logging.java

jxta_src_2.41b jxta 2.41b 最新版源码 from www.jxta.org

/*
 *  The Sun Project JXTA(TM) Software License
 *  
 *  Copyright (c) 2001-2004 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 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, 
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 *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, 
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 *  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. 
 *  
 *  $Id: Logging.java,v 1.1 2006/06/09 21:52:28 bondolo Exp $
 */

package net.jxta.logging;

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

/**
 *  This class defines constants for JXTA JSE's logging facilities. In this
 *  implementation the constants are initialized based upon the value of the
 *  Java System property {@code net.jxta.logging.Logging}. This implementation
 *  defines all of the public constants as {@code final} which enables the
 *  JVM/JIT to optimize out the logging code when appropriately configured.
 *
 *  <p/>Alternate implementations of this class could;
 * 
 *  <ul>
 *  <li>Initialize the public constants with manifest constants, ie. 
 *  {@code true} or {@code false} which would allow the Java compiler to 
 *  optimize out logging code at compile time.</li>
 *  
 *  <li>Remove the {@code static} qualifier from the constants and provide
 *  additional methods to dynamically set the logging configuration at runtime.
 *  </li>
 *  </ul>
 */
public final class Logging {
    
    /**
     *   Our Logger !
     */
    private final static Logger LOG = Logger.getLogger( Logging.class.getName() );
            
    /**
     *  The name of the system property from which we will attempt to read our
     *  logging configuration.
     */
    private final static String JXTA_LOGGING_PROPERTY = "net.jxta.logging.Logging";
    
    /**
     * The default logging level.
     */    
    private final static Level DEFAULT_LOGGING_LEVEL = Level.SEVERE;
    
    /**
     *  The logging level for this run.
     */
    public final static Level LEVEL;
    
    /**
     *  Is Level.Finest enabled?
     */
    public final static boolean FINEST;
    
    /**
     *  Is Level.Finer enabled?
     */
    public final static boolean FINER;
    
    /**
     *  Is Level.Fine enabled?
     */
    public final static boolean FINE;
    
    /**
     *  Is Level.Config enabled?
     */
    public final static boolean CONFIG;
    
    /**
     *  Is Level.Info enabled?
     */
    public final static boolean INFO;
    
    /**
     *  Is Level.Warning enabled?
     */
    public final static boolean WARNING;
    
    /**
     *  Is Level.Severe enabled?
     */
    public final static boolean SEVERE;
    
    /* Initialize the constants */
    static {
        Level setLevel = DEFAULT_LOGGING_LEVEL;
        
        try {
            setLevel = Level.parse(System.getProperty(JXTA_LOGGING_PROPERTY, DEFAULT_LOGGING_LEVEL.toString()));
        } catch(SecurityException disallowed) {
            if (LOG.isLoggable(Level.WARNING)) {
                LOG.log( Level.WARNING, "Could not read configuration property.", disallowed );
            }
        }
        
        LEVEL = setLevel;
        
        FINEST = LEVEL.intValue() >= Level.FINEST.intValue();
        FINER = LEVEL.intValue() >= Level.FINER.intValue();
        FINE = LEVEL.intValue() >= Level.FINE.intValue();
        CONFIG = LEVEL.intValue() >= Level.CONFIG.intValue();
        INFO = LEVEL.intValue() >= Level.INFO.intValue();
        WARNING = LEVEL.intValue() >= Level.WARNING.intValue();
        SEVERE = LEVEL.intValue() >= Level.SEVERE.intValue();
        
        if (Logging.CONFIG && LOG.isLoggable(Level.CONFIG)) {
            LOG.config( "Logging enabled for level : " + LEVEL );
        }
    }
    
    /** 
     * This class is not meant be instantiated.
     */
    private Logging() {
    }   
}