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From: "Henning P. Schmiedehausen" <hps@intermeta.de>
Newsgroups: hometree.jakarta.commons.user
Subject: Re: [logging] How do I change logging levels at run time?
Date: Mon, 11 Aug 2003 07:20:58 +0000 (UTC)
Organization: INTERMETA - Gesellschaft fuer Mehrwertdienste mbH
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 <20030810182631.Q48452@minotaur.apache.org>
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"Craig R. McClanahan" <craigmcc@apache.org> writes:

>On Mon, 11 Aug 2003 dion@multitask.com.au wrote:

>> Is this possible with commons-logging, or must we use log4j to do this?

>You'll need to use your underlying logging system's configuration
>mechanism for stuff like this.

Hi Dion, Craig,

I was thinking about this when I read about it on the maven-dev list
and this is a suggestion how to solve it (I don't know much about the
innard of commons-logging, I'm just a happy user):

The problem is, that the log level is hard coded into the method names.
You have "log.error, log.debug, log.notice" on the Log interface. 

So let's extend it with a new level called "default" (if you know any
better name, good. I wasn't able to invent a better one. ;-) :

    /**
     * <p> Is default logging currently enabled? </p>
     *
     * <p> Call this method to prevent having to perform expensive operations
     * (for example, <code>String</code> concatination)
     * when the log level is more than the default level. </p>
     */
    public boolean isDefaultEnabled();

   /**
    * <p> Log a message with default log level. </p>
    *
    * @param message log this message
    */
   public void default (Object message);

Which would use a "default" log level set by a System.property or any
other means. This would allow an application to log its stuff at debug
level when developing and at application level when running.

In the Log4JLogger this would be quite a simple implementation:

public void default (Object message) {
  logger.log(FQCN, currentPrio, message, null);
}

with isDefaultEnabled a little more heavy because one would have to
look which is<xxx>Enabled method on the logger is to be used. This
would need a little reflection or a simple switch(currentPrio)
statement.

Getting the currentPrio setting in the C'tor of Log4JLogger from a
System.property shouldn't be a problem.

I'd like to see this, it would add flexibility to the commons-logging
system while keeping the implementation independence that I like from
it.

Comments?

	Regards
		Henning


-- 
Dipl.-Inf. (Univ.) Henning P. Schmiedehausen          INTERMETA GmbH
hps@intermeta.de        +49 9131 50 654 0   http://www.intermeta.de/

Java, perl, Solaris, Linux, xSP Consulting, Web Services 
freelance consultant -- Jakarta Turbine Development  -- hero for hire

"You are being far too rational for this discussion."  
       --- Scott Robert Ladd in <3F1874B0.6030507@coyotegulch.com>