Slf4j LogBack

LogBack

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概述

• Logback-core:1.1.2

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配置示例

    <logger name="LogController" level="INFO">
        <appender-ref ref="LOG" />
    </logger>

    <appender name="LOG" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <file>${log_root}/alligatorAct.log</file>
        <append>false</append>
        <filter class="ch.qos.logback.classic.filter.LevelFilter">
            <level>INFO</level>
        </filter>
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <!--日志输出位置  可相对、和绝对路径 -->
            <fileNamePattern>${log_root}/alligatorAct.%d{yyyy-MM-dd}.log</fileNamePattern>
            <!-- 可选节点，控制保留的归档文件的最大数量，超出数量就删除旧文件假设设置每个月滚动，且<maxHistory>是6，
            则只保存最近6个月的文件，删除之前的旧文件。注意，删除旧文件是，那些为了归档而创建的目录也会被删除-->
            <maxHistory>${maxHistory}</maxHistory>
        </rollingPolicy>
        <encoder>
            <charset>UTF-8</charset>
            <pattern>[%d{'MM-dd HH:mm:ss,SSS',GMT+8:00}] %-5p [%.10t][%X{CU}] %logger{36}[%L] - %m%n</pattern>
        </encoder>
    </appender>

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标签含义

• RollingFileAppender¹
  • file： 当天日志文件名称，如果没有配置，默认取回滚策略配置的文件名称
  • append：如果是 true，日志被追加到文件结尾，如果是 false，清空现存文件，默认是true
• TimeBasedRollingPolicy¹
  • fileNamePattern 配置归档日志的命名格式
    • 按天 %d{yyyy-MM-dd}
    • 按月 %d{yyyy-MM}
  • maxHistory 如果回滚策略是月，此时配置的时间是月；如果回滚策略配置的是天，此处是天数
  • cleanHistoryOnStart 是否删除历史归档日志，默认为 false
• encoder和pattern节点组合用于具体输出的日志格式²

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疑问梳理

• 为何配置了 maxHistory 历史归档日志没有被删除？
  • 因为没有开启清除开关 cleanHistoryOnStart 配置 true
  • TimeBasedRollingPolicy

    public void start() {
        this.renameUtil.setContext(this.context);
        if (this.fileNamePatternStr != null) {
            this.fileNamePattern = new FileNamePattern(this.fileNamePatternStr, this.context);
            this.determineCompressionMode();
            this.compressor = new Compressor(this.compressionMode);
            this.compressor.setContext(this.context);
            this.fileNamePatternWCS = new FileNamePattern(Compressor.computeFileNameStr_WCS(this.fileNamePatternStr, this.compressionMode), this.context);
            this.addInfo("Will use the pattern " + this.fileNamePatternWCS + " for the active file");
            if (this.compressionMode == CompressionMode.ZIP) {
                String zipEntryFileNamePatternStr = this.transformFileNamePattern2ZipEntry(this.fileNamePatternStr);
                this.zipEntryFileNamePattern = new FileNamePattern(zipEntryFileNamePatternStr, this.context);
            }

            if (this.timeBasedFileNamingAndTriggeringPolicy == null) {
                this.timeBasedFileNamingAndTriggeringPolicy = new DefaultTimeBasedFileNamingAndTriggeringPolicy();
            }

            this.timeBasedFileNamingAndTriggeringPolicy.setContext(this.context);
            this.timeBasedFileNamingAndTriggeringPolicy.setTimeBasedRollingPolicy(this);
            this.timeBasedFileNamingAndTriggeringPolicy.start();
            if (this.maxHistory != 0) {
                this.archiveRemover = this.timeBasedFileNamingAndTriggeringPolicy.getArchiveRemover();
                this.archiveRemover.setMaxHistory(this.maxHistory);
                if (this.cleanHistoryOnStart) { // 为 true 时才会清理历史归档日志
                    this.addInfo("Cleaning on start up");
                    // 清理历史归档日志
                    this.archiveRemover.clean(new Date(this.timeBasedFileNamingAndTriggeringPolicy.getCurrentTime()));
                }
            }

            super.start();
        } else {
            this.addWarn("The FileNamePattern option must be set before using TimeBasedRollingPolicy. ");
            this.addWarn("See also http://logback.qos.ch/codes.html#tbr_fnp_not_set");
            throw new IllegalStateException("The FileNamePattern option must be set before using TimeBasedRollingPolicy. See also http://logback.qos.ch/codes.html#tbr_fnp_not_set");
        }
    }

• 同时配置rollingPolicy 与 triggeringPolicy 日志无法写入

<triggeringPolicy class="ch.qos.logback.core.rolling.SizeBasedTriggeringPolicy">
	<MaxFileSize>1MB</MaxFileSize>
</triggeringPolicy>
<rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
	<FileNamePattern>/log/alligator/alligatorError.%d{yyyy-MM-dd}.%i.log</FileNamePattern>
</rollingPolicy>

• 需要更改配置³

<rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">
	<FileNamePattern>${LOG_HOME}/info.%d{yyyyMMdd}.%i.log</FileNamePattern>
	<maxFileSize>100MB</maxFileSize>
	<MaxHistory>30</MaxHistory>
</rollingPolicy>

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1. Logback各Appender详解及配置 ↩︎ ↩︎

2. Logback常用配置详解 ↩︎

3. logback每天生成日志失败，TimeBasedRollingPolicy和SizeBasedTriggeringPolicy冲突 ↩︎