pingpresencefilter.java

用jxse开发的一个p2p通讯软件 有聊天 文件共享 视频3大功能

/*
*  Copyright (c) 2001 Sun Microsystems, Inc.  All rights
*  reserved.
*
*  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 discalimer 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 the
*  Sun Microsystems, Inc. for Project JXTA."
*  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 THE APACHE SOFTWARE FOUNDATION 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.
*  ====================================================================
*
*  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.
*
*  $Id: PingPresenceFilter.java,v 1.3 2007/05/23 21:00:17 nano Exp $
*/

package net.jxta.myjxta.dialog.filter;

import net.jxta.logging.Logging;
import net.jxta.myjxta.dialog.DialogMessage;
import net.jxta.myjxta.dialog.DialogMessageWrapper;
import net.jxta.myjxta.util.Env;

import java.util.logging.Level;
import java.util.logging.Logger;


/**
 * @author james todd [gonzo at jxta dot org]
 * @version $Id: PingPresenceFilter.java,v 1.3 2007/05/23 21:00:17 nano Exp $
 */

public class PingPresenceFilter extends AbstractDialogFilter {

    private static final Logger LOG = Logger.getLogger(PingPresenceFilter.class.getName());

    /**
     * Filters out all messages with empty text, with the text portion = "*** ping ***" and messages whose command
     * field = "ping".
     *
     * @param msg the newly received DialogMessage object
     * @return the newly modified DialogMessage object.
     */
    public DialogMessage filter(DialogMessage msg) {
        if (!processMessage((DialogMessageWrapper) msg)) {
            return msg;
        }

        // Filter out all empty messages
        String s = ((msg != null) && (msg.getHtmlMessage().length() > 0)) ? msg.getHtmlMessage() : null;
        boolean isPing = s == null;

        isPing = isPing || (s.equals(Env.PING_MESSAGE));
        isPing = isPing || ((msg.getCommand() != null) && (msg.getCommand().equalsIgnoreCase(Env.PING_COMMAND)));

        if (isPing) {
            if (Logging.SHOW_FINE && LOG.isLoggable(Level.FINE)) {
                LOG.fine("Filtering out message " +
                        System.getProperty("line.separator") + msg);
            }
            ((DialogMessageWrapper) msg).setValid(false);
        }

        return msg;
    }
}