jmsconnection.java

实现了Jms的服务器源码,支持多种适配器,DB,FTP,支持多种数据库

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 *    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.
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 * 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: JmsConnection.java,v 1.26 2004/01/11 02:33:44 tanderson Exp $
 *
 * Date         Author  Changes
 * 3/21/2000    jima    Created
 */
package org.exolab.jms.client;


import java.util.Enumeration;
import java.util.Vector;

import javax.jms.Connection;
import javax.jms.ConnectionMetaData;
import javax.jms.ExceptionListener;
import javax.jms.IllegalStateException;
import javax.jms.JMSException;

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

import org.exolab.core.service.ServiceException;
import org.exolab.jms.events.BasicEventManager;


/**
 * Client side implementation of the <code>javax.jms.Connection</code>
 * interface.
 *
 * @version     $Revision: 1.26 $ $Date: 2004/01/11 02:33:44 $
 * @author      <a href="mailto:[e-mail]">Jim Alateras</a>
 * @author      <a href="mailto:[e-mail]">Tim Anderson</a>
 */
abstract class JmsConnection implements Connection {

    /**
     * This flag indicates whether or not the connection is closed. It
     * is set to false on creation
     */
    private boolean _closed = false;

    /**
     * This flag indicates whether the connection is in the start or
     * stopped state
     */
    private boolean _stopped = true;

    /**
     * This flag indicates whether the connection has been modified.
     * If so, subsequent attempts to invoke {@link #setClientID} will
     * cause an <code>IllegalStateException</code> being thrown
     */
    private boolean _modified = false;

    /**
     * This is the identity associated with the client. The identity is
     * generated and assigned by the connection factory
     */
    private String _clientId = null;

    /**
     * Gates the setting of the clientId more than once
     */
    private boolean _clientIdSet = false;

    /**
     * A connection can maintain one and only one exception listener, The
     * listener will be informed of unusual and exception events
     */
    private ExceptionListener _exceptionListener = null;

    /**
     * Manage the list of activated and registered sessions. Everytime a
     * session is created through this connection it is registered.
     */
    private Vector _sessions = new Vector();

    /**
     * This is a back pointer to the connection factory which created this
     * connection. It is assigned during object construction
     */
    private JmsConnectionFactory _factory = null;

    /**
     * This is a stub to a remote object on the JMSSever. This abstraction
     * allows us to use different underlying ORBS.
     */
    private JmsConnectionStubIfc _stub = null;

    /**
     * The id is generated by the server and is unique for each connection
     * created. This id is then used to generate other ids
     */
    private String _connectionId = null;

    /**
     * The number of connections created
     */
    private static volatile int _activeConnections = 0;

    /**
     * The connection data is immutable at this stage. This enables us to cache
     * a single copy in memory
     */
    private static final JmsConnectionMetaData _metaData =
        new JmsConnectionMetaData();

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


    /**
     * Construct a new <code>JmsConnection</code>
     * <p>
     * This attempts to establish a connection to the JMS server
     *
     * @param factory the connection factory responsible for creating this
     * @param id the client identity
     * @param username the client username
     * @param password the client password
     * @throws JMSException if a connection cannot be established
     */
    protected JmsConnection(JmsConnectionFactory factory, String id, 
                            String username, String password)
        throws JMSException {

        if (factory == null) {
            throw new IllegalArgumentException("Argument 'factory' is null");
        }
        if (id == null) {
            throw new IllegalArgumentException("Argument 'id' is null");
        }
        if (id.trim().length() == 0) {
            throw new IllegalArgumentException("Argument 'id' is invalid: '"
                                               + id + "'");
        }

        _factory = factory;
        _clientId = id;

        _stopped = true;

        // use the factory object to retrieve the proxy that
        // will be used to get a JmsConnectionStubIfc instance
        // and cache its identity locally
        _stub = factory.getProxy().createConnection(_clientId, username,
                                                    password);
        _connectionId = _stub.getConnectionId();

        // start the event manager
        startEventManager();
    }

    // implementation of Connection.getClientID
    public String getClientID() throws JMSException {
        ensureOpen();
        setModified();

        return _clientId;
    }


    // implementation of Connection.setClientID
    public void setClientID(String id) throws JMSException {
        ensureOpen();

        // check if the client id has already been set
        if (_clientIdSet) {
            throw new IllegalStateException(
                "The client id has already been set");
        }

        if (_modified) {
            throw new IllegalStateException(
                "The client identifier must be set before any other operation "
                + "is performed");
        }

        // gate the client id from being set more than once.
        _clientId = id;
        _clientIdSet = true;
    }


    // implementation of Connection.getMetaData
    public ConnectionMetaData getMetaData() throws JMSException {
        ensureOpen();
        setModified();
        return _metaData;
    }

    // implementation of Connection.getExceptionListener
    public ExceptionListener getExceptionListener() throws JMSException {
        ensureOpen();
        setModified();
        return _exceptionListener;
    }


    // implementation of Connection.setExceptionListener
    public void setExceptionListener(ExceptionListener listener)
        throws JMSException {
        ensureOpen();
        setModified();
        _exceptionListener = listener;
    }

    /**
     * Notify the exception listener of a JMSException. If the exception
     * listener is not set then ignore it
     *
     * @param message message to deliver
     */
    public void notifyExceptionListener(JMSException message) {
        // check the error code
        if (message.getErrorCode() != null &&
            message.getErrorCode().equals(
                JmsErrorCodes.CONNECTION_TO_SERVER_DROPPED)) {
            // the connection to the server has been dropped so we need to
            // release all local resources.
            try {
                destroy();
            } catch (JMSException exception) {
                _log.error(exception.getMessage(), exception);
            }
        }

        // finally notify registered exception listener
        if (_exceptionListener != null) {
            _exceptionListener.onException(message);
        }
    }

    // implementation of Connection.start
    public synchronized void start() throws JMSException {
        ensureOpen();
        setModified();