Tomcat 6 and log4j application logging produce no output

Question

I'm trying to get log4j application (webapp) logging working in a Tomcat 6 app. I have log4j-1.2.15.jar in my WEB-INF directory, log4j.dtd and log4j.xml in WEB-INF/classes.

My log4j.xml looks like:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd" >
<log4j:configuration>
<appender name="massAppender" class="org.apache.log4j.RollingFileAppender">
    <param name="maxFileSize" value="100KB" />
    <param name="maxBackupIndex" value="2" />
    <param name="File" value="${catalina.home}/logs/mass.log" />
    <layout class="org.apache.log4j.PatternLayout">
        <param name="ConversionPattern" value="%d{ABSOLUTE} %5p %c{1}: %m%n " />
    </layout>
</appender>

<category name="com.company.mass">
    <priority value="DEBUG"/>
    <appender-ref ref="massAppender"/>
</category>

<root>
     <appender-ref ref="massAppender" />
</root>

</log4j:configuration>

My servlet is in the package:

package com.company.mass;

where the logger is declared as:

private static Logger logger = Logger.getLogger(Handler.class);

and at the top of my doGet(...) method there is:

logger.error("foo");

When I deploy the app in Tomcat and go to the servlet, it works correctly. I even get a mass.log file, but nothing gets put in it. It doesn't show up in any other logs either, and there are no obvious errors. Any idea what's going on?

Answer 1

Not sure if you need a priority in your root logger. Try this config

<category name="com.company.mass">
    <priority value="DEBUG"/> 
    <!-- no need to specify appender again here -->
</category>

<root>
    <priority value="INFO"/> 
     <appender-ref ref="massAppender" />
</root>

Answer 2

Are you sure that log4j is actually using your log4j.xml for it's configuration, and not another file on the classpath?

Enable the system property -Dlog4j.debug to have log4j print out information about exactly which configuration file it is using.

Answer 3

Here is what executing Tomcat with -Dlog4j.debug gives:

log4j: Using URL [file:/C:/dev/mass/trunk/mass/target/mass/WEB-INF/classes/log4j.xml] for automatic log4j configuration.
log4j: Preferred configurator class: org.apache.log4j.xml.DOMConfigurator
log4j: System property is :null
log4j: Standard DocumentBuilderFactory search succeded.
log4j: DocumentBuilderFactory is: com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderFactoryImpl
log4j: debug attribute= "null".
log4j: Ignoring debug attribute.
log4j: reset attribute= "false".
log4j: Threshold ="null".
log4j: Retreiving an instance of org.apache.log4j.Logger.
log4j: Setting [com.company.mass] additivity to [true].
log4j: Level value for com.company.mass is  [ERROR].
log4j: com.company.mass level set to ERROR
log4j: Level value for root is  [INFO].
log4j: root level set to INFO
log4j: Class name: [org.apache.log4j.RollingFileAppender]
log4j: Setting property [maxFileSize] to [100KB].
log4j: Setting property [maxBackupIndex] to [2].
log4j: Setting property [file] to [C:\Program Files\Apache Software Foundation\apache-tomcat-6.0.18/logs/mass.log].
log4j: Parsing layout of class: "org.apache.log4j.PatternLayout"
log4j: Setting property [conversionPattern] to [%d{ABSOLUTE} %5p %c{1}: %m%n ].
log4j: setFile called: C:\Program Files\Apache Software Foundation\apache-tomcat-6.0.18/logs/mass.log, true
log4j: setFile ended
log4j: Adding appender named [massAppender] to category [root].

Answer 4

Try adding the line :

<param name="Threshold" value="ALL" />

to your massAppender config

and this line

<priority value ="debug"/>

inside your root definition