I use log4j and would like to route the output of certain Loggers to specific files.
I already have multiple appenders in place. Now, to make debugging easier, I want to tell log4j that the output generated by a specific class (e.g. foo.bar.Baz) should be written to a specific log file.
Can this be done?
An example:
log4j.rootLogger=ERROR, logfile
log4j.appender.logfile=org.apache.log4j.DailyRollingFileAppender
log4j.appender.logfile.datePattern='-'dd'.log'
log4j.appender.logfile.File=log/radius-prod.log
log4j.appender.logfile.layout=org.apache.log4j.PatternLayout
log4j.appender.logfile.layout.ConversionPattern=%-6r %d{ISO8601} %-5p %40.40c %x - %m\n
log4j.logger.foo.bar.Baz=DEBUG, myappender
log4j.additivity.foo.bar.Baz=false
log4j.appender.myappender=org.apache.log4j.DailyRollingFileAppender
log4j.appender.myappender.datePattern='-'dd'.log'
log4j.appender.myappender.File=log/access-ext-dmz-prod.log
log4j.appender.myappender.layout=org.apache.log4j.PatternLayout
log4j.appender.myappender.layout.ConversionPattern=%-6r %d{ISO8601} %-5p %40.40c %x - %m\n
Here's an answer regarding the XML configuration, note that if you don't give the file appender a ConversionPattern it will create 0 byte file and not write anything:
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
<appender name="console" class="org.apache.log4j.ConsoleAppender">
<param name="Target" value="System.out"/>
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%-5p %c{1} - %m%n"/>
</layout>
</appender>
<appender name="bdfile" class="org.apache.log4j.RollingFileAppender">
<param name="append" value="false"/>
<param name="maxFileSize" value="1GB"/>
<param name="maxBackupIndex" value="2"/>
<param name="file" value="/tmp/bd.log"/>
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%-5p %c{1} - %m%n"/>
</layout>
</appender>
<logger name="com.example.mypackage" additivity="false">
<level value="debug"/>
<appender-ref ref="bdfile"/>
</logger>
<root>
<priority value="info"/>
<appender-ref ref="bdfile"/>
<appender-ref ref="console"/>
</root>
</log4j:configuration>
Source: Stackoverflow.com