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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 2000-2010 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
 * or packager/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 *
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at packager/legal/LICENSE.txt.
 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
 * exception as provided by Oracle in the GPL Version 2 section of the License
 * file that accompanied this code.
 *
 * Modifications:
 * If applicable, add the following below the License Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
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 * Contributor(s):
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
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 * recipient has the option to distribute your version of this file under
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 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */

/*
 * @(#)TransactionDAOImpl.java	1.34 08/13/07
 */ 

package com.sun.messaging.jmq.jmsserver.persist.jdbc;

import com.sun.messaging.jmq.util.log.Logger;
import com.sun.messaging.jmq.util.JMQXid;
import com.sun.messaging.jmq.jmsserver.util.*;
import com.sun.messaging.jmq.jmsserver.data.TransactionState;
import com.sun.messaging.jmq.jmsserver.data.TransactionUID;
import com.sun.messaging.jmq.jmsserver.data.TransactionBroker;
import com.sun.messaging.jmq.jmsserver.resources.*;
import com.sun.messaging.jmq.jmsserver.persist.TransactionInfo;
import com.sun.messaging.jmq.jmsserver.persist.HABrokerInfo;
import com.sun.messaging.jmq.jmsserver.core.BrokerAddress;
import com.sun.messaging.jmq.jmsserver.Globals;
import com.sun.messaging.jmq.io.Status;

import java.util.*;
import java.sql.*;
import java.io.IOException;

/**
 * This class implement a generic TransactionDAO.
 */
class TransactionDAOImpl extends BaseDAOImpl implements TransactionDAO {

    protected String tableName;

    // SQLs
    protected String insertSQL;
    protected String updateTxnStateSQL;
    protected String updateTxnHomeBrokerSQL;
    protected String updateTxnBrokersSQL;
    protected String updateAccessedTimeSQL;
    protected String deleteSQL;
    protected String deleteNotInStateSQL;
    protected String selectTxnStateSQL;
    protected String selectTxnHomeBrokerSQL;
    protected String selectTxnBrokersSQL;
    protected String selectAccessedTimeSQL;
    protected String selectTxnInfoSQL;
    protected String selectTxnStatesByBrokerSQL;
    protected String selectTxnStatesByBrokerAndTypeSQL;
    protected String selectRemoteTxnStatesByBrokerAndTypeSQL;
    protected String selectUsageInfoSQL;


    /**
     * Constructor
     * @throws BrokerException
     */
    TransactionDAOImpl() throws BrokerException {

        // Initialize all SQLs
        DBManager dbMgr = DBManager.getDBManager();

        // Criteria to ensure the local broker still owns the store for HA
        String brokerNotTakenOverClause = Globals.getHAEnabled() ?
            " AND NOT EXISTS (" +
            ((BrokerDAOImpl)dbMgr.getDAOFactory().getBrokerDAO())
                .selectIsBeingTakenOverSQL + ")" : "";

        tableName = dbMgr.getTableName( TABLE_NAME_PREFIX );

        insertSQL = new StringBuffer(128)
            .append( "INSERT INTO " ).append( tableName )
            .append( " ( " )
            .append( ID_COLUMN ).append( ", " )
            .append( TYPE_COLUMN ).append( ", " )
            .append( STATE_COLUMN ).append( ", " )
            .append( AUTO_ROLLBACK_COLUMN ).append( ", " )
            .append( XID_COLUMN ).append( ", " )
            .append( TXN_STATE_COLUMN ).append( ", " )
            .append( TXN_HOME_BROKER_COLUMN ).append( ", " )
            .append( TXN_BROKERS_COLUMN ).append( ", " )
            .append( STORE_SESSION_ID_COLUMN ).append( ", " )
            .append( EXPIRED_TS_COLUMN ).append( ", " )
            .append( ACCESSED_TS_COLUMN )
            .append( ") VALUES ( ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ? )" )
            .toString();

        updateTxnStateSQL = new StringBuffer(128)
            .append( "UPDATE " ).append( tableName )
            .append( " SET " )
            .append( STATE_COLUMN ).append( " = ?, " )
            .append( TXN_STATE_COLUMN ).append( " = ?" )
            .append( " WHERE " )
            .append( ID_COLUMN ).append( " = ?" )
            .append( brokerNotTakenOverClause )
            .toString();

        updateTxnHomeBrokerSQL = new StringBuffer(128)
            .append( "UPDATE " ).append( tableName )
            .append( " SET " )
            .append( TXN_HOME_BROKER_COLUMN ).append( " = ?" )
            .append( " WHERE " )
            .append( ID_COLUMN ).append( " = ?" )
            .append( brokerNotTakenOverClause )
            .toString();

        updateTxnBrokersSQL = new StringBuffer(128)
            .append( "UPDATE " ).append( tableName )
            .append( " SET " )
            .append( TYPE_COLUMN ).append( " = ?, " )
            .append( TXN_BROKERS_COLUMN ).append( " = ?" )
            .append( " WHERE " )
            .append( ID_COLUMN ).append( " = ?" )
            .append( brokerNotTakenOverClause )
            .toString();

        updateAccessedTimeSQL = new StringBuffer(128)
            .append( "UPDATE " ).append( tableName )
            .append( " SET " )
            .append( ACCESSED_TS_COLUMN ).append( " = ?" )
            .append( " WHERE " )
            .append( ID_COLUMN ).append( " = ?" )
            .toString();

        deleteSQL = new StringBuffer(128)
            .append( "DELETE FROM " ).append( tableName )
            .append( " WHERE " )
            .append( ID_COLUMN ).append( " = ?" )
            .toString();

        deleteNotInStateSQL = new StringBuffer(128)
            .append( "DELETE FROM " ).append( tableName )
            .append( " WHERE " )
            .append( STATE_COLUMN ).append( " <> ?" )
            .toString();

        selectTxnStateSQL = new StringBuffer(128)
            .append( "SELECT " )
            .append( STATE_COLUMN ).append( ", " )
            .append( TXN_STATE_COLUMN )
            .append( " FROM " ).append( tableName )
            .append( " WHERE " )
            .append( ID_COLUMN ).append( " = ?" )
            .toString();

        selectTxnHomeBrokerSQL = new StringBuffer(128)
            .append( "SELECT " )
            .append( TXN_HOME_BROKER_COLUMN )
            .append( " FROM " ).append( tableName )
            .append( " WHERE " )
            .append( ID_COLUMN ).append( " = ?" )
            .toString();

        selectTxnBrokersSQL = new StringBuffer(128)
            .append( "SELECT " )
            .append( TXN_BROKERS_COLUMN ).append( ", " )
            .append( STATE_COLUMN )
            .append( " FROM " ).append( tableName )
            .append( " WHERE " )
            .append( ID_COLUMN ).append( " = ?" )
            .toString();

        selectAccessedTimeSQL = new StringBuffer(128)
            .append( "SELECT " )
            .append( ACCESSED_TS_COLUMN )
            .append( " FROM " ).append( tableName )
            .append( " WHERE " )
            .append( ID_COLUMN ).append( " = ?" )
            .toString();

        selectTxnInfoSQL = new StringBuffer(128)
            .append( "SELECT " )
            .append( TYPE_COLUMN ).append( ", " )
            .append( STATE_COLUMN ).append( ", " )
            .append( TXN_STATE_COLUMN ).append( ", " )
            .append( TXN_HOME_BROKER_COLUMN ).append( ", " )
            .append( TXN_BROKERS_COLUMN )
            .append( " FROM " ).append( tableName )
            .append( " WHERE " )
            .append( ID_COLUMN ).append( " = ?" )
            .toString();

        selectTxnStatesByBrokerSQL = new StringBuffer(128)
            .append( "SELECT txnTbl." )
            .append( ID_COLUMN ).append( ", " )
            .append( TYPE_COLUMN ).append(", " )
            .append( STATE_COLUMN ).append( ", " )
            .append( TXN_STATE_COLUMN ).append( ", " )
            .append( TXN_BROKERS_COLUMN )
            .append( " FROM " ).append( tableName ).append( " txnTbl, " )
            .append(   dbMgr.getTableName( StoreSessionDAO.TABLE_NAME_PREFIX ) )
            .append(   " sesTbl" )
            .append( " WHERE sesTbl." )
            .append(   StoreSessionDAO.BROKER_ID_COLUMN ).append( " = ?" )
            .append( " AND sesTbl." ).append( StoreSessionDAO.ID_COLUMN )
            .append(   " = txnTbl." ).append( STORE_SESSION_ID_COLUMN )
            .append( " AND " )
            .append(  STATE_COLUMN ).append( " <> -1" )
            .append( " AND " )
            .append(  TYPE_COLUMN ).append( " IN (" )
            .append(  TransactionInfo.TXN_LOCAL ).append( ", " )
            .append(  TransactionInfo.TXN_CLUSTER ).append( ")" )
            .toString();

        selectTxnStatesByBrokerAndTypeSQL = new StringBuffer(128)
            .append( "SELECT txnTbl." )
            .append( ID_COLUMN ).append( ", " )
            .append( STATE_COLUMN ).append( ", " )
            .append( TXN_STATE_COLUMN )
            .append( " FROM " ).append( tableName ).append( " txnTbl, " )
            .append(   dbMgr.getTableName( StoreSessionDAO.TABLE_NAME_PREFIX ) )
            .append(   " sesTbl" )
            .append( " WHERE sesTbl." )
            .append(   StoreSessionDAO.BROKER_ID_COLUMN ).append( " = ?" )
            .append( " AND sesTbl." ).append( StoreSessionDAO.ID_COLUMN )
            .append(   " = txnTbl." ).append( STORE_SESSION_ID_COLUMN )
            .append( " AND " )
            .append( STATE_COLUMN ).append( " <> -1" )
            .append( " AND " )
            .append( TYPE_COLUMN ).append( " = ?" )
            .toString();

        /*
         * Cannot specify a LOB column in a SELECT...DISTINCT so use subquery
         */
        selectRemoteTxnStatesByBrokerAndTypeSQL = new StringBuffer(256)
            .append( "SELECT " )
            .append( ID_COLUMN ).append( ", " )
            .append( STATE_COLUMN ).append( ", " )
            .append( TXN_STATE_COLUMN )
            .append( " FROM " )
            .append( tableName )
            .append( " WHERE " )
            .append( TYPE_COLUMN ).append( " = ?" )
            .append( " AND " )
            .append( STORE_SESSION_ID_COLUMN )
            .append( " NOT IN (SELECT " ).append( StoreSessionDAO.ID_COLUMN )
            .append( " FROM ")
            .append(   dbMgr.getTableName( StoreSessionDAO.TABLE_NAME_PREFIX ) )
            .append( " WHERE ")
            .append(   StoreSessionDAO.BROKER_ID_COLUMN ).append( " = ?)" )
            .append( " AND " )
            .append( ID_COLUMN )
            .append( " IN (SELECT DISTINCT c." )
            .append( ConsumerStateDAO.TRANSACTION_ID_COLUMN )
            .append( " FROM " )
            .append(   dbMgr.getTableName( StoreSessionDAO.TABLE_NAME_PREFIX ) )
            .append(   " s, " )
            .append(   dbMgr.getTableName( MessageDAO.TABLE_NAME_PREFIX ) )
            .append(   " m, " )
            .append(   dbMgr.getTableName( ConsumerStateDAO.TABLE_NAME_PREFIX ) )
            .append(   " c" )
            .append( " WHERE s." )
            .append(   StoreSessionDAO.BROKER_ID_COLUMN ).append( " = ?" )
            .append( " AND s." ).append( StoreSessionDAO.ID_COLUMN )
            .append(   " = m." ).append( MessageDAO.STORE_SESSION_ID_COLUMN )
            .append( " AND m." ).append( MessageDAO.ID_COLUMN )
            .append(   " = c." ).append( ConsumerStateDAO.MESSAGE_ID_COLUMN )
            .append( " AND c." ).append( ConsumerStateDAO.TRANSACTION_ID_COLUMN )
            .append(   " IS NOT NULL)" )
            .toString();

        selectUsageInfoSQL = new StringBuffer(128)
            .append( "SELECT MAX(mcount), MAX(scount) FROM (" )
            .append(    "SELECT COUNT(*) AS mcount, 0 AS scount FROM " )
            .append(    dbMgr.getTableName( MessageDAO.TABLE_NAME_PREFIX ) )
            .append(    " WHERE " )
            .append(    MessageDAO.TRANSACTION_ID_COLUMN ).append( " = ?" )
            .append( " UNION " )
            .append(    "SELECT 0 AS mcount, COUNT(*) AS scount FROM " )
            .append(    dbMgr.getTableName( ConsumerStateDAO.TABLE_NAME_PREFIX ) )
            .append(    " WHERE " )
            .append(    ConsumerStateDAO.TRANSACTION_ID_COLUMN ).append( " = ?" )
            .append( ")" )
            .toString();
    }

    /**
     * Get the prefix name of the table.
     * @return table name
     */
    public final String getTableNamePrefix() {
        return TABLE_NAME_PREFIX;
    }

    /**
     * Get the name of the table.
     * @return table name
     */
    public String getTableName() {
        return tableName;
    }

    /**
     * Insert a new entry.
     * @param conn database connection
     * @param txnUID the transaction ID
     * @param txnState the TransactionState
     * @param storeSessionID the store session ID
     * @throws BrokerException
     */
    public void insert( Connection conn, TransactionUID txnUID,
        TransactionState txnState, long storeSessionID )
        throws BrokerException {

        insert( conn, txnUID, txnState, null, null, TransactionInfo.TXN_LOCAL,
            storeSessionID );
    }

    /**
     * Insert a new entry.
     * @param conn database connection
     * @param txnUID the transaction ID
     * @param txnState the TransactionState
     * @param txnHomeBroker the home broker for a REMOTE txn
     * @param txnBrokers the participant brokers for a REMOTE/CLUSTER txn
     * @param storeSessionID the store session ID
     * @throws BrokerException
     */
    public void insert( Connection conn, TransactionUID txnUID,
        TransactionState txnState, BrokerAddress txnHomeBroker,
        TransactionBroker[] txnBrokers, int type, long storeSessionID )
        throws BrokerException {

        long id = txnUID.longValue();

        boolean myConn = false;
        PreparedStatement pstmt = null;
        Exception myex = null;
        try {
            // Get a connection
            DBManager dbMgr = DBManager.getDBManager();
            if ( conn == null ) {
                conn = dbMgr.getConnection( true );
                myConn = true;
            }

            try {
                pstmt = conn.prepareStatement( insertSQL );
                pstmt.setLong( 1, id );
                pstmt.setInt( 2, type );
                pstmt.setInt( 3, txnState.getState() );
                pstmt.setInt( 4, txnState.getType().intValue() );

                JMQXid jmqXid = txnState.getXid();
                if ( jmqXid != null ) {
                    pstmt.setString( 5, jmqXid.toString() );
                } else {
                    pstmt.setNull( 5, Types.VARCHAR );
                }

