logback的contextListener日志系统初始化

最新推荐文章于 2023-11-26 19:41:39 发布

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本文介绍如何使用Logback实现日志系统的动态配置，包括通过自定义的LoggerStartupListener类加载外部配置并定时更新日志设置的方法。此外，还提供了具体的XML配置示例，展示如何指定日志文件的路径及滚动策略。

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有时我们需要在logback中做一些动态配置，比如日志等级、输出路径等，这些信息可以存放在数据库中，启动时加载，可以用logback自带的contextListener。

<?xml version="1.0" encoding="UTF-8" ?>
<configuration debug="true" scan="true" scanPeriod="60 seconds">

<contextListener class="com.midea.jr.credit.accounting.utils.LoggerStartupListener" />
</configuration>

以上配置代表logback每隔60秒扫描logback.xml的更改，并将改动加载到系统，实现动态配置。

并在初始化之前，启动监听：LoggerStartupListener

import ch.qos.logback.classic.Level;
import ch.qos.logback.classic.Logger;
import ch.qos.logback.classic.LoggerContext;
import ch.qos.logback.classic.spi.LoggerContextListener;
import ch.qos.logback.core.Context;
import ch.qos.logback.core.spi.ContextAwareBase;
import ch.qos.logback.core.spi.LifeCycle;

public class LoggerStartupListener extends ContextAwareBase implements LoggerContextListener, LifeCycle {

	private static final String DEFAULT_LOG_FILE = "MYAPP";

	private boolean started = false;
	
	@Override
	public void start() {
		if( started )
			return;

		String userHome = System.getProperty( "user.home" );

		String logFile = System.getProperty( "log.file" ); // log.file is our custom jvm parameter to change log file name dynamicly if needed

		logFile = ( logFile != null && logFile.length() > 0 ) ? logFile : DEFAULT_LOG_FILE;

		Context context = getContext();

		context.putProperty( "MY_HOME", userHome );
		context.putProperty( "LOG_FILE", logFile );

		started = true;
	}

	@Override
	public void stop() {}

	@Override
	public boolean isStarted() {
		return started;
	}

	@Override
	public boolean isResetResistant() {
		return true;
	}

	@Override
	public void onStart( LoggerContext context ) {}

	@Override
	public void onReset( LoggerContext context ) {}

	@Override
	public void onStop( LoggerContext context ) {}

	@Override
	public void onLevelChange( Logger logger, Level level ) {}


	

}

则变量可配置到logback.xml中：

<appender name="ROOT"
        class="ch.qos.logback.core.rolling.RollingFileAppender">
        <File>${MY_HOME}/root.log</File>
        <rollingPolicy class="ch.qos.logback.core.rolling.FixedWindowRollingPolicy">
            <FileNamePattern>${MY_HOME}/root.log.%i.bak</FileNamePattern>
            <MinIndex>1</MinIndex>
            <MaxIndex>12</MaxIndex>
        </rollingPolicy>
        <triggeringPolicy
            class="ch.qos.logback.core.rolling.SizeBasedTriggeringPolicy">
            <MaxFileSize>100MB</MaxFileSize>
        </triggeringPolicy>
        <layout class="ch.qos.logback.classic.PatternLayout">
            <Pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</Pattern>
        </layout>
    </appender>