/**
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.datanucleus.store.rdbms.datasource.dbcp.managed;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Map;
import java.util.WeakHashMap;
import javax.transaction.Status;
import javax.transaction.SystemException;
import javax.transaction.Transaction;
import javax.transaction.TransactionManager;
import javax.transaction.xa.XAResource;
/**
* TransactionRegistry tracks Connections and XAResources in a transacted environment for a single XAConnectionFactory.
* </p>
* The TransactionRegistry hides the details of transaction processing from the existing DBCP pooling code, and gives
* the ManagedConnection a way to enlist connections in a transaction, allowing for the maximal rescue of DBCP.
*
* @author Dain Sundstrom
* @version $Revision$
*/
public class TransactionRegistry {
private final TransactionManager transactionManager;
private final Map caches = new WeakHashMap();
private final Map xaResources = new WeakHashMap();
/**
* Creates a TransactionRegistry for the specified transaction manager.
* @param transactionManager the transaction manager used to enlist connections
*/
public TransactionRegistry(TransactionManager transactionManager) {
this.transactionManager = transactionManager;
}
/**
* Registers the association between a Connection and a XAResource. When a connection
* is enlisted in a transaction, it is actually the XAResource that is given to the transaction
* manager.
*
* @param connection the JDBC connection
* @param xaResource the XAResource which managed the connection within a transaction
*/
public synchronized void registerConnection(Connection connection, XAResource xaResource) {
if (connection == null) throw new NullPointerException("connection is null");
if (xaResource == null) throw new NullPointerException("xaResource is null");
xaResources.put(connection, xaResource);
}
/**
* Gets the XAResource registered for the connection.
* @param connection the connection
* @return the XAResource registered for the connection; never null
* @throws SQLException if the connection does not have a registered XAResource
*/
public synchronized XAResource getXAResource(Connection connection) throws SQLException {
if (connection == null) throw new NullPointerException("connection is null");
XAResource xaResource = (XAResource) xaResources.get(connection);
if (xaResource == null) {
throw new SQLException("Connection does not have a registered XAResource " + connection);
}
return xaResource;
}
/**
* Gets the active TransactionContext or null if not Transaction is active.
* @return the active TransactionContext or null if not Transaction is active
* @throws SQLException if an error occurs while fetching the transaction
*/
public TransactionContext getActiveTransactionContext() throws SQLException {
Transaction transaction = null;
try {
transaction = transactionManager.getTransaction();
// was there a transaction?
if (transaction == null) {
return null;
}
// is it active
int status = transaction.getStatus();
if (status != Status.STATUS_ACTIVE && status != Status.STATUS_MARKED_ROLLBACK) {
return null;
}
} catch (SystemException e) {
throw (SQLException) new SQLException("Unable to determine current transaction ").initCause(e);
}
// register the the context (or create a new one)
synchronized (this) {
TransactionContext cache = (TransactionContext) caches.get(transaction);
if (cache == null) {
cache = new TransactionContext(this, transaction);
caches.put(transaction, cache);
}
return cache;
}
}
/**
* Unregisters a destroyed connection from {@link TransactionRegistry}
* @param connection
*/
public synchronized void unregisterConnection(Connection connection) {
xaResources.remove(connection);
}
}