log4j xml配置问题

Question

我没有什么问题,我的log4j.xml配置如下所示

<?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>
     <logger name="com.alsodeep">
        <level value="info" />
        <appender-ref ref="console" />
    </logger>  
    <logger name="org.springframework">
        <level value="error" />
        <appender-ref ref="console" />
    </logger>
    <root>
        <priority value="error" />
        <appender-ref ref="console" />
    </root>

</log4j:configuration>

当我在com.alsodeep包中调用log.info("some info")时,它打印出两次,例如

INFO  AspectExample - Call it before method
INFO  AspectExample - Call it before method
Hello
INFO  AspectExample - Call it after method
INFO  AspectExample - Call it after method
List content [[23, 243, 234, 23432]]
INFO  App - final
INFO  App - final

我对此感到困惑,我的log4j设置有什么问题.

PS当我从根元素中删除appender时,一切正常,我的日志信息只出现一次.

Answer 1

去掉:

<appender-ref ref="console" />

从特定记录器中只留下一个在根记录器中:

<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>
     <logger name="com.alsodeep">
        <level value="info" />
    </logger>  
    <logger name="org.springframework">
        <level value="error" />
    </logger>
    <root>
        <priority value="error" />
        <appender-ref ref="console" />
    </root>

</log4j:configuration>

您的配置是有效的,但是当您尝试记录某些内容时com.alsodeep,它首先会获得直接与此记录器关联的appender,然后向上传播.com没有关联的appender,但是root(所有记录器的父级)都有.巧合的是,它是相同的控制台appender,因此它会被附加两次.