[slf4j-user] Per-web-app logging with jars on the server's classpath

[Mark Stralka]

Jacob Kjome <hoju <at> visi.com> writes:

> 
> That's an interesting finding.  When it worked for you, did you have 
> to use the WEB-INF/weblogic.xml file I suggested might be necessary 
> in a previous email, or did it work without that? BTW, where do you 
> put commons-logging.jar and slf4j jars?  Are they in the server 
> classpath as well alongside log4j.jar?  Actually, I can't see how it 
> couldn't be.  If your framework extends Spring, Spring jars and their 
> dependencies would also have to be on the server classpath.  Given 
> this, I hope all the libraries use non-static loggers.

I did not have to use weblogic.xml - I only had to put the 2 env-entries 
into
web.xml.

All of the JAR files are on the server's classpath along with log4j.jar, and
Spring classes do not use static loggers (which is good for me!).  Instead of
the official commons-logging.jar I was using jcl104-over-slf4j-1.3.0.jar, but
now because of the problem I'm having using JCL, I may have to write my own JCL
implementation to use log4j 1.3 directly instead of SLF4j.  I just downloaded
JCL 1.1 source but it appears to still use log4j 1.2.

> 
> This is getting out of my area of expertise.  I'm a Log4j developer, 
> not an SLF4J developer.  Ceki may have some ideas here.  I find it 
> odd that wrappers would have an effect whatsoever.  If all they are 
> doing is forwarding to Log4j then, ultimately, Log4j should be 
> controlling which logger repository is used.
> 
> BTW, do you have a default config file (log4j.properties or 
> log4j.xml) in the server's classpath that Log4j uses to configure its 
> default logger repository?  If so, does it point to the same Log file 
> as appA?  If it does, then that could be the culprit.  Wrapped 
> loggers might be logging to the default logger 
> repository.  Otherwise, I find it odd that the repository selector 
> would be arbitrarily (but consistently) choosing a non-default logger 
> repository to log to.

I do not have a default log4j.properties or log4j.xml file anywhere on the
classpath.

We've definitely made progress and I can now write log messages to separate
files as needed.  Now I want to get JCL working correctly.  I've made some
progress with that already - I started with SLF4JLog and SLF4JLogFactory, copied
them to MyFrameworkLog and MyFrameworkLogFactory, cut out all references to
SLF4J, and made them use Log4J directly.  JCL writes to separate log files this
way, but the log messages include the incorrect class name in the conversion 
layout.

Here's the conversion layout:
log4j.appender.file.layout.ConversionPattern=%d{dd MMM yyyy HH:mm:ss,SSS} %5p
%C{1} - %m%n

The log entries from a class called "UserFormController" should look like this
(and does if I use Log4j directly without JCL):
17 Mar 2007 13:00:39,087  INFO UserFormController - entering formBackingObject()

using the JCL with my custom Log4j Log and LogFactory, it looks like this:
17 Mar 2007 13:00:39,087  INFO MyFrameworkLog - entering formBackingObject()

So I need to figure out where %C is turned into a classname... any thoughts?

Thanks
Mark