如何在logback中启动时滚动日志文件 [英] How to roll the log file on startup in logback

问题描述

我想配置logback以执行以下操作。

I would like to configure logback to do the following.

• 登录文件


• 当文件达到50MB时滚动文件


• 仅保留7天的日志


• 启动时始终生成新文件（滚动）

• Log to a file
• Roll the file when it reaches 50MB
• Only keep 7 days worth of logs
• On startup always generate a new file (do a roll)

除了最后一项启动滚动之外，我已经完成了所有工作。有谁知道如何实现这一目标？这是配置...

I have it all working except for the last item, startup roll. Does anyone know how to achieve that? Here's the config...

  <appender name="File" class="ch.qos.logback.core.rolling.RollingFileAppender">

    <layout class="ch.qos.logback.classic.PatternLayout">
      <Pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg \(%file:%line\)%n</Pattern>
    </layout>

    <File>server.log</File>

    <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
      <FileNamePattern>server.%d{yyyy-MM-dd}.log</FileNamePattern>
      <!-- keep 7 days' worth of history -->
      <MaxHistory>7</MaxHistory>

      <TimeBasedFileNamingAndTriggeringPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
        <MaxFileSize>50MB</MaxFileSize>
      </TimeBasedFileNamingAndTriggeringPolicy>

    </rollingPolicy>
  </appender>

推荐答案

其他建议都不适合我的情况。我不想使用基于大小和时间的解决方案，因为它需要配置MaxFileSize，我们使用严格的基于时间的策略。以下是我在启动时使用TimeBasedRollingPolicy完成滚动文件的方法：

None of the other suggestions was appropriate for my situation. I didn't want to use a size-and-time-based solution, because it requires configuring a MaxFileSize, and we are using a strictly time-based policy. Here is how I accomplished rolling the file on startup with a TimeBasedRollingPolicy:

@NoAutoStart
public class StartupTimeBasedTriggeringPolicy<E> 
        extends DefaultTimeBasedFileNamingAndTriggeringPolicy<E> {

    @Override
    public void start() {
        super.start();
        nextCheck = 0L;
        isTriggeringEvent(null, null);
        try {
            tbrp.rollover();
        } catch (RolloverFailure e) {
            //Do nothing
        }
    }

}

诀窍是将nextCheck时间设置为0L，这样isTriggeringEvent（）就会认为是时候滚动日志文件了。因此，它将执行计算文件名所需的代码，以及方便地重置nextCheck时间值。随后调用rollover（）会导致日志文件被滚动。由于这仅在启动时发生，因此它比在isTriggerEvent（）内执行比较的解决方案更优化。无论比较小，它在每条日志消息上执行时仍会略微降低性能。这也会强制在启动时立即发生翻转，而不是等待第一个日志事件。

The trick is to set the nextCheck time to 0L, so that isTriggeringEvent() will think it's time to roll the log file over. It will thus execute the code necessary to calculate the filename, as well as conveniently resetting the nextCheck time value. The subsequent call to rollover() causes the log file to be rolled. Since this only happens at startup, it is a more optimal solution than the ones that perform a comparison inside isTriggerEvent(). However small that comparison, it still degrades performance slightly when executed on every log message. This also forces the rollover to occur immediately at startup, instead of waiting for the first log event.

@NoAutoStart注释对于防止Joran执行start（）很重要在所有其他初始化完成之前的方法。否则，你得到一个NullPointerException。

The @NoAutoStart annotation is important to prevent Joran from executing the start() method before all the other initialisation is complete. Otherwise, you get a NullPointerException.

这是配置：

  <!-- Daily rollover appender that also appends timestamp and rolls over on startup -->
  <appender name="startupDailyRolloverAppender" class="ch.qos.logback.core.rolling.RollingFileAppender">
    <file>${LOG_FILE}</file>
    <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
      <fileNamePattern>${LOG_FILE}.%d{yyyyMMdd}_%d{HHmmss,aux}</fileNamePattern>
      <TimeBasedFileNamingAndTriggeringPolicy class="my.package.StartupTimeBasedTriggeringPolicy" />
    </rollingPolicy>
    <encoder>
      <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
    </encoder>
  </appender> 

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