                Util.setObject( pstmt, 6, txnState );
                Util.setObject( pstmt, 7, txnHomeBroker );
                Util.setObject( pstmt, 8, txnBrokers );

                pstmt.setLong( 9, storeSessionID );
                pstmt.setLong( 10, txnState.getExpirationTime() );
                pstmt.setLong( 11, txnState.getLastAccessTime() );
                pstmt.executeUpdate();
            } catch ( Exception e ) {
                myex = e;
                try {
                    if ( (conn != null) && !conn.getAutoCommit() ) {
                        conn.rollback();
                    }
                } catch ( SQLException rbe ) {
                    logger.log( Logger.ERROR, BrokerResources.X_DB_ROLLBACK_FAILED, rbe );
                }

                try {
                    // We check for the existence of the txn here instead of
                    // doing it before the INSERT stmt for performance, i.e.
                    // the chance of inserting duplicate record is very small
                    if ( hasTransaction( conn, id) ) {
                        throw new BrokerException(
                            br.getKString( BrokerResources.E_TRANSACTIONID_EXISTS_IN_STORE,
                            txnUID.toString() ) );
                    }
                } catch ( Exception e2 ) {
                    // Ignore this exception so orig exception can be thrown!
                    logger.log( Logger.ERROR, br.getKString(
                        BrokerResources.X_INTERNAL_EXCEPTION,
                        "Checking existence of txn" + txnUID ), e2 );
                }

                Exception ex;
                if ( e instanceof BrokerException ) {
                    throw (BrokerException)e;
                } else if ( e instanceof IOException ) {
                    ex = DBManager.wrapIOException("[" + insertSQL + "]", (IOException)e);
                } else if ( e instanceof SQLException ) {
                    ex = DBManager.wrapSQLException("[" + insertSQL + "]", (SQLException)e);
                } else {
                    ex = e;
                }

                throw new BrokerException(
                    br.getKString( BrokerResources.X_PERSIST_TRANSACTION_FAILED,
                    txnUID ), ex );
            }
        } catch (BrokerException e) {
            myex = e;
            throw e;
        } finally {
            if ( myConn ) {
                Util.close( null, pstmt, conn, myex );
            } else {
                Util.close( null, pstmt, null, myex );
            }
        }
    }

    /**
     * Update the TransactionState for the specified transaction.
     * @param conn database connection
     * @param txnUID the transaction ID
     * @param txnState the new state
     * @throws BrokerException if transaction does not exists in the store
     */
    public void updateTransactionState( Connection conn, TransactionUID txnUID,
        TransactionState txnState ) throws BrokerException {

        boolean myConn = false;
        PreparedStatement pstmt = null;
        Exception myex = null;
        try {
            // Get a connection
            DBManager dbMgr = DBManager.getDBManager();
            if ( conn == null ) {
                conn = dbMgr.getConnection( true );
                myConn = true;
            }

            pstmt = conn.prepareStatement( updateTxnStateSQL );
            pstmt.setInt( 1, txnState.getState() );
            Util.setObject( pstmt, 2, txnState );
            pstmt.setLong( 3, txnUID.longValue() );

            if ( Globals.getHAEnabled() ) {
                pstmt.setString( 4, dbMgr.getBrokerID() );
            }

            if ( pstmt.executeUpdate() == 0 ) {
                // For HA mode, check if this broker still owns the store
                if ( Globals.getHAEnabled() ) {
                    String brokerID = dbMgr.getBrokerID();
                    BrokerDAO dao = dbMgr.getDAOFactory().getBrokerDAO();
                    if ( dao.isBeingTakenOver( conn, brokerID ) ) {
                        BrokerException be = new StoreBeingTakenOverException(
                            br.getKString( BrokerResources.E_STORE_BEING_TAKEN_OVER ) );

                        try {
                            HABrokerInfo bkrInfo = dao.getBrokerInfo( conn, brokerID );
                            logger.log( Logger.ERROR, br.getKString(
                                BrokerResources.X_INTERNAL_EXCEPTION,
                                bkrInfo.toString() ), be );
                        } catch (Throwable t) { /* Ignore error */ }

                        throw be;
                    }
                }

                throw new BrokerException(
                    br.getKString( BrokerResources.E_TRANSACTIONID_NOT_FOUND_IN_STORE,
                    txnUID ), Status.NOT_FOUND );
            }
        } catch ( Exception e ) {
            myex = e;
            try {
                if ( (conn != null) && !conn.getAutoCommit() ) {
                    conn.rollback();
                }
            } catch ( SQLException rbe ) {
                logger.log( Logger.ERROR, BrokerResources.X_DB_ROLLBACK_FAILED, rbe );
            }

            Exception ex;
            if ( e instanceof BrokerException ) {
                throw (BrokerException)e;
            } else if ( e instanceof IOException ) {
                ex = DBManager.wrapIOException("[" + updateTxnStateSQL + "]", (IOException)e);
            } else if ( e instanceof SQLException ) {
                ex = DBManager.wrapSQLException("[" + updateTxnStateSQL + "]", (SQLException)e);
            } else {
                ex = e;
            }
            throw new BrokerException(
                br.getKString( BrokerResources.X_UPDATE_TXNSTATE_FAILED,
                txnUID ), ex );
        } finally {
            if ( myConn ) {
                Util.close( null, pstmt, conn, myex );
            } else {
                Util.close( null, pstmt, null, myex );
            }
        }
    }

    /**
     * Update the transaction home broker for the specified transaction.
     * @param conn database connection
     * @param txnUID the transaction ID
     * @param txnHomeBroker the home broker for a REMOTE txn
     * @throws BrokerException if transaction does not exists in the store
     */
    public void updateTransactionHomeBroker( Connection conn, TransactionUID txnUID,
        BrokerAddress txnHomeBroker) throws BrokerException {

        boolean myConn = false;
        PreparedStatement pstmt = null;
        Exception myex = null;
        try {
            // Get a connection
            DBManager dbMgr = DBManager.getDBManager();
            if ( conn == null ) {
                conn = dbMgr.getConnection( true );
                myConn = true;
            }

            pstmt = conn.prepareStatement( updateTxnHomeBrokerSQL );
            Util.setObject( pstmt, 1, txnHomeBroker );
            pstmt.setLong( 2, txnUID.longValue() );

            if ( Globals.getHAEnabled() ) {
                pstmt.setString( 3, dbMgr.getBrokerID() );
            }

            if ( pstmt.executeUpdate() == 0 ) {
                // For HA mode, check if this broker still owns the store
                if ( Globals.getHAEnabled() ) {
                    String brokerID = dbMgr.getBrokerID();
                    BrokerDAO dao = dbMgr.getDAOFactory().getBrokerDAO();
                    if ( dao.isBeingTakenOver( conn, brokerID ) ) {
                        BrokerException be = new StoreBeingTakenOverException(
                            br.getKString( BrokerResources.E_STORE_BEING_TAKEN_OVER ) );

                        try {
                            HABrokerInfo bkrInfo = dao.getBrokerInfo( conn, brokerID );
                            logger.log( Logger.ERROR, br.getKString(
                                BrokerResources.X_INTERNAL_EXCEPTION,
                                bkrInfo.toString() ), be );
                        } catch (Throwable t) { /* Ignore error */ }

                        throw be;
                    }
                }

                throw new BrokerException(
                    br.getKString( BrokerResources.E_TRANSACTIONID_NOT_FOUND_IN_STORE,
                    txnUID ), Status.NOT_FOUND );
            }
        } catch ( Exception e ) {
            myex = e;
            try {
                if ( (conn != null) && !conn.getAutoCommit() ) {
                    conn.rollback();
                }
            } catch ( SQLException rbe ) {
                logger.log( Logger.ERROR, BrokerResources.X_DB_ROLLBACK_FAILED, rbe );
            }

            Exception ex;
            if ( e instanceof BrokerException ) {
                throw (BrokerException)e;
            } else if ( e instanceof IOException ) {
                ex = DBManager.wrapIOException("[" + updateTxnHomeBrokerSQL + "]", (IOException)e);
            } else if ( e instanceof SQLException ) {
                ex = DBManager.wrapSQLException("[" + updateTxnHomeBrokerSQL + "]", (SQLException)e);
            } else {
                ex = e;
            }
            throw new BrokerException(
                br.getKString( BrokerResources.X_PERSIST_TRANSACTION_FAILED,
                txnUID ), ex );
        } finally {
            if ( myConn ) {
                Util.close( null, pstmt, conn, myex );
            } else {
                Util.close( null, pstmt, null, myex );
            }
        }
    }

