log4j - 为什么 logger.debug 不起作用？

Question

我的 log4j.xml 文件有以下配置：

   <appender name="fileAppender"
           class="org.apache.log4j.DailyRollingFileAppender">
      <param name="Threshold" value="INFO" />
      <!-- Change Log File Root when Environment is Set Up -->
      <param name="File" value="${root}/application.log"/>
    <param name="DatePattern" value=".yyyy-MM-dd" />
      <layout class="org.apache.log4j.PatternLayout">
         <param name="ConversionPattern" value="%d{yyyy-MMM-dd HH:mm:ss,SSS} [%t] %c %x%n  %-5p %m%n"/>
      </layout>
   </appender>

   <logger name="db.scheduler" additivity="false" >
      <level value="all"/>
      <appender-ref ref="consoleAppender"/>
      <appender-ref ref="fileAppender"/>
   </logger>

但是。当我做 logger.debug 时，它不会添加任何东西！ logger.info 和 logger.error 工作...但不是 logger.debug！

Answer 1

<param name="Threshold" value="INFO" />

您的阈值设置为INFO，这是低于DEBUG 的一级，因此任何调试消息都不会通过过滤器。相关等级见here：

Level       Description
=====       ===========
OFF         The highest possible rank and is intended to
            turn off logging.
FATAL       Severe errors that cause premature termination.
            Expect these to be immediately visible on a
            status console.
ERROR       Other runtime errors or unexpected conditions.
            Expect these to be immediately visible on a
            status console.
WARN        Use of deprecated APIs, poor use of API,
            'almost' errors, other runtime situations that
            are undesirable or unexpected, but not
            necessarily "wrong". Expect these to be
            immediately visible on a status console.
INFO        Interesting runtime events (startup or
            shutdown). Expect these to be immediately
            visible on a console, so be conservative
            and keep to a minimum.
DEBUG       Detailed information on the flow through
            the system. Expect these to be written to logs
            only.
TRACE       Most detailed information. Expect these to be
            written to logs only. Since version 1.2.12.