timerthreadnamer.java

jxta平台的开发包

/*
 * $Id: TimerThreadNamer.java,v 1.3 2006/02/13 01:13:14 bondolo Exp $
 *
 * 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 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 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 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.
 *
 * ====================================================================
 *
 * 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.impl.util;

import java.util.TimerTask;

import org.apache.log4j.Logger;
import org.apache.log4j.Level;

/**
 * A simple timer task who's sole purpose is to name the Thread on which timer
 * tasks are running. You normally use it by :
 *
 * <pre><code>
 *  Timer timer = new Timer();
 *  timer.schedule( new TimerThreadNamer( "name for timer" ), 0 );
 * </code></pre>
 *
 * @deprecated Beginning with JSE 5.0 you may now name a Timer directly.
 *
 * <p/>Note that this implementation assumes the Timer implemntation found in
 * Sun JDK 1.2-1.5 (and possibly later) in that there is a single thread
 * attached to each Timer object.
 **/
public class TimerThreadNamer extends TimerTask {
    
    private final static transient Logger LOG = Logger.getLogger(TimerThreadNamer.class.getName());
    
    private boolean firstRun = true;
    
    private String nameToUse;
    
    /**
     *  Construct a Timer Thread Namer object
     *
     *  @param useName The name which the timer thread will be given.
     **/
    public TimerThreadNamer( String useName ) {
        nameToUse = useName;
        
    }
    
    /**
     *  {@inheritDoc}
     **/
    public synchronized void run() {
        
        if( firstRun ) {
            Thread.currentThread().setName( nameToUse );
            if (LOG.isEnabledFor(Level.DEBUG)) {
                LOG.debug("Naming TimerThread to : "+ nameToUse);
            }
            nameToUse = null;
            firstRun = false;
        } 
    }
}