    /**
     * Update transaction's participant brokers for the specified transaction.
     * @param conn database connection
     * @param txnUID the transaction ID
     * @param txnBrokers the transaction's participant brokers
     * @throws BrokerException if transaction does not exists in the store
     */
    public void updateTransactionBrokers( Connection conn, TransactionUID txnUID,
        TransactionBroker[] txnBrokers ) throws BrokerException {

        boolean myConn = false;
        PreparedStatement pstmt = null;
        Exception myex = null;
        try {
            // Get a connection
            DBManager dbMgr = DBManager.getDBManager();
            if ( conn == null ) {
                conn = dbMgr.getConnection( true );
                myConn = true;
            }

            pstmt = conn.prepareStatement( updateTxnBrokersSQL );
            pstmt.setInt( 1, TransactionInfo.TXN_CLUSTER );
            Util.setObject( pstmt, 2, txnBrokers );
            pstmt.setLong( 3, txnUID.longValue() );

            if ( Globals.getHAEnabled() ) {
                pstmt.setString( 4, dbMgr.getBrokerID() );
            }

            if ( pstmt.executeUpdate() == 0 ) {
                // For HA mode, check if this broker still owns the store
                if ( Globals.getHAEnabled() ) {
                    String brokerID = dbMgr.getBrokerID();
                    BrokerDAO dao = dbMgr.getDAOFactory().getBrokerDAO();
                    if ( dao.isBeingTakenOver( conn, brokerID ) ) {
                        BrokerException be = new StoreBeingTakenOverException(
                            br.getKString( BrokerResources.E_STORE_BEING_TAKEN_OVER ) );

                        try {
                            HABrokerInfo bkrInfo = dao.getBrokerInfo( conn, brokerID );
                            logger.log( Logger.ERROR, br.getKString(
                                BrokerResources.X_INTERNAL_EXCEPTION,
                                bkrInfo.toString() ), be );
                        } catch (Throwable t) { /* Ignore error */ }

                        throw be;
                    }
                }

                throw new BrokerException(
                    br.getKString( BrokerResources.E_TRANSACTIONID_NOT_FOUND_IN_STORE,
                    txnUID ), Status.NOT_FOUND );
            }
        } catch ( Exception e ) {
            myex = e;
            try {
                if ( (conn != null) && !conn.getAutoCommit() ) {
                    conn.rollback();
                }
            } catch ( SQLException rbe ) {
                logger.log( Logger.ERROR, BrokerResources.X_DB_ROLLBACK_FAILED, rbe );
            }

            Exception ex;
            if ( e instanceof BrokerException ) {
                throw (BrokerException)e;
            } else if ( e instanceof IOException ) {
                ex = DBManager.wrapIOException("[" + updateTxnBrokersSQL + "]", (IOException)e);
            } else if ( e instanceof SQLException ) {
                ex = DBManager.wrapSQLException("[" + updateTxnBrokersSQL + "]", (SQLException)e);
            } else {
                ex = e;
            }
            throw new BrokerException(
                br.getKString( BrokerResources.X_PERSIST_TRANSACTION_FAILED,
                txnUID ), ex );
        } finally {
            if ( myConn ) {
                Util.close( null, pstmt, conn, myex );
            } else {
                Util.close( null, pstmt, null, myex );
            }
        }
    }

    /**
     * Update transaction's participant broker state if the txn's state
     * matches the expected state.
     * @param conn database connection
     * @param txnUID the transaction ID
     * @param expectedTxnState the expected transaction state
     * @param txnBkr the participant broker to be updated
     * @throws BrokerException if transaction does not exists in the store
     */
    public void updateTransactionBrokerState( Connection conn, TransactionUID txnUID,
        int expectedTxnState, TransactionBroker txnBkr) throws BrokerException {

        long id = txnUID.longValue();

        boolean myConn = false;
        PreparedStatement pstmt = null;
        ResultSet rs = null;
        Exception myex = null;
        try {
            // Get a connection
            if ( conn == null ) {
                conn = DBManager.getDBManager().getConnection( false );
                myConn = true;
            }

            // First, retrieve the TransactionBroker array
            int state;
            TransactionBroker[] txnBrokers;

            pstmt = conn.prepareStatement( selectTxnBrokersSQL );
            pstmt.setLong( 1, id );

            rs = pstmt.executeQuery();
            if ( rs.next() ) {
                txnBrokers = (TransactionBroker[])Util.readObject( rs, 1 );
                state = rs.getInt( 2 );
            } else {
                throw new BrokerException(
                    br.getKString( BrokerResources.E_TRANSACTIONID_NOT_FOUND_IN_STORE,
                    txnUID ), Status.NOT_FOUND );
            }

            if ( state != expectedTxnState ) {
                Object[] args = { txnBkr, txnUID,
                    TransactionState.toString(expectedTxnState),
                    TransactionState.toString(state) };
                throw new BrokerException(br.getKString( BrokerResources.E_UPDATE_TXNBROKER_FAILED,
                    args ), Status.CONFLICT);
            }

            // Update the participant broker state
            for ( int i = 0, len = txnBrokers.length; i < len; i++ ) {
                TransactionBroker bkr = txnBrokers[i];
                if ( bkr.equals( txnBkr ) ) {
                    bkr.copyState( txnBkr );
                    break; // done
                }
            }

            // Now update the DB entry
            updateTransactionBrokers( conn, txnUID, txnBrokers );

            // Commit all changes
            if ( myConn ) {
                conn.commit();
            }
        } catch ( Exception e ) {
            myex = e;
            try {
                if ( (conn != null) && !conn.getAutoCommit() ) {
                    conn.rollback();
                }
            } catch ( SQLException rbe ) {
                logger.log( Logger.ERROR, BrokerResources.X_DB_ROLLBACK_FAILED, rbe );
            }

            Exception ex;
            if ( e instanceof BrokerException ) {
                throw (BrokerException)e;
            } else if ( e instanceof IOException ) {
                ex = DBManager.wrapIOException("[" + selectTxnBrokersSQL + "]", (IOException)e);
            } else if ( e instanceof SQLException ) {
                ex = DBManager.wrapSQLException("[" + selectTxnBrokersSQL + "]", (SQLException)e);
            } else {
                ex = e;
            }
            throw new BrokerException(
                br.getKString( BrokerResources.X_PERSIST_TRANSACTION_FAILED,
                txnUID ), ex );
        } finally {
            if ( myConn ) {
                Util.close( rs, pstmt, conn, myex );
            } else {
                Util.close( rs, pstmt, null, myex );
            }
        }
    }

    /**
     * Update the transaction accessed time.
     * @param conn database connection
     * @param txnUID the transaction ID
     * @param accessedTime the new timestamp
     * @throws BrokerException if transaction does not exists in the store
     */
    public void updateAccessedTime( Connection conn, TransactionUID txnUID,
        long accessedTime ) throws BrokerException {

        boolean myConn = false;
        PreparedStatement pstmt = null;
        Exception myex = null;
        try {
            // Get a connection
            if ( conn == null ) {
                conn = DBManager.getDBManager().getConnection( true );
                myConn = true;
            }

            pstmt = conn.prepareStatement( updateAccessedTimeSQL );
            pstmt.setLong( 1, accessedTime );
            pstmt.setLong( 2, txnUID.longValue() );

            if ( pstmt.executeUpdate() == 0 ) {
                throw new BrokerException(
                    br.getKString( BrokerResources.E_TRANSACTIONID_NOT_FOUND_IN_STORE,
                    txnUID ), Status.NOT_FOUND );
            }
        } catch ( Exception e ) {
            myex = e;
            try {
                if ( (conn != null) && !conn.getAutoCommit() ) {
                    conn.rollback();
                }
            } catch ( SQLException rbe ) {
                logger.log( Logger.ERROR, BrokerResources.X_DB_ROLLBACK_FAILED, rbe );
            }

