log4j.xml Example

Here’s an XML version of log4j properties file, just for sharing.

1. Output to Console

Redirect the logging to console.

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration debug="true"
	xmlns:log4j='http://jakarta.apache.org/log4j/'>
	<appender name="console" class="org.apache.log4j.ConsoleAppender">
	    <layout class="org.apache.log4j.PatternLayout">
		<param name="ConversionPattern" 
		  value="%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n" />
	    </layout>
	</appender>
	<root>
		<level value="DEBUG" />
		<appender-ref ref="console" />
	</root>
</log4j:configuration>

2. Output to File

Redirect the logging to a file..

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration debug="true"
	xmlns:log4j='http://jakarta.apache.org/log4j/'>
	<appender name="file" class="org.apache.log4j.RollingFileAppender">
	   <param name="append" value="false" />
	   <param name="maxFileSize" value="10KB" />
	   <param name="maxBackupIndex" value="5" />
	   <!-- For Tomcat -->
	   <param name="file" value="${catalina.home}/logs/myStruts1App.log" />
	   <layout class="org.apache.log4j.PatternLayout">
		<param name="ConversionPattern" 
			value="%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n" />
	   </layout>
	</appender>
	<root>
		<level value="ERROR" />
		<appender-ref ref="file" />
	</root>
</log4j:configuration>

An example of log4j rolling files.

3. Output to Console and File

Full example to output the logging to both console and file.

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration debug="true"
  xmlns:log4j='http://jakarta.apache.org/log4j/'>
	<appender name="console" class="org.apache.log4j.ConsoleAppender">
	    <layout class="org.apache.log4j.PatternLayout">
		<param name="ConversionPattern" 
			value="%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n" />
	    </layout>
	</appender>
	<appender name="file" class="org.apache.log4j.RollingFileAppender">
	    <param name="append" value="false" />
	    <param name="maxFileSize" value="10MB" />
	    <param name="maxBackupIndex" value="10" />
	    <param name="file" value="${catalina.home}/logs/myStruts1App.log" />
	    <layout class="org.apache.log4j.PatternLayout">
		<param name="ConversionPattern" 
			value="%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n" />
	    </layout>
	</appender>
	<root>
		<level value="DEBUG" />
		<appender-ref ref="console" />
		<appender-ref ref="file" />
	</root>
</log4j:configuration>

References

1. Log4j 1.2 Manual
2. Log4j PatternLayout JavaDoc
3. log4j.properties examples