log4j(一)

log4j配置：

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

<!-- 控制台输出 -->

<appender name="stdout" class="org.apache.log4j.ConsoleAppender">
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%d %p [%c] - %m%n"/>
</layout>
</appender>

    <appender name="errorAppender" class="org.apache.log4j.DailyRollingFileAppender">
<param name="File" value="logs/error.log"/>
<param name="DatePattern" value="'.'yyyy-MM-dd"/>
<layout  class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="[%d][%X{clientIP}] - %m%n"/>
   </layout>
<filter class="org.apache.log4j.varia.LevelRangeFilter">
<param name="LevelMin" value="ERROR" />
<param name="LevelMax" value="ERROR" />
</filter>
</appender>

        <!-- errorLogger -->
<category name="errorLogger" additivity="false">  
<level value="ERROR"/>
<appender-ref ref="stdout"/>
<appender-ref ref="errorAppender" />  
</category>

</log4j:configuration>