abstractmessagehandler.java

OpenJMS是一个开源的Java Message Service API 1.0.2 规范的实现,它包含有以下特性： *. 它既支持点到点（point-to-point）（PTP）模型和发布/订

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 * 3. The name "Exolab" must not be used to endorse or promote
 *    products derived from this Software without prior written
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 *    please contact [e-mail].
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 * 4. Products derived from this Software may not be called "Exolab"
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 *
 * THIS SOFTWARE IS PROVIDED BY EXOFFICE TECHNOLOGIES AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
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 * EXOFFICE TECHNOLOGIES OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
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 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
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 *
 * Copyright 2005 (C) Exoffice Technologies Inc. All Rights Reserved.
 *
 * $Id: AbstractMessageHandler.java,v 1.2 2005/10/20 14:07:03 tanderson Exp $
 */
package org.exolab.jms.tools.migration.proxy;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.sql.Blob;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.Message;

import org.exolab.jms.client.JmsDestination;
import org.exolab.jms.persistence.PersistenceException;
import org.exolab.jms.persistence.SQLHelper;


/**
 * Abstract implementation of the  <code>MessageHandler</code> interface.
 *
 * @author <a href="mailto:[e-mail]">Tim Anderson</a>
 * @version $Revision: 1.2 $ $Date: 2005/10/20 14:07:03 $
 */
abstract class AbstractMessageHandler implements MessageHandler, DBConstants {

    /**
     * The destination store.
     */
    private final DestinationStore _destinations;

    /**
     * The database connection.
     */
    private Connection _connection;


    /**
     * Construct a new <code>AbstractMessageHandler</code>.
     *
     * @param destinations the destination store
     * @param connection   the database connection
     */
    public AbstractMessageHandler(DestinationStore destinations,
                                  Connection connection) {
        _destinations = destinations;
        _connection = connection;
    }

    /**
     * Add a message.
     *
     * @param message the message to add
     * @throws JMSException         for any JMS error
     * @throws PersistenceException for any persistence error
     */
    public void add(Message message) throws JMSException, PersistenceException {
        add(message, getType());
    }

    /**
     * Returns a message given its identifier.
     *
     * @param messageId the identifier of the message to retrieve
     * @return the message corresponding to <code>messageId</code>
     * @throws JMSException         for any JMS error
     * @throws PersistenceException for any persistence error
     */
    public Message get(String messageId) throws JMSException,
            PersistenceException {
        Message message = newMessage();
        get(messageId, message);
        return message;
    }

    /**
     * Returns the type of message that this handler supports.
     *
     * @return the type of message
     */
    protected abstract String getType();

    /**
     * Create a new message.
     *
     * @return a new message
     * @throws JMSException for any JMS error
     */
    protected abstract Message newMessage() throws JMSException;

    /**
     * Populate the message body.
     *
     * @param body    the message body
     * @param message the message to populate
     * @throws JMSException         for any JMS error
     * @throws PersistenceException for any persistence error
     */
    protected abstract void setBody(Object body, Message message)
            throws JMSException, PersistenceException;

    /**
     * Returns the body of the message.
     *
     * @param message the message
     * @return the body of the message
     * @throws JMSException for any JMS error
     */
    protected abstract Object getBody(Message message) throws JMSException;

    /**
     * Populate a message.
     *
     * @param messageId the message identifier
     * @param message   the message to populate
     * @throws JMSException         for any JMS error
     * @throws PersistenceException for any persistence error
     */
    protected void get(String messageId, Message message)
            throws JMSException, PersistenceException {
        PreparedStatement select = null;
        ResultSet set = null;
        try {
            select = _connection.prepareStatement(
                    "select * from " + MESSAGE_TABLE + " where message_id = ?");
            select.setString(1, messageId);
            set = select.executeQuery();
            if (!set.next()) {
                throw new PersistenceException(
                        "Message not found, JMSMessageID=" + messageId);
            }
            String correlationId = set.getString("correlation_id");
            int deliveryMode = set.getInt("delivery_mode");
            long destinationId = set.getLong("destination_id");
            long expiration = set.getLong("expiration");
            int priority = set.getInt("priority");
            boolean redelivered = set.getBoolean("redelivered");
            long replyToId = set.getLong("reply_to_id");
            long timestamp = set.getLong("timestamp");
            String type = set.getString("type");

            Destination destination = _destinations.get(destinationId);

            message.setJMSMessageID(messageId);
            message.setJMSCorrelationID(correlationId);
            message.setJMSDeliveryMode(deliveryMode);
            message.setJMSDestination(destination);
            message.setJMSExpiration(expiration);
            message.setJMSPriority(priority);
            message.setJMSRedelivered(redelivered);
            if (replyToId != 0) {
                Destination replyTo = _destinations.get(replyToId);
                message.setJMSReplyTo(replyTo);
            }
            message.setJMSTimestamp(timestamp);
            message.setJMSType(type);

            Blob blob = set.getBlob("body");
            Object body;
            try {
                body = deserialize(blob);
            } catch (Exception exception) {
                throw new PersistenceException(
                        "Failed to deserialize message body, JMSMessageID="
                        + messageId, exception);
            }
            setBody(body, message);
        } catch (SQLException exception) {
            throw new PersistenceException(
                    "Failed to populate message, JMSMessageID="
                    + messageId, exception);
        } finally {
            SQLHelper.close(set);
            SQLHelper.close(select);
        }

        getProperties(messageId, message);
    }

    /**
     * Populate message properties.