How do I configure log4j using log4j.xml to append to different log files based on class name?

Question

I want to set up log4j so that all log meessages produced from classes under package com.foo.bar go to bar.log, and all the log meessages produced from classes under package

Answer 1

This is based on my answer to a similar question:

<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
    <!-- general application log -->
    <appender name="BarLogFile" class="org.apache.log4j.FileAppender">
        <param name="File" value="bar.log" />
        <param name="Threshold" value="INFO" />
        <layout class="org.apache.log4j.PatternLayout">
            <param name="ConversionPattern" value="%-5p %t [%-40.40c] %x - %m%n"/>
        </layout>
    </appender> 

    <!-- additional fooSystem logging -->
    <appender name="BlatzLogFile" class="org.apache.log4j.FileAppender">
        <param name="File" value="blatz.log" />
        <layout class="org.apache.log4j.PatternLayout">
            <param name="ConversionPattern" value="%-5p %t [%-40.40c] %x - %m%n"/>
        </layout>
    </appender>

    <logger name="com.foo.bar">
        <appender-ref ref="BarLogFile"/>
    </logger>

    <logger name="com.bar.blatz">
        <appender-ref ref="BlatzLogFile"/>
    </logger>

    <root>
        <level value="INFO"/>
        <!-- no appender, output will be swallowed (I think) -->
    </root>
</log4j:configuration>

If you add an appender-ref to the root element, it will also receive com.foo.bar etc messages. You can stop that by specifying 'additivity="false"' on the loggers.

Answer 2

  <root>
        <level value="INFO"/>
        <!-- no appender, output will be swallowed (I think) -->
  </root>

We can add appenders here. It will work if the application is using root logger. for example quartz Scheduler API.