Logback

Logback

1、官方文档

https://logback.qos.ch/manual/index.html

2、下载地址

https://logback.qos.ch/download.html

3、快速使用

这里主要是 logback + SLF4j 配合使用。

1. pom引入jar包

	<!-- 日志：slf4j + logback -->
	<dependency>
	<groupId>org.slf4j</groupId>
	<artifactId>slf4j-api</artifactId>
	<version>1.7.31</version>
	</dependency>
	<dependency>
	<groupId>ch.qos.logback</groupId>
	<artifactId>logback-core</artifactId>
	<version>1.2.3</version>
	</dependency>
	<dependency>
	<groupId>ch.qos.logback</groupId>
	<artifactId>logback-classic</artifactId>
	<version>1.2.3</version>
	<scope>compile</scope>
	</dependency>

2. src/main/resource 创建 logback.xml 文件

	<?xml version="1.0" encoding="UTF-8"?>
	<configuration scan="true" >
	<contextName>logback</contextName>
	<property name="log.path" value="./logs" />
	<property name="CONSOLE_LOG_PATTERN"
	value="%d{yyyy-MM-dd HH:mm:ss.SSS} ${LOG_LEVEL_PATTERN:-%5p} ${PID:- } --- [%15.15t] %-40.40logger{39} : %m%n}"/>
	<!--1. 输出到控制台-->
	<appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
	<!--此日志appender是为开发使用，只配置最底级别，控制台输出的日志级别是大于或等于此级别的日志信息-->
	<filter class="ch.qos.logback.classic.filter.ThresholdFilter">
	<level>INFO</level>
	</filter>
	<encoder>
	<pattern>${CONSOLE_LOG_PATTERN}</pattern>
	<!-- 设置字符集 -->
	<charset>UTF-8</charset>
	</encoder>
	</appender>
	<!--root 标签和其他logger标签起相同的作用，只是其他logger 可以继承此标签的属性-->
	<root>
	<appender-ref ref="CONSOLE" />
	</root>
	</configuration>

5. Java 代码

	package com.black.nginx.app;
	import org.slf4j.Logger;
	import org.slf4j.LoggerFactory;
	public class NginxApp {
	private static Logger logger = LoggerFactory.getLogger(NginxApp.class);
	public static void main(String[] args) {
	logger.info("app start ...");
	logger.info("app shutdown .");
	}
	}

4. 效果

	2021-07-13 23:19:41.591 INFO --- [ main] com.black.nginx.app.NginxApp : app start ...
	2021-07-13 23:19:41.596 INFO --- [ main] com.black.nginx.app.NginxApp : app shutdown .

4、logback.xml拷贝就用

• console 打印

	<?xml version="1.0" encoding="UTF-8"?>
	<!-- 日志级别从低到高分为TRACE < DEBUG < INFO < WARN < ERROR < FATAL，如果设置为WARN，则低于WARN的信息都不会输出 -->
	<!-- scan:当此属性设置为true时，配置文档如果发生改变，将会被重新加载，默认值为true -->
	<!-- scanPeriod:设置监测配置文档是否有修改的时间间隔，如果没有给出时间单位，默认单位是毫秒。
	当scan为true时，此属性生效。默认的时间间隔为1分钟。 -->
	<!-- debug:当此属性设置为true时，将打印出logback内部日志信息，实时查看logback运行状态。默认值为false。 -->
	<configuration scan="true" >
	<contextName>logback</contextName>
	<!--0. 日志格式 -->
	<property name="CONSOLE_LOG_PATTERN"
	value="%d{yyyy-MM-dd HH:mm:ss.SSS} [%-5p] [%-10.15t] %20.30logger{30}.%M[line:%L]: %m%n}"/>
	<!--1. 输出到控制台-->
	<appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
	<encoder>
	<pattern>${CONSOLE_LOG_PATTERN}</pattern>
	<!-- 设置字符集 -->
	<charset>UTF-8</charset>
	</encoder>
	</appender>
	<root>
	<appender-ref ref="CONSOLE" />
	</root>
	</configuration>

打印结果：

	2021-07-14 23:00:38.497 [INFO ] [main ] com.black.nginx.app.NginxApp.main[line:11]: app start ...
	2021-07-14 23:00:38.497 [INFO ] [main ] com.black.nginx.app.NginxApp.main[line:14]: app shutdown .

