Using your own log4j.properties file - class loader scoping

To use a log4j.properties file, you have to make the change in conf/jboss-service.xml as shown below. This is necessary for the reasons mentioned above. Essentially you are changing the log4j resource file that jBossAS will look for. After making the change in jboss-service.xml make sure you rename the conf/log4j.xml to the name that you have give in jboss-service.xml (in this case jboss-log4j.xml).

<!-- ==================================================================== -->
<!-- Log4j Initialization                                                 -->
<!-- ==================================================================== -->

<mbean code="org.jboss.logging.Log4jService"
 name="jboss.system:type=Log4jService,service=Logging">
 <attribute name="ConfigurationURL">resource:jboss-log4j.xml</attribute>
 <!-- Set the org.apache.log4j.helpers.LogLog.setQuiteMode. As of log4j1.2.8
 this needs to be set to avoid a possible deadlock on exception at the
 appender level. See bug#696819.
 -->
 <attribute name="Log4jQuietMode">true</attribute>
 <!-- How frequently in seconds the ConfigurationURL is checked for changes -->
 <attribute name="RefreshPeriod">60</attribute>
</mbean>

Drop log4j.jar in your myapp.war/WEB-INF. Make the change in jboss-web.xml for class-loading, as shown in the section above. In this case, myapp.war/WEB-INF/jboss-web.xml looks like this:

<jboss-web>
 <class-loading java2ClassLoadingCompliance="false">
   <loader-repository>
      myapp:loader=myapp.war
      <loader-repository-config>java2ParentDelegation=false</loader-repository-config>
   </loader-repository>
 </class-loading>
</jboss-web>

Now, in your deploy/myapp.war/WEB-INF/classes create a log4j.properties. Sample log4j.properties:

# Debug log4j
log4j.debug=true  

log4j.rootLogger=debug, myapp

log4j.appender.myapp=org.apache.log4j.FileAppender
log4j.appender.myapp.layout=org.apache.log4j.HTMLLayout
log4j.appender.myapp.layout.LocationInfo=true
log4j.appender.myapp.layout.Title='All' Log
log4j.appender.myapp.File=${jboss.server.home.dir}/deploy/myapp.war/WEB-INF/logs/myapp.html
log4j.appender.myapp.ImmediateFlush=true
log4j.appender.myapp.Append=false

The above property file sets the log4j debug system to true, which displays log4j messages in your jboss log. You can use this to discover errors, if any in your properties file. It then produces a nice HTML log file and places it in your application's WEB-INF/logs directory. In your application, you can call this logger with the syntax:

...
private static Logger log = Logger.getLogger("myapp");
...
log.debug("############## A debug message from myapp logger #########");
...

If all goes well, you should see this message in myapp.html. For more information about loggers, appenders and layouts, visit the log4j website.

After jBossAS has reloaded conf/jboss-service.xml (you may have to restart jBossAS), touch myapp.war/WEB-INF/web.xml so that jboss reloads the config for your application. As the application loads you should see log4j debug messages showing that its reading your log4j.properties. And voila, you have your own logging system, independent of the jBoss logging system.

Referenced by: