService.this;
}
public Connection getConnection() {
return _connection;
}
public void setConnection(Connection connection) {
_connection = connection;
}
}
static class Monitor implements ThreadListener {
public void begin(Runnable command) {
}
public void end(Runnable command) {
State state = (State) _state.get();
if (state != null) {
_state.set(null);
_log.error("Transaction not finished by " + command
+ ". Allocated at ", state.STACK);
SQLHelper.close(state.getConnection());
}
}
}
}