• 日志文件 1、固定文件

	<?xml version="1.0" encoding="UTF-8"?>
	<configuration scan="true" >
	<!--0. 日志格式 -->
	<property name="CONSOLE_LOG_PATTERN"
	value="%d{yyyy-MM-dd HH:mm:ss.SSS} [%-5p] [%-10.15t] %20.30logger{30}.%M[line:%L]: %m%n}"/>
	<!-- 时间戳 -->
	<timestamp key="file_name_date" datePattern="yyyyMMdd"/>
	<!--1. 记录日志到文件-->
	<appender name="LogFile" class="ch.qos.logback.core.FileAppender">
	<!-- 日志文件名 -->
	<file>${file_name_date}/log-info-${file_name_date}.log</file>
	<encoder>
	<pattern>${CONSOLE_LOG_PATTERN}</pattern>
	<!-- 设置字符集 -->
	<charset>UTF-8</charset>
	</encoder>
	</appender>
	<root>
	<appender-ref ref="LogFile" />
	</root>
	</configuration>

2、基于时间分隔文件

	<?xml version="1.0" encoding="UTF-8"?>
	<configuration scan="true" >
	<!--0. 日志格式 -->
	<property name="CONSOLE_LOG_PATTERN"
	value="%d{yyyy-MM-dd HH:mm:ss.SSS} [%-5p] [%-10.15t] %20.30logger{30}.%M[line:%L]: %m%n}"/>
	<!-- 时间戳 -->
	<timestamp key="file_name_date" datePattern="yyyyMMdd"/>
	<!--1. 记录日志到文件-->
	<appender name="ROLL_FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
	<!-- prudent 支持多个JVM 写入统一日志文件 -->
	<prudent>true</prudent>
	<!-- 设置滚动策略 -->
	<!-- FixedWindowRollingPolicy: -->
	<!-- TimeBasedRollingPolicy: -->
	<!-- SizeAndTimeBasedRollingPolicy: -->
	<rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
	<!-- 文件名以及文件路径（如果日志文件名以.gz or .zip，则半夜会自动压缩日志） -->
	<fileNamePattern>logFile.%d{yyyy-MM-dd}.log</fileNamePattern>
	<!-- 日志保留天数（如果 fileNamePattern 是按天滚动的） ，超过30天的日志会异步删除-->
	<maxHistory>30</maxHistory>
	<!-- 日志文件总大小，超过3GB时，会删除旧的日志文件 -->
	<totalSizeCap>3GB</totalSizeCap>
	</rollingPolicy>
	</appender>
	<root>
	<appender-ref ref="ROLL_FILE" />
	</root>
	</configuration>

3、基于时间和大小分隔文件

	<?xml version="1.0" encoding="UTF-8"?>
	<configuration scan="true" >
	<!--0. 日志格式 -->
	<property name="CONSOLE_LOG_PATTERN"
	value="%d{yyyy-MM-dd HH:mm:ss.SSS} [%-5p] [%-10.15t] %20.30logger{30}.%M[line:%L]: %m%n}"/>
	<!-- 时间戳 -->
	<timestamp key="file_name_date" datePattern="yyyyMMdd"/>
	<!--1. 记录日志到文件-->
	<appender name="ROLL_FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
	<!-- prudent 支持多个JVM 写入统一日志文件 -->
	<prudent>true</prudent>
	<!-- 设置滚动策略 -->
	<rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">
	<!-- 文件名以及文件路径（如果日志文件名以.gz or .zip，则半夜会自动压缩日志） -->
	<fileNamePattern>logