serversessionimpl.java

来自「OpenJMS是一个开源的Java Message Service API 1.」· Java 代码 · 共 701 行 · 第 1/2 页

/**
 * 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 [e-mail].
 *
 * 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 2000-2004 (C) Exoffice Technologies Inc. All Rights Reserved.
 *
 * $Id: ServerSessionImpl.java,v 1.2 2005/11/18 03:29:41 tanderson Exp $
 */
package org.exolab.jms.server;

import java.util.Iterator;
import java.util.List;
import javax.jms.InvalidDestinationException;
import javax.jms.JMSException;
import javax.jms.Session;
import javax.transaction.xa.XAException;
import javax.transaction.xa.XAResource;
import javax.transaction.xa.Xid;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.exolab.jms.client.JmsDestination;
import org.exolab.jms.client.JmsMessageListener;
import org.exolab.jms.client.JmsQueue;
import org.exolab.jms.client.JmsTopic;
import org.exolab.jms.message.MessageImpl;
import org.exolab.jms.messagemgr.ConsumerEndpoint;
import org.exolab.jms.messagemgr.ConsumerManager;
import org.exolab.jms.messagemgr.Flag;
import org.exolab.jms.messagemgr.MessageManager;
import org.exolab.jms.messagemgr.ResourceManager;
import org.exolab.jms.persistence.DatabaseService;
import org.exolab.jms.scheduler.Scheduler;


/**
 * A session represents a server side endpoint to the JMSServer. A client can
 * create producers, consumers and destinations through the session in addi-
 * tion to other functions. A session has a unique identifer which is a comb-
 * ination of clientId-connectionId-sessionId.
 * <p/>
 * A session represents a single-threaded context which implies that it cannot
 * be used with more than one thread concurrently. Threads registered with this
 * session are synchronized.
 *
 * @author <a href="mailto:[e-mail]">Jim Alateras</a>
 * @author <a href="mailto:[e-mail]">Tim Anderson</a>
 * @version $Revision: 1.2 $ $Date: 2005/11/18 03:29:41 $
 * @see ServerConnectionImpl
 */
class ServerSessionImpl implements ServerSession, XAResource {

    /**
     * The connection that created this session.
     */
    private final ServerConnectionImpl _connection;

    /**
     * The message manager.
     */
    private final MessageManager _messages;

    /**
     * The consumer manager.
     */
    private final ConsumerManager _consumerMgr;

    /**
     * The resource manager.
     */
    private final ResourceManager _resources;

    /**
     * Holds the current xid that this session is associated with. A session can
     * olny be associated with one xid at any one time.
     */
    private Xid _xid = null;

    /**
     * Indicates that the session has been closed.
     */
    private Flag _closed = new Flag(false);

    /**
     * The session consumer. All consumers fdr the session are managed by
     * this.
     */
    private final SessionConsumer _consumer;

    /**
     * The logger.
     */
    private static final Log _log = LogFactory.getLog(ServerSessionImpl.class);


    /**
     * Construct a new <code>ServerSessionImpl</code>.
     *
     * @param connection  the connection that created this session
     * @param ackMode     the acknowledgement mode for the session
     * @param transacted  <code>true</code> if the session is transactional
     * @param messageMgr  the message manager
     * @param consumerMgr the consumer manager
     * @param resourceMgr the resource manager
     * @param database    the database service
     * @param scheduler   the scheduler
     */
    public ServerSessionImpl(ServerConnectionImpl connection, int ackMode,
                             boolean transacted,
                             MessageManager messageMgr,
                             ConsumerManager consumerMgr,
                             ResourceManager resourceMgr,
                             DatabaseService database,
                             Scheduler scheduler) {
        _connection = connection;
        if (transacted) {
            ackMode = Session.SESSION_TRANSACTED;
        }
        _consumer = new SessionConsumer(ackMode, database, scheduler);
        _messages = messageMgr;
        _consumerMgr = consumerMgr;
        _resources = resourceMgr;
    }

    /**
     * Returns the identifier of the connection that created this session.
     *
     * @return the connection identifier
     */
    public long getConnectionId() {
        return _connection.getConnectionId();
    }

    /**
     * Acknowledge that a message has been processed.
     *
     * @param consumerId the identity of the consumer performing the ack
     * @param messageId  the message identifier
     * @throws JMSException for any error
     */
    public void acknowledgeMessage(long consumerId, String messageId)
            throws JMSException {
        _consumer.acknowledge(consumerId, messageId);
    }

    /**
     * Send a message.
     *
     * @param message the message to send
     * @throws JMSException for any error
     */
    public void send(MessageImpl message) throws JMSException {
        if (message == null) {
            throw new JMSException("Argument 'message' is null");
        }

        try {
            // set the connection identity and then let the message manager
            // process it
            message.setConnectionId(_connection.getConnectionId());

            // if there is a global transaction currently in process then
            // we must send the message to the resource manager, otherwise
            // send it directly to the message manager
            if (_xid != null) {
                _resources.logPublishedMessage(_xid, message);
            } else {
                _messages.add(message);
            }
        } catch (JMSException exception) {
            _log.error("Failed to process message", exception);
            throw exception;
        } catch (OutOfMemoryError exception) {
            String msg =
                    "Failed to process message due to out-of-memory error";
            _log.error(msg, exception);
            throw new JMSException(msg);
        } catch (Exception exception) {
            String msg = "Failed to process message";
            _log.error(msg, exception);
            throw new JMSException(msg);
        }
    }

    /**
     * Send a set of messages.
     *
     * @param messages a list of <code>MessageImpl</code> instances
     * @throws JMSException for any JMS error
     */
    public void send(List messages) throws JMSException {
        if (messages == null) {
            throw new JMSException("Argument 'messages' is null");
        }

        Iterator iterator = messages.iterator();
        while (iterator.hasNext()) {
            MessageImpl message = (MessageImpl) iterator.next();
            send(message);
        }
    }

    /**
     * Return the next available mesage to the specified consumer.
     * <p/>
     * This method is non-blocking. If no messages are available, it will return
     * immediately.
     *
     * @param consumerId the consumer identifier
     * @return the next message or <code>null</code> if none is available
     * @throws JMSException for any JMS error
     */
    public MessageImpl receiveNoWait(long consumerId) throws JMSException {
        return _consumer.receiveNoWait(consumerId);
    }

    /**
     * Return the next available message to the specified consumer.
     * <p/>
     * This method is non-blocking. However, clients can specify a
     * <code>wait</code> interval to indicate how long they are prepared to wait
     * for a message. If no message is available, and the client indicates that
     * it will wait, it will be notified via the registered {@link
     * JmsMessageListener} if one subsequently becomes available.
     *
     * @param consumerId the consumer identifier
     * @param wait       number of milliseconds to wait. A value of <code>0
     *                   </code> indicates to wait indefinitely
     * @return the next message or <code>null</code> if none is available
     * @throws JMSException for any JMS error
     */
    public MessageImpl receive(long consumerId, long wait) throws JMSException {
        return _consumer.receive(consumerId, wait);
    }

    /**
     * Browse up to count messages.
     *
     * @param consumerId the consumer identifier
     * @param count      the maximum number of messages to receive
     * @return a list of {@link MessageImpl} instances
     * @throws JMSException for any JMS error
     */
    public List browse(long consumerId, int count) throws JMSException {
        return _consumer.browse(consumerId, count);
    }

    /**
     * Create a new message consumer.
     *
     * @param destination the destination to consume messages from
     * @param selector    the message selector. May be <code>null</code>
     * @param noLocal     if true, and the destination is a topic, inhibits the
     *                    delivery of messages published by its own connection.
     *                    The behavior for <code>noLocal</code> is not specified
     *                    if the destination is a queue.
     * @return the identifty of the message consumer
     * @throws JMSException for any JMS error
     */
    public long createConsumer(JmsDestination destination, String selector,
                               boolean noLocal) throws JMSException {
        if (_log.isDebugEnabled()) {
            _log.debug("createConsumer(destination=" + destination
                       + ", selector=" + selector + ", noLocal=" + noLocal
                       + ") [session=" + this + "]");
        }

        if (destination == null) {
            throw new InvalidDestinationException(
                    "Cannot create MessageConsumer for null destination");
        }

        ConsumerEndpoint consumer = _consumerMgr.createConsumer(
                destination, _connection.getConnectionId(), selector, noLocal);
        _consumer.addConsumer(consumer);
        return consumer.getId();
    }

    /**
     * Create a new durable consumer. Durable consumers may only consume from
     * non-temporary <code>Topic</code> destinations.
     *
     * @param topic    the non-temporary <code>Topic</code> to subscribe to
     * @param name     the name used to identify this subscription
     * @param selector only messages with properties matching the message
     *                 selector expression are delivered.  A value of null or an
     *                 empty string indicates that there is no message selector
     *                 for the message consumer.
     * @param noLocal  if set, inhibits the delivery of messages published by
     *                 its own connection
     * @return the identity of the durable consumer
     * @throws JMSException for any JMS error
     */
    public long createDurableConsumer(JmsTopic topic, String name,
                                      String selector, boolean noLocal)
            throws JMSException {
        if (_log.isDebugEnabled()) {
            _log.debug("createDurableConsumer(topic=" + topic + ", name="
                       + name
                       + ", selector=" + selector + ", noLocal=" + noLocal
                       + ") [session=" + this + "]");
        }

        // if a durable subscriber with the specified name is
        // already active then this method will throw an exception.
        ConsumerEndpoint consumer = _consumerMgr.createDurableConsumer(topic,
                                                                       name,
                                                                       _connection.getClientID(),
                                                                       _connection.getConnectionId(),
                                                                       noLocal,
                                                                       selector);
        _consumer.addConsumer(consumer);
        return consumer.getId();
    }