            Exception ex;
            if ( e instanceof BrokerException ) {
                throw (BrokerException)e;
            } else if ( e instanceof SQLException ) {
                ex = DBManager.wrapSQLException("[" + updateAccessedTimeSQL + "]", (SQLException)e);
            } else {
                ex = e;
            }

            throw new BrokerException(
                br.getKString( BrokerResources.X_PERSIST_TRANSACTION_FAILED,
                txnUID ), ex );
        } finally {
            if ( myConn ) {
                Util.close( null, pstmt, conn, myex );
            } else {
                Util.close( null, pstmt, null, myex );
            }
        }
    }

    /**
     * Delete an existing entry.
     * @param conn database connection
     * @param txnUID the transaction ID
     * @throws BrokerException
     */
    public void delete( Connection conn, TransactionUID txnUID )
        throws BrokerException {

        boolean myConn = false;
        PreparedStatement pstmt = null;
        Exception myex = null;
        try {
            // Get a connection
            DBManager dbMgr = DBManager.getDBManager();
            if ( conn == null ) {
                conn = dbMgr.getConnection( false );
                myConn = true;
            }

            pstmt = conn.prepareStatement( deleteSQL );
            pstmt.setLong( 1, txnUID.longValue() );

            if ( pstmt.executeUpdate() == 0 ) {
                throw new BrokerException(
                    br.getKString( BrokerResources.E_TRANSACTIONID_NOT_FOUND_IN_STORE,
                    txnUID ), Status.NOT_FOUND );
            } else {
                // For HA, there is an edge case where msgs is being redelivered
                // after the takeover eventhough the txn has been committed.
                // What happen is the broker has committed the txn but didn't
                // has a chance to ack or deleted the msgs and it crashed.
                // So to be on the safe side, we'll delete all consumer states
                // for this txn when it is committed, i.e. translate to txn is
                // being removed from data store.
                dbMgr.getDAOFactory().getConsumerStateDAO().deleteByTransaction( conn, txnUID );
            }

            // Commit all changes
            if ( myConn ) {
                conn.commit();
            }            
        } catch ( Exception e ) {
            myex = e;
            try {
                if ( (conn != null) && !conn.getAutoCommit() ) {
                    conn.rollback();
                }
            } catch ( SQLException rbe ) {
                logger.log( Logger.ERROR, BrokerResources.X_DB_ROLLBACK_FAILED, rbe );
            }

            Exception ex;
            if ( e instanceof BrokerException ) {
                throw (BrokerException)e;
            } else if ( e instanceof SQLException ) {
                ex = DBManager.wrapSQLException("[" + deleteSQL + "]", (SQLException)e);
            } else {
                ex = e;
            }

            throw new BrokerException(
                br.getKString( BrokerResources.X_REMOVE_TRANSACTION_FAILED,
                txnUID ), ex );
        } finally {
            if ( myConn ) {
                Util.close( null, pstmt, conn, myex );
            } else {
                Util.close( null, pstmt, null, myex );
            }
        }
    }

    /**
     * Delete all entries.
     * @param conn database connection
     * @throws BrokerException
     */
    public void deleteAll( Connection conn )
        throws BrokerException {

        String whereClause = null;
        if ( Globals.getHAEnabled() ) {
            DBManager dbMgr = DBManager.getDBManager();

            // Only delete transactions that belong to the running broker,
            // construct the where clause for the delete statement:
            //   DELETE FROM mqtxn41cmycluster
            //   WHERE EXISTS
            //     (SELECT id FROM mqses41cmycluster
            //      WHERE  id = mqtxn41cmycluster.store_session_id AND
            //             broker_id = 'mybroker')
            whereClause = new StringBuffer(128)
                .append( "EXISTS (SELECT " )
                .append(   StoreSessionDAO.ID_COLUMN )
                .append(   " FROM " )
                .append(   dbMgr.getTableName( StoreSessionDAO.TABLE_NAME_PREFIX ) )
                .append(   " WHERE " )
                .append(   StoreSessionDAO.ID_COLUMN ).append( " = " )
                .append(   tableName ).append( "." ).append( STORE_SESSION_ID_COLUMN )
                .append(   " AND " )
                .append(   StoreSessionDAO.BROKER_ID_COLUMN ).append( " = '" )
                .append(   dbMgr.getBrokerID() ).append( "')" )
                .toString();
        }

        deleteAll( conn, whereClause, null, 0 );
    }

    /**
     * Get the TransactionState object.
     * @param conn database connection
     * @param txnUID the transaction ID
     * @return TransactionState object
     * @throws BrokerException
     */
    public TransactionState getTransactionState( Connection conn,
        TransactionUID txnUID ) throws BrokerException {

        TransactionState txnState = null;
        long id = txnUID.longValue();

        boolean myConn = false;
        PreparedStatement pstmt = null;
        ResultSet rs = null;
        Exception myex = null;
        try {
            // Get a connection
            if ( conn == null ) {
                conn = DBManager.getDBManager().getConnection( true );
                myConn = true;
            }

            pstmt = conn.prepareStatement( selectTxnStateSQL );
            pstmt.setLong( 1, id );
            rs = pstmt.executeQuery();
            if ( rs.next() ) {
                try {
                    int state = rs.getInt( 1 );
                    txnState = (TransactionState)Util.readObject( rs, 2 );

                    // update state in TransactionState object
                    txnState.setState( state );
                } catch ( IOException e ) {
                    // fail to parse TransactionState object; just log it
                    logger.logStack( Logger.ERROR,
                        BrokerResources.X_PARSE_TRANSACTION_FAILED, e );
                }
            } else {
                throw new BrokerException(
                    br.getKString( BrokerResources.E_TRANSACTIONID_NOT_FOUND_IN_STORE,
                    String.valueOf( id ) ), Status.NOT_FOUND );
            }
        } catch ( Exception e ) {
            myex = e;
            try {
                if ( (conn != null) && !conn.getAutoCommit() ) {
                    conn.rollback();
                }
            } catch ( SQLException rbe ) {
                logger.log( Logger.ERROR, BrokerResources.X_DB_ROLLBACK_FAILED+"["+selectTxnStateSQL+"]", rbe );
            }

            Exception ex;
            if ( e instanceof BrokerException ) {
                throw (BrokerException)e;
            } else if ( e instanceof SQLException ) {
                ex = DBManager.wrapSQLException("[" + selectTxnStateSQL + "]", (SQLException)e);
            } else {
                ex = e;
            }

            throw new BrokerException(
                br.getKString( BrokerResources.X_LOAD_TRANSACTION_FAILED,
                    txnUID ), ex );
        } finally {
            if ( myConn ) {
                Util.close( rs, pstmt, conn, myex );
            } else {
                Util.close( rs, pstmt, null, myex );
            }
        }

        return txnState;
    }

    /**
     * Get the transaction home broker for the specified transaction.
     * @param conn database connection
     * @param txnUID the transaction ID
     * @return BrokerAddress object
     * @throws BrokerException
     */
    public BrokerAddress getTransactionHomeBroker( Connection conn,
        TransactionUID txnUID ) throws BrokerException {

