logging-log4j-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Lutz Michael <michael.h.l...@siemens.com>
Subject RE: calling DOMConfigurator.configureAndWatch() 2 times
Date Wed, 13 Aug 2003 13:47:53 GMT


Also, it is programmatically possible to check if Log4j has been configured
previously, thus avoiding the problem (which may or may not help in this
particular case).  My development team creates components used throughout
our enterprise, and if an application has configured Log4j, we want to avoid
configuring it ourselves and instead piggy-back off their configuration.  If
not, then we of course need to configure Log4j independently.  We always
check first to see if Log4j has been configured, and if and only if it has
not, do we actually configure it at run-time.

The code to check if Log4j has been configured follows:

public static boolean isConfigured() {
      java.util.Enumeration enum = Logger.getRoot().getAllAppenders();
      if ((enum != null) && (!(enum instanceof
org.apache.log4j.helpers.NullEnumeration))) {
          return true;
      }
      else {
          java.util.Enumeration loggers =
org.apache.log4j.LogManager.getCurrentLoggers() ;
          while (loggers.hasMoreElements()) {
              Logger c = (Logger) loggers.nextElement();
              if (!(c.getAllAppenders() instanceof
org.apache.log4j.helpers.NullEnumeration))
                  return true;
          }
      }
      return false;
  }



-----Original Message-----
From: Shapira, Yoav [mailto:Yoav.Shapira@mpi.com]
Sent: Wednesday, August 13, 2003 9:18 AM
To: Log4J Users List
Subject: RE: calling DOMConfigurator.configureAndWatch() 2 times 



Howdy,

>What should happen if the configureAndWatch() function is called twice?
>Are the previous settings erased? Are they accumulated ?

It wouldn't be that hard to simply test this and see what happens ;)

But looking at the code, you see:

- configureAndWatch always creates a new XMLWatchdog, so you will have
two XMLWatchdogs watching over the file.  

- Each XMLWatchdog would call DOMConfigurator#doConfigure(filename,
repository) when the file changes, so this method will get called twice.
So this is extra overhead that should be avoided if possible.

- The configuration file will get parsed again with a new parser

- Parsing will replace where found and add where not found.  So if
there's already a logger for class, for example, it will be retrieved if
it exists and reconfigured, or a new one will be created if one doesn't
exist.

You can walk through the rest of DOMConfigurator if you feel like it ;)
This is one issue where the test is easy so I wouldn't even spend time
looking at the code ;)

Yoav Shapira



This e-mail, including any attachments, is a confidential business
communication, and may contain information that is confidential, proprietary
and/or privileged.  This e-mail is intended only for the individual(s) to
whom it is addressed, and may not be saved, copied, printed, disclosed or
used by anyone else.  If you are not the(an) intended recipient, please
immediately delete this e-mail from your computer system and notify the
sender.  Thank you.


---------------------------------------------------------------------
To unsubscribe, e-mail: log4j-user-unsubscribe@jakarta.apache.org
For additional commands, e-mail: log4j-user-help@jakarta.apache.org

-------------------------------------------------------------------------------
This message and any included attachments are from Siemens Medical Solutions 
USA, Inc. and are intended only for the addressee(s).  
The information contained herein may include trade secrets or privileged or 
otherwise confidential information.  Unauthorized review, forwarding, printing, 
copying, distributing, or using such information is strictly prohibited and may 
be unlawful.  If you received this message in error, or have reason to believe 
you are not authorized to receive it, please promptly delete this message and 
notify the sender by e-mail with a copy to CSOffice@smed.com.  Thank you

---------------------------------------------------------------------
To unsubscribe, e-mail: log4j-user-unsubscribe@jakarta.apache.org
For additional commands, e-mail: log4j-user-help@jakarta.apache.org


Mime
View raw message