/*
 * Copyright (c) 2001-2007 Sun Microsystems, Inc.  All rights reserved.
 *  
 *  The Sun Project JXTA(TM) Software License
 *  
 *  Redistribution and use in source and binary forms, with or without 
 *  modification, are permitted provided that the following conditions are met:
 *  
 *  1. Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
 *  
 *  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 end-user documentation included with the redistribution, if any, must 
 *     include the following acknowledgment: "This product includes software 
 *     developed by Sun Microsystems, Inc. for JXTA(TM) technology." 
 *     Alternately, this acknowledgment may appear in the software itself, if 
 *     and wherever such third-party acknowledgments normally appear.
 *  
 *  4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA" must 
 *     not be used to endorse or promote products derived from this software 
 *     without prior written permission. For written permission, please contact 
 *     Project JXTA at http://www.jxta.org.
 *  
 *  5. Products derived from this software may not be called "JXTA", nor may 
 *     "JXTA" appear in their name, without prior written permission of Sun.
 *  
 *  THIS SOFTWARE IS PROVIDED ``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 SUN 
 *  MICROSYSTEMS 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.
 *  
 *  JXTA is a registered trademark of Sun Microsystems, Inc. in the United 
 *  States and other countries.
 *  
 *  Please see the license information page at :
 *  <http://www.jxta.org/project/www/license.html> for instructions on use of 
 *  the license in source files.
 *  
 *  ====================================================================
 *  
 *  This software consists of voluntary contributions made by many individuals 
 *  on behalf of Project JXTA. For more information on Project JXTA, please see 
 *  http://www.jxta.org.
 *  
 *  This license is based on the BSD license adopted by the Apache Foundation. 
 */
package net.jxta.endpoint;

/**
 * A listener for events concerning the status of outgoing messages.
 */
public interface OutgoingMessageEventListener extends java.util.EventListener {

    /**
     * The message identified by the event could not be sent.
     * <p/>
     * The cause of the failure, if any, is available from
     * {@link OutgoingMessageEvent#getFailure()}. Failures while sending
     * messages have several causes :
     * <p/>
     * <ul>
     * <li>An {@link java.io.IOException} means that the messenger cannot
     * send the message and the messenger will accept no further messages
     * to be sent.</li>
     * <p/>
     * <li>A {@link java.lang.RuntimeException} mean that the message was
     * not sent, but retries may or may not be possible based upon the
     * status returned by {@link Messenger#isClosed()}.</li>
     * <p/>
     * <li><code>null</code> means that the message was not sent, but may
     * be retried. Usually the failure is due to local resource limits
     * being exceeded. Attempts may be made to later resend the message,
     * usually after waiting for congestion to clear.</li>
     * </ul>
     * @param event the event
     */
    void messageSendFailed(OutgoingMessageEvent event);

    /**
     * The message identified by the event was successfully sent. Successfully
     * sending a message is not a guarantee that it will be successfully
     * received by the destination.
     * @param event the event
     */
    void messageSendSucceeded(OutgoingMessageEvent event);
}