Qual diferença entre log4j.xml e log4j.properties[resolvido]

log4j.rootLogger=ERROR, stdout
#log4j.category.org.hibernate.cache=DEBUG
#log4j.category.org.springframework.transaction=DEBUG
#log4j.category.org.springframework.orm=DEBUG
#log4j.category.org.hibernate.SQL=DEBUG
#log4j.category.org.hibernate.type=DEBUG

log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d %p [%c] - <%m>%n

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">

	<appender name="stdout" class="org.apache.log4j.ConsoleAppender">
		<layout class="org.apache.log4j.PatternLayout">
			<param name="ConversionPattern" value="%d{HH:mm:ss,SSS} %5p [%-20c{1}] %m%n" />
		</layout>
	</appender>

	<category name="org.vraptor">
		<priority value="INFO" />
		<appender-ref ref="stdout" />
	</category>

	<category name="com.thoughtworks">
		<priority value="INFO" />
		<appender-ref ref="stdout" />
	</category>

	<category name="br.com.caelum.vraptor">
		<priority value="INFO" />
		<appender-ref ref="stdout" />
	</category>

	<category name="org.springframework">
		<priority value="INFO" />
		<appender-ref ref="stdout" />
	</category>

</log4j:configuration>