cvs commit: jakarta-tomcat/src/share/org/apache/tomcat/logging LogHelper.java

[al...@locus.apache.org]

alex        00/06/22 16:02:54

  Added:       src/share/org/apache/tomcat/logging LogHelper.java
  Log:
  Wrapper for Logger. It has a preferred log name to write to; if it
  can't find a log with that name, it outputs to either System.out or
  System.err depending on the message's warning level.  Also prepends a
  descriptive name to each message (usually the toString() of the
  calling object), so it's easier to identify the source.
  
  Intended for use by client classes to make it easy to do reliable,
  consistent logging behavior, even if you don't necessarily have a
  context, if you're not in Tomcat, or if you haven't registered any log
  files yet.  Not intended to supplant Logger, but to allow client
  objects a consistent bit of code that prepares log messages before
  they reach logger (and does the right thing if there is no logger).
  
  Revision  Changes    Path
  1.1                  jakarta-tomcat/src/share/org/apache/tomcat/logging/LogHelper.java
  
  Index: LogHelper.java
  ===================================================================
  /*
   * ====================================================================
   * 
   * The Apache Software License, Version 1.1
   *
   * Copyright (c) 1999 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 acknowlegement:  
   *       "This product includes software developed by the 
   *        Apache Software Foundation (http://www.apache.org/)."
   *    Alternately, this acknowlegement may appear in the software itself,
   *    if and wherever such third-party acknowlegements normally appear.
   *
   * 4. The names "The Jakarta Project", "Tomcat", 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"
   *    nor may "Apache" appear in their names without prior written
   *    permission of the Apache Group.
   *
   * 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.tomcat.logging;
  
  import java.io.PrintStream;
  
  /**
   * Wrapper for Logger. It has a preferred log name to write to; if it
   * can't find a log with that name, it outputs to either System.out or
   * System.err depending on the message's warning level.  Also prepends
   * a descriptive name to each message (usually the toString() of the
   * calling object), so it's easier to identify the source.<p>
   *
   * Intended for use by client classes to make it easy to do reliable,
   * consistent logging behavior, even if you don't necessarily have a
   * context, or if you haven't registered any log files yet, or if
   * you're in a non-Tomcat application.  Not intended to supplant
   * Logger, but to allow client objects a consistent bit of code that
   * prepares log messages before they reach logger (and does the right
   * thing if there is no logger).
   *
   * @author Alex Chaffee [alex@jguru.com]
   **/
  
  public class LogHelper {
  
      private String logname;
      private Object prepend;
      private Logger logger;
  
      /**
       * @param logname name of log to use
       * @param prepend string, or an object to call toString() on, to prepend to each message
       **/
      public LogHelper(String logname, Object prepend) 
      {
  	this.logname = logname;
  	this.prepend = prepend;
      }
  
      public Logger getLogger() {
  	return logger;
      }
  
      /**
       * Set a logger explicitly. (Note that setLogger(null) will not
       * necessarily redirect log output to System.out; if there is a
       * logger named logname it will fall back to using it. )
       **/
      public void setLogger(Logger logger) {
  	this.logger = logger;
      }
  
      /**
       * Logs the message with level INFORMATION
       **/
      public void log(String msg) 
      {
  	log(msg, null, Logger.INFORMATION);
      }
  
      /**
       * Logs the Throwable with level ERROR (assumes an exception is
       * trouble; if it's not, use log(msg, t, level))
       **/
      public void log(String msg, Throwable t) 
      {
  	log(msg, t, Logger.ERROR);
      }
  
      /**
       * Logs the message and Throwable to its logger or, if logger not
       * found, to System.err or System.out (depending on level).
       **/
      public void log(String msg, Throwable t, int level)
      {
  	if (prepend != null) {
  	    msg = prepend.toString() + ": " + msg;
  	}
  
  	if (logger == null) {
  	    if (logname != null)
  		logger = Logger.getLogger(logname);
  	}
  
  	if (logger == null) {
  	    // if it's still null, send to stderr or stdout
  	    // ??? maybe should just send everything to one or the other
  	    PrintStream out = (level <= Logger.WARNING) ? System.err : System.out;
  	    out.println(msg);
  	    if (t != null)
  		out.print(TomcatLogger.throwableToString(t));
  	}
  	else {
  	    msg += "\n";
  	    logger.log(msg, t, level);
  	}
      }
  }