commons-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From rdon...@apache.org
Subject cvs commit: jakarta-commons/digester/src/java/org/apache/commons/digester/plugins LogUtils.java
Date Tue, 28 Oct 2003 23:31:38 GMT
rdonkin     2003/10/28 15:31:38

  Added:       digester/src/java/org/apache/commons/digester/plugins
                        LogUtils.java
  Log:
  Improvements to bring logging in line with the practice in the rest of digester.  Submitted
by Simon Kitching.
  
  Revision  Changes    Path
  1.1                  jakarta-commons/digester/src/java/org/apache/commons/digester/plugins/LogUtils.java
  
  Index: LogUtils.java
  ===================================================================
  /*
   * $Header: /home/cvs/jakarta-commons/digester/src/java/org/apache/commons/digester/plugins/LogUtils.java,v
1.1 2003/10/28 23:31:38 rdonkin Exp $
   * $Revision: 1.1 $
   * $Date: 2003/10/28 23:31:38 $
   *
   * ====================================================================
   * 
   * The Apache Software License, Version 1.1
   *
   * Copyright (c) 2001-2003 The Apache Software Foundation.  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 acknowledgement:  
   *       "This product includes software developed by the 
   *        Apache Software Foundation (http://www.apache.org/)."
   *    Alternately, this acknowledgement may appear in the software itself,
   *    if and wherever such third-party acknowledgements normally appear.
   *
   * 4. The names "Apache", "The Jakarta Project", "Commons", and "Apache Software
   *    Foundation" must not be used to endorse or promote products derived
   *    from this software without prior written permission. For written 
   *    permission, please contact apache@apache.org.
   *
   * 5. Products derived from this software may not be called "Apache",
   *    "Apache" nor may "Apache" appear in their names without prior 
   *    written permission of the Apache Software Foundation.
   *
   * 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 the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.apache.org/>.
   *
   */ 
  package org.apache.commons.digester.plugins;
  
  import org.apache.commons.digester.Digester;
  import org.apache.commons.logging.Log;
  
  /**
   * Simple utility class to assist in logging.
   * <p>
   * The Digester module has an interesting approach to logging:
   * all logging should be done via the Log object stored on the
   * digester instance that the object *doing* the logging is associated
   * with.
   * <p>
   * This is done because apparently some "container"-type applications
   * such as Avalon and Tomcat need to be able to configure different logging
   * for different <i>instances</i> of the Digester class which have been
   * loaded from the same ClassLoader [info from Craig McClanahan]. 
   * Not only the logging of the Digester instance should be affected; all 
   * objects associated with that Digester instance should obey the 
   * reconfiguration of their owning Digester instance's logging. The current 
   * solution is to force all objects to output logging info via a single 
   * Log object stored on the Digester instance they are associated with.
   * <p>
   * Of course this causes problems if logging is attempted before an
   * object <i>has</i> a valid reference to its owning Digester. The 
   * getLogging method provided here resolves this issue by returning a
   * Log object which silently discards all logging output in this
   * situation.
   * <p>
   * And it also implies that logging filtering can no longer be applied
   * to subcomponents of the Digester, because all logging is done via
   * a single Log object (a single Category). C'est la vie...
   * 
   * @author Simon Kitching
   */
  
  public class LogUtils {
      
    /**
     * Get the Log object associated with the specified Digester instance,
     * or a "no-op" logging object if the digester reference is null.
     * <p>
     * You should use this method instead of digester.getLogger() in
     * any situation where the digester might be null.
     */
    public static Log getLogger(Digester digester) {
      if (digester == null) {
          return new org.apache.commons.logging.impl.NoOpLog();
      }
      
      return digester.getLogger();
    }
  }
  
  
  

---------------------------------------------------------------------
To unsubscribe, e-mail: commons-dev-unsubscribe@jakarta.apache.org
For additional commands, e-mail: commons-dev-help@jakarta.apache.org


Mime
View raw message