        BrokerAddress txnHomeBroker = null;
        long id = txnUID.longValue();

        boolean myConn = false;
        PreparedStatement pstmt = null;
        ResultSet rs = null;
        Exception myex = null;
        try {
            // Get a connection
            if ( conn == null ) {
                conn = DBManager.getDBManager().getConnection( true );
                myConn = true;
            }

            pstmt = conn.prepareStatement( selectTxnHomeBrokerSQL );
            pstmt.setLong( 1, id );
            rs = pstmt.executeQuery();
            if ( rs.next() ) {
                txnHomeBroker = (BrokerAddress)Util.readObject( rs, 1 );
            } else {
                throw new BrokerException(
                    br.getKString( BrokerResources.E_TRANSACTIONID_NOT_FOUND_IN_STORE,
                    String.valueOf( id ) ), Status.NOT_FOUND );
            }
        } catch ( Exception e ) {
            myex = e;
            try {
                if ( (conn != null) && !conn.getAutoCommit() ) {
                    conn.rollback();
                }
            } catch ( SQLException rbe ) {
                logger.log( Logger.ERROR, BrokerResources.X_DB_ROLLBACK_FAILED, rbe );
            }

            Exception ex;
            if ( e instanceof BrokerException ) {
                throw (BrokerException)e;
            } else if ( e instanceof SQLException ) {
                ex = DBManager.wrapSQLException("[" + selectTxnHomeBrokerSQL + "]", (SQLException)e);
            } else {
                ex = e;
            }

            throw new BrokerException(
                br.getKString( BrokerResources.X_LOAD_TRANSACTION_FAILED,
                    txnUID ), ex );
        } finally {
            if ( myConn ) {
                Util.close( rs, pstmt, conn, myex );
            } else {
                Util.close( rs, pstmt, null, myex );
            }
        }

        return txnHomeBroker;
    }

    /**
     * Get transaction's participant brokers for the specified transaction..
     * @param conn database connection
     * @param txnUID the transaction ID
     * @return an array of TransactionBroker object
     * @throws BrokerException
     */
    public TransactionBroker[] getTransactionBrokers( Connection conn, TransactionUID txnUID )
        throws BrokerException {

        TransactionBroker[] txnBrokers = null;
        long id = txnUID.longValue();

        boolean myConn = false;
        PreparedStatement pstmt = null;
        ResultSet rs = null;
        Exception myex = null;
        try {
            // Get a connection
            if ( conn == null ) {
                conn = DBManager.getDBManager().getConnection( true );
                myConn = true;
            }

            pstmt = conn.prepareStatement( selectTxnBrokersSQL );
            pstmt.setLong( 1, id );
            rs = pstmt.executeQuery();
            if ( rs.next() ) {
                txnBrokers = (TransactionBroker[])Util.readObject( rs, 1 );
            } else {
                throw new BrokerException(
                    br.getKString( BrokerResources.E_TRANSACTIONID_NOT_FOUND_IN_STORE,
                    String.valueOf( id ) ), Status.NOT_FOUND );
            }
        } catch ( Exception e ) {
            myex = e;
            try {
                if ( (conn != null) && !conn.getAutoCommit() ) {
                    conn.rollback();
                }
            } catch ( SQLException rbe ) {
                logger.log( Logger.ERROR, BrokerResources.X_DB_ROLLBACK_FAILED, rbe );
            }

            Exception ex;
            if ( e instanceof BrokerException ) {
                throw (BrokerException)e;
            } else if ( e instanceof SQLException ) {
                ex = DBManager.wrapSQLException("[" + selectTxnBrokersSQL + "]", (SQLException)e);
            } else {
                ex = e;
            }

            throw new BrokerException(
                br.getKString( BrokerResources.X_LOAD_TRANSACTION_FAILED,
                    txnUID ), ex );
        } finally {
            if ( myConn ) {
                Util.close( rs, pstmt, conn, myex );
            } else {
                Util.close( rs, pstmt, null, myex );
            }
        }

        return txnBrokers;
    }

    /**
     * Get the TransactionInfo object.
     * @param conn database connection
     * @param txnUID the transaction ID
     * @return TransactionInfo object
     * @throws BrokerException
     */
    public TransactionInfo getTransactionInfo( Connection conn,
        TransactionUID txnUID ) throws BrokerException {

        TransactionInfo txnInfo = null;
        long id = txnUID.longValue();

        boolean myConn = false;
        PreparedStatement pstmt = null;
        ResultSet rs = null;
        Exception myex = null;
        try {
            // Get a connection
            if ( conn == null ) {
                conn = DBManager.getDBManager().getConnection( true );
                myConn = true;
            }

            pstmt = conn.prepareStatement( selectTxnInfoSQL );
            pstmt.setLong( 1, id );

            rs = pstmt.executeQuery();
            if ( rs.next() ) {
                int type = rs.getInt( 1 );
                int state = rs.getInt( 2 );

                TransactionState txnState =
                    (TransactionState)Util.readObject( rs, 3 );

                // update state in TransactionState object
                txnState.setState( state );

                BrokerAddress txnHomeBroker =
                    (BrokerAddress)Util.readObject( rs, 4 );
                TransactionBroker[] txnBrokers =
                    (TransactionBroker[])Util.readObject( rs, 5 );

                txnInfo = new TransactionInfo( txnState, txnHomeBroker,
                    txnBrokers, type );
            } else {
                throw new BrokerException(
                    br.getKString( BrokerResources.E_TRANSACTIONID_NOT_FOUND_IN_STORE,
                    String.valueOf( id ) ), Status.NOT_FOUND );
            }
        } catch ( Exception e ) {
            myex = e;
            try {
                if ( (conn != null) && !conn.getAutoCommit() ) {
                    conn.rollback();
                }
            } catch ( SQLException rbe ) {
                logger.log( Logger.ERROR, BrokerResources.X_DB_ROLLBACK_FAILED, rbe );
            }

            Exception ex;
            if ( e instanceof BrokerException ) {
                throw (BrokerException)e;
            } else if ( e instanceof SQLException ) {
                ex = DBManager.wrapSQLException("[" + selectTxnInfoSQL + "]", (SQLException)e);
            } else {
                ex = e;
            }

            throw new BrokerException(
                br.getKString( BrokerResources.X_LOAD_TRANSACTION_FAILED,
                    txnUID ), ex );
        } finally {
            if ( myConn ) {
                Util.close( rs, pstmt, conn, myex );
            } else {
                Util.close( rs, pstmt, null, myex );
            }
        }

        return txnInfo;
    }

    /**
     * Get the time when the transaction was last accessed.
     * @param conn database connection
     * @param txnUID the transaction ID
     * @return Timestamp when the transaction was last accessed
     * @throws BrokerException
     */
    public long getAccessedTime( Connection conn, TransactionUID txnUID )
        throws BrokerException {

        long accessedTime = -1;
        long id = txnUID.longValue();

        boolean myConn = false;
        PreparedStatement pstmt = null;
        ResultSet rs = null;
        Exception myex = null;
        try {
            // Get a connection
            if ( conn == null ) {
                conn = DBManager.getDBManager().getConnection( true );
                myConn = true;
            }

            pstmt = conn.prepareStatement( selectAccessedTimeSQL );
            pstmt.setLong( 1, id );

            rs = pstmt.executeQuery();
            if ( rs.next() ) {
                accessedTime = rs.getLong( 1 );
            } else {
                throw new BrokerException(
                    br.getKString( BrokerResources.E_TRANSACTIONID_NOT_FOUND_IN_STORE,
                    String.valueOf( id ) ), Status.NOT_FOUND );
            }
        } catch ( Exception e ) {
            myex = e;
            try {
                if ( (conn != null) && !conn.getAutoCommit() ) {
                    conn.rollback();
                }
            } catch ( SQLException rbe ) {
                logger.log( Logger.ERROR, BrokerResources.X_DB_ROLLBACK_FAILED, rbe );
            }

            Exception ex;
            if ( e instanceof BrokerException ) {
                throw (BrokerException)e;
            } else if ( e instanceof SQLException ) {
                ex = DBManager.wrapSQLException("[" + selectAccessedTimeSQL + "]", (SQLException)e);
            } else {
                ex = e;
            }

            throw new BrokerException(
                br.getKString( BrokerResources.X_LOAD_TRANSACTION_FAILED,
                    txnUID ), ex );
        } finally {
            if ( myConn ) {
                Util.close( rs, pstmt, conn, myex );
            } else {
                Util.close( rs, pstmt, null, myex );
            }
        }

        return accessedTime;
    }

    /**
     * Retrieve all local and cluster transaction IDs owned by a broker.
     * @param conn database connection
     * @param brokerID the broker ID
     * @return a List of TransactionUID objects; an empty List is returned
     * if the broker does not have any transactions
     */
    public List getTransactionsByBroker( Connection conn, String brokerID )
        throws BrokerException {

        List list = new ArrayList();

        boolean myConn = false;
        PreparedStatement pstmt = null;
        ResultSet rs = null;
        Exception myex = null;
        try {
            // Get a connection
            if ( conn == null ) {
                conn = DBManager.getDBManager().getConnection( true );
                myConn = true;
            }

            // Uses the same SQL to retrieve txn states
            // but just fetchs the IDs only
            pstmt = conn.prepareStatement( selectTxnStatesByBrokerSQL );
            pstmt.setString( 1, brokerID );

            rs = pstmt.executeQuery();
            while ( rs.next() ) {
                list.add( new TransactionUID( rs.getLong( 1 ) ) );
            }
        } catch ( Exception e ) {
            myex = e;
            try {
                if ( (conn != null) && !conn.getAutoCommit() ) {
                    conn.rollback();
                }
            } catch ( SQLException rbe ) {
                logger.log( Logger.ERROR, BrokerResources.X_DB_ROLLBACK_FAILED, rbe );
            }

            Exception ex;
            if ( e instanceof BrokerException ) {
                throw (BrokerException)e;
            } else if ( e instanceof SQLException ) {
                ex = DBManager.wrapSQLException("[" + selectTxnStatesByBrokerSQL + "]", (SQLException)e);
            } else {
                ex = e;
            }

            throw new BrokerException(
                br.getKString( BrokerResources.X_LOAD_TXNS_FOR_BROKER_FAILED,
                    brokerID ), ex );
        } finally {
            if ( myConn ) {
                Util.close( rs, pstmt, conn, myex );
            } else {
                Util.close( rs, pstmt, null, myex );
            }
        }

        return list;
    }

    /**
     * Retrieve all remote transaction IDs that this broker participates in.
     * @param conn database connection
     * @param brokerID the broker ID
     * @return a List of TransactionUID objects; an empty List is returned
     * if the broker does not have any transactions
     */
    public List getRemoteTransactionsByBroker( Connection conn, String brokerID )
        throws BrokerException {

        List list = new ArrayList();

        boolean myConn = false;
        String sql = null;
        PreparedStatement pstmt = null;
        ResultSet rs = null;
        Exception myex = null;
        try {
            // Get a connection
            if ( conn == null ) {
                conn = DBManager.getDBManager().getConnection( true );
                myConn = true;
            }

            // If broker is running in non-HA mode, then just select the row
            // based on the type. Otherwise, a round about way is required
            // to retrieve the txns that the broker participates in.

            // Uses the same SQL to retrieve remote txn states
            // but just fetchs the IDs only

            if ( Globals.getHAEnabled() ) {
                sql = selectRemoteTxnStatesByBrokerAndTypeSQL;
                pstmt = conn.prepareStatement( sql );
                pstmt.setInt( 1, TransactionInfo.TXN_CLUSTER );
                pstmt.setString( 2, brokerID );
                pstmt.setString( 3, brokerID );
            } else {
                sql = selectTxnStatesByBrokerAndTypeSQL;
                pstmt = conn.prepareStatement( sql );
                pstmt.setString( 1, brokerID );
                pstmt.setInt( 2, TransactionInfo.TXN_REMOTE );
            }

            rs = pstmt.executeQuery();
            while ( rs.next() ) {
                list.add( new TransactionUID( rs.getLong( 1 ) ) );
            }
        } catch ( Exception e ) {
            myex = e;
            try {
                if ( (conn != null) && !conn.getAutoCommit() ) {
                    conn.rollback();
                }
            } catch ( SQLException rbe ) {
                logger.log( Logger.ERROR, BrokerResources.X_DB_ROLLBACK_FAILED, rbe );
            }

            Exception ex;
            if ( e instanceof BrokerException ) {
                throw (BrokerException)e;
            } else if ( e instanceof SQLException ) {
                ex = DBManager.wrapSQLException("[" +
                    selectRemoteTxnStatesByBrokerAndTypeSQL + "]", (SQLException)e);
            } else {
                ex = e;
            }

            throw new BrokerException(
                br.getKString( BrokerResources.X_LOAD_TXNS_FOR_BROKER_FAILED,
                    brokerID ), ex );
        } finally {
            if ( myConn ) {
                Util.close( rs, pstmt, conn, myex );
            } else {
                Util.close( rs, pstmt, null, myex );
            }
        }

        return list;
    }

    /**
     * Retrieve all local and cluster transaction states.
     * @param conn database connection
     * @param brokerID the broker ID
     * @return a Map of transaction IDs and TransactionState objects;
     *  an empty Map is returned if no transactions exist in the store
     */
    public HashMap getTransactionStatesByBroker( Connection conn, String brokerID )
        throws BrokerException {

        HashMap map = new HashMap();

        boolean myConn = false;
        PreparedStatement pstmt = null;
        ResultSet rs = null;
        Exception myex = null;
        try {
            // Get a connection
            DBManager dbMgr = DBManager.getDBManager();
            if ( conn == null ) {
                conn = dbMgr.getConnection( true );
                myConn = true;
            }

            if ( brokerID == null ) {
                brokerID = dbMgr.getBrokerID();
            }

            pstmt = conn.prepareStatement( selectTxnStatesByBrokerSQL );
            pstmt.setString( 1, brokerID );
            rs = pstmt.executeQuery();

            while ( rs.next() ) {
                try {
                    long id = rs.getLong( 1 );
                    int type = rs.getInt( 2 );
                    int state = rs.getInt( 3 );

                    TransactionState txnState =
                        (TransactionState)Util.readObject( rs, 4 );
                    txnState.setState( state );

                    TransactionBroker[] txnBrokers =
                        (TransactionBroker[])Util.readObject( rs, 5 );
                    
                    map.put( new TransactionUID( id ), 
                             new TransactionInfo(txnState, null, txnBrokers, type) );
                } catch ( IOException e ) {
                    // fail to parse TransactionState object; just log it
                    logger.logStack( Logger.ERROR,
                        BrokerResources.X_PARSE_TRANSACTION_FAILED, e );
                }
            }
        } catch ( Exception e ) {
            myex = e;
            try {
                if ( (conn != null) && !conn.getAutoCommit() ) {
                    conn.rollback();
                }
            } catch ( SQLException rbe ) {
                logger.log( Logger.ERROR, BrokerResources.X_DB_ROLLBACK_FAILED, rbe );
            }

            Exception ex;
            if ( e instanceof BrokerException ) {
                throw (BrokerException)e;
            } else if ( e instanceof SQLException ) {
                ex = DBManager.wrapSQLException("[" + selectTxnStatesByBrokerSQL + "]", (SQLException)e);
            } else {
                ex = e;
            }

            throw new BrokerException(
                br.getKString( BrokerResources.X_LOAD_TRANSACTIONS_FAILED ), ex );
        } finally {
            if ( myConn ) {
                Util.close( rs, pstmt, conn, myex );
            } else {
                Util.close( rs, pstmt, null, myex );
            }
        }

        return map;
    }

    /**
     * Retrieve all remote transaction states that this broker participates in.
     * @param conn database connection
     * @param brokerID the broker ID
     * @return a Map of transaction IDs and TransactionState objects;
     *  an empty Map is returned if no transactions exist in the store
     */
    public HashMap getRemoteTransactionStatesByBroker( Connection conn, String brokerID )
        throws BrokerException {

        HashMap map = new HashMap();

        boolean myConn = false;
        String sql = null;
        PreparedStatement pstmt = null;
        ResultSet rs = null;
        Exception myex = null;
        try {
            // Get a connection
            DBManager dbMgr = DBManager.getDBManager();
            if ( conn == null ) {
                conn = dbMgr.getConnection( true );
                myConn = true;
            }

            if ( brokerID == null ) {
                brokerID = dbMgr.getBrokerID();
            }

            // If broker is running in non-HA mode, then just select the row
            // based on the type. Otherwise, a round about way is required
            // to retrieve the txns that the broker participates in.

            if ( Globals.getHAEnabled() ) {
                sql = selectRemoteTxnStatesByBrokerAndTypeSQL;
                pstmt = conn.prepareStatement( sql );
                pstmt.setInt( 1, TransactionInfo.TXN_CLUSTER );
                pstmt.setString( 2, brokerID );
                pstmt.setString( 3, brokerID );
            } else {
                sql = selectTxnStatesByBrokerAndTypeSQL;
                pstmt = conn.prepareStatement( sql );
                pstmt.setString( 1, brokerID );
                pstmt.setInt( 2, TransactionInfo.TXN_REMOTE );
            }

            rs = pstmt.executeQuery();

            while ( rs.next() ) {
                try {
                    long id = rs.getLong( 1 );
                    int state = rs.getInt( 2 );
                    TransactionState txnState =
                        (TransactionState)Util.readObject( rs, 3 );

                    // update state in TransactionState object
                    txnState.setState( state );

                    map.put( new TransactionUID( id ), txnState );
                } catch ( IOException e ) {
                    // fail to parse TransactionState object; just log it
                    logger.logStack( Logger.ERROR,
                        BrokerResources.X_PARSE_TRANSACTION_FAILED, e );
                }
            }
        } catch ( Exception e ) {
            myex = e;
            try {
                if ( (conn != null) && !conn.getAutoCommit() ) {
                    conn.rollback();
                }
            } catch ( SQLException rbe ) {
                logger.log( Logger.ERROR, BrokerResources.X_DB_ROLLBACK_FAILED, rbe );
            }

            Exception ex;
            if ( e instanceof BrokerException ) {
                throw (BrokerException)e;
            } else if ( e instanceof SQLException ) {
                ex = DBManager.wrapSQLException("[" + sql + "]", (SQLException)e);
            } else {
                ex = e;
            }

            throw new BrokerException(
                br.getKString( BrokerResources.X_LOAD_TRANSACTIONS_FAILED ), ex );
        } finally {
            if ( myConn ) {
                Util.close( rs, pstmt, conn, myex );
            } else {
                Util.close( rs, pstmt, null, myex );
            }
        }

        return map;
    }

    /**
     * Return the number of messages and the number of consumer states that
     * that associate with the specified transaction ID.
     * @param conn database connection
     * @param txnUID the transaction ID
     * @return an array of int whose first element contains the number of messages
     * and the second element contains the number of consumer states.
     */
    public int[] getTransactionUsageInfo( Connection conn, TransactionUID txnUID )
        throws BrokerException {

        int[] data = { 0, 0 };

        long id = txnUID.longValue();

        boolean myConn = false;
        PreparedStatement pstmt = null;
        ResultSet rs = null;
        Exception myex = null;
        try {
            // Get a connection
            if ( conn == null ) {
                conn = DBManager.getDBManager().getConnection( true );
                myConn = true;
            }

            pstmt = conn.prepareStatement( selectUsageInfoSQL );
            pstmt.setLong( 1, id );
            pstmt.setLong( 2, id );
            rs = pstmt.executeQuery();
            if ( rs.next() ) {
                data[0] = rs.getInt( 1 );   // # of messages
                data[1] = rs.getInt( 2 );   // # of consumer states
            }
        } catch ( Exception e ) {
            myex = e;
            try {
                if ( (conn != null) && !conn.getAutoCommit() ) {
                    conn.rollback();
                }
            } catch ( SQLException rbe ) {
                logger.log( Logger.ERROR, BrokerResources.X_DB_ROLLBACK_FAILED, rbe );
            }

            Exception ex;
            if ( e instanceof BrokerException ) {
                throw (BrokerException)e;
            } else if ( e instanceof SQLException ) {
                ex = DBManager.wrapSQLException("[" + selectUsageInfoSQL + "]", (SQLException)e);
            } else {
                ex = e;
            }

            throw new BrokerException(
                br.getKString( BrokerResources.X_LOAD_TRANSACTION_FAILED,
                    txnUID ), ex );
        } finally {
            if ( myConn ) {
                Util.close( rs, pstmt, conn, myex );
            } else {
                Util.close( rs, pstmt, null, myex );
            }
        }

        return data;
    }

    /**
     * Check whether the specified transaction exists.
     * @param conn database connection
     * @param id transaction ID
     * @return return true if the specified transaction exists
     */
    public boolean hasTransaction( Connection conn, long id )
        throws BrokerException {

        boolean found = false;

        boolean myConn = false;
        PreparedStatement pstmt = null;
        ResultSet rs = null;
        Exception myex = null;
        try {
            // Get a connection
            if ( conn == null ) {
                conn = DBManager.getDBManager().getConnection( true );
                myConn = true;
            }

            pstmt = conn.prepareStatement( selectAccessedTimeSQL );
            pstmt.setLong( 1, id );
            rs = pstmt.executeQuery();
            if ( rs.next() ) {
                found = true;
            }
        } catch ( Exception e ) {
            myex = e;
            try {
                if ( (conn != null) && !conn.getAutoCommit() ) {
                    conn.rollback();
                }
            } catch ( SQLException rbe ) {
                logger.log( Logger.ERROR, BrokerResources.X_DB_ROLLBACK_FAILED, rbe );
            }

            Exception ex;
            if ( e instanceof BrokerException ) {
                throw (BrokerException)e;
            } else if ( e instanceof SQLException ) {
                ex = DBManager.wrapSQLException("[" + selectAccessedTimeSQL + "]", (SQLException)e);
            } else {
                ex = e;
            }

            throw new BrokerException(
                br.getKString( BrokerResources.X_LOAD_TRANSACTION_FAILED, 
                    String.valueOf(id) ), ex );
        } finally {
            if ( myConn ) {
                Util.close( rs, pstmt, conn, myex );
            } else {
                Util.close( rs, pstmt, null, myex );
            }
        }

        return found;
    }

    /**
     * Check whether the specified transaction exists.
     * @param conn database connection
     * @param id transaction ID
     * @throws BrokerException if the transaction does not exists in the store
     */
    public void checkTransaction( Connection conn, long id ) throws BrokerException {

        if ( !hasTransaction( conn, id ) ) {
            try {
                if ( (conn != null) && !conn.getAutoCommit() ) {
                    conn.rollback();
                }
            } catch ( SQLException rbe ) {
                logger.log( Logger.ERROR, BrokerResources.X_DB_ROLLBACK_FAILED+"[hasTransaction():"+id+"]", rbe );
            }

            throw new BrokerException(
                br.getKString( BrokerResources.E_TRANSACTIONID_NOT_FOUND_IN_STORE,
                String.valueOf( id ) ), Status.NOT_FOUND );
        }
    }

    /**
     * Get debug information about the store.
     * @param conn database connection
     * @return a HashMap of name value pair of information
     */
    public HashMap getDebugInfo( Connection conn ) {

        HashMap map = new HashMap();
        int count = -1;

        try {
            // Get row count
            count = getRowCount( null, null );
        } catch ( Exception e ) {
            logger.log( Logger.ERROR, e.getMessage(), e.getCause() );
        }

        map.put( "Transactions(" + tableName + ")", String.valueOf( count ) );
        return map;
    }
}
