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Commons DBCP example source code file (

This example Commons DBCP source code file ( is included in the "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Commons DBCP tags/keywords

connection, jdbc, map, nullpointerexception, nullpointerexception, sql, sqlexception, sqlexception, transaction, transaction, transactioncontext, transactioncontext, transactionregistry, unable, util, weakhashmap, xaresource, xaresource

The Commons DBCP source code

 * 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
 *  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.apache.commons.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) {

Other Commons DBCP examples (source code examples)

Here is a short list of links related to this Commons DBCP source code file:

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