[slf4j-user] Per Web App logging

[Ceki Gülcü]

Amir,

Holding classloaders references as keys in a map that is references by a 
class located at the server level, will prevent your application from being 
garbage collected. There is no such problem with String references which 
the JNDI approach uses.

HTH,

At 10:59 PM 11/21/2006, Amir Mistric wrote:
>Ceki
>
>After sending you the whole class (previous email) I looked over its code
>again and I also looked over this url. http://www.qos.ch/logging/sc.jsp
>
>The only significant difference I saw was that hashtable (or a hashmap in my
>case) was using a different key approach. In Log4JloggingRepository class
>the key is the Thread.currentThread().getContextClassLoader() while in
>JNDIRS is the JNDI env key. JNDIRS also doesn't have a way to pass in config
>file but other than that why would JNDI approach be more portable than
>http://wiki.jboss.org/wiki/Wiki.jsp?page=Log4jRepositorySelector ?
>
>Regards
>Amir
>
>
>
>-----Original Message-----
>From: user-bounces at slf4j.org [mailto:user-bounces at slf4j.org] On Behalf Of
>Ceki Gülcü
>Sent: Monday, November 20, 2006 5:21 PM
>To: User list for the slf4j project
>Subject: Re: [slf4j-user] Per Web App logging
>
>
>
>In the MyWebAppContextListener  code you supplied, one can read:
>
>   Log4JContextualRepositorySelector.addToRepository(pConfigFilePath);
>
>How is the addToRepository method defined?
>
>At 11:14 PM 11/20/2006, you wrote:
> >Yes it is and all we did was to rename the MyRepositorySelector class that
> >JBoss Wiki has. The code is the same as on
> >http://wiki.jboss.org/wiki/Wiki.jsp?page=Log4jRepositorySelector
> >
> >Amir
> >
> >-----Original Message-----
> >From: user-bounces at slf4j.org [mailto:user-bounces at slf4j.org] On Behalf Of
> >Ceki Gülcü
> >Sent: Monday, November 20, 2006 4:51 PM
> >To: User list for the slf4j project
> >Subject: Re: [slf4j-user] Per Web App logging
> >
> >
> >Hi Amir,
> >
> >Is the Log4JContextualRepositorySelector class yours?
> >
> >At 09:55 PM 11/20/2006, you wrote:
> > >Hi Ceki
> > >
> > >Thanks for the quick reply.
> > >Here are my answers:
> > >
> > > >If you use the JNDI-based repository selector, you can place a single
> > > >log4j.jar in the containers shared class loader. I am a little
>surprised
> > > >that you need to copy log4j.jar in each web-app. Can you please
> >elaborate?
> > >
> > >Here is the URL we used to configure the RepositorySelector.
> > >http://wiki.jboss.org/wiki/Wiki.jsp?page=Log4jRepositorySelector
> > >We have about 10 web apps running on JBoss AS and the above solution
>works.
> > >Each web app has its own WEB-INF/lib/log4j.jar and WEB-INF/log4j.xml...
> > >Also, each application has a class that implements
>ServletContextListener.
> > >
> > >public final class MyWebAppContextListener implements
> >ServletContextListener
> > >{
> > >
> > >     private ServletContext context = null;
> > >     // we cannot use Logger.getLogger until we initialize it...
> > >     private static Logger  log;
> > >
> > >...
> > >...
> > >...
> > >
> > >In this class we call (in contextInitialized() method):
> > >
> > >         this.context.log("Initializing Log4J...");
> > >         // Before using Log4J logging system, we must initialize it by
> > >adding
> > >         // the webapp specific configuration to the repository.
> > >
> >Log4JContextualRepositorySelector.addToRepository(pConfigFilePath);
> > >         // note that we can't call Logger.getLogger() until
> > >         // Log4JContextualRepositorySelector.addToRepository() is
>called.
> > >         // For all other classes in the webapp, you can call
> > >Logger.getLogger()
> > >         // at any time.
> > >         log = Logger.getLogger(FindADocContextListener.class);
> > >
> > >That is it....
> > >However this fails if we remove log4j.jar from WEB-INF/lib...
> > >
> > >
> > >I do apologize if this question is gettting off topic
> > >
> > >Amir
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >-----Original Message-----
> > >From: user-bounces at slf4j.org [mailto:user-bounces at slf4j.org] On Behalf Of
> > >Ceki Gülcü
> > >Sent: Monday, November 20, 2006 3:43 PM
> > >To: User list for the slf4j project
> > >Subject: Re: [slf4j-user] Per Web App logging
> > >
> > >Hi Amir,
> > >
> > >At 09:32 PM 11/20/2006, Amir Mistric wrote:
> > > >Hello Everyone
> > > >
> > > >My company would like to try SLF4J as a replacement for Log4J.
> > > >Currently we use JBoss AS 4.x and the problem we had was that we could
> >not
> > > >configure logging "per web application".
> > > >We ended up using RepositorySelector trick in order to be able to have
>a
> > > >separate log4j.xml in every web application deployed.
> > > >This approach, however, requires each web app to have a copy of
>log4j.jar
> > > >in its WEB-INF/lib......
> > >
> > >If you use the JNDI-based repository selector, you can place a single
> > >log4j.jar in the containers shared class loader. I am a little surprised
> > >that you need to copy log4j.jar in each web-app. Can you please
>elaborate?
> > >
> > > >Recently we decided to create a shared library repository for all web
> >apps
> > > >we have.
> > > >While this approach has reduced the "baggage" each web app had in its
> > > >WEB-INF/lib we still have to use log4j.jar ....
> > > >
> > > >Our goal is simple. Have every web application running on the same app
> > > >server have its own logging config file but share the single JAR (or
> >jars).
> > >
> > >Not yet, but it's core feature planned in one of the next releases of
> > >logback.
> > >
> > > >Can SLF4J accomplish this (using built in logback classic) for us?
> > >
> > >No, SLF4J is just a front for logback/jul/log4j/jcl. While SLF4J cannot
> > >accomplish what you are asking, log4j can do so, and logback will in the
> > >near future.
> > >
> > > >Thanks
> > > >Amir
> > >
> > >--
> > >Ceki Gülcü
> > >Logback: The reliable, generic, fast and flexible logging framework for
> > >Java.
> > >http://logback.qos.ch
> > >
> > >_______________________________________________
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> > >user at slf4j.org
> > >http://www.slf4j.org/mailman/listinfo/user
> > >
> > >_______________________________________________
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> > >user at slf4j.org
> > >http://www.slf4j.org/mailman/listinfo/user
> >
> >--
> >Ceki Gülcü
> >Logback: The reliable, generic, fast and flexible logging framework for
> >Java.
> >http://logback.qos.ch
> >
> >_______________________________________________
> >user mailing list
> >user at slf4j.org
> >http://www.slf4j.org/mailman/listinfo/user
> >
> >_______________________________________________
> >user mailing list
> >user at slf4j.org
> >http://www.slf4j.org/mailman/listinfo/user
>
>--
>Ceki Gülcü
>Logback: The reliable, generic, fast and flexible logging framework for
>Java.
>http://logback.qos.ch
>
>_______________________________________________
>user mailing list
>user at slf4j.org
>http://www.slf4j.org/mailman/listinfo/user
>
>_______________________________________________
>user mailing list
>user at slf4j.org
>http://www.slf4j.org/mailman/listinfo/user

-- 
Ceki Gülcü
Logback: The reliable, generic, fast and flexible logging framework for Java.
http://logback.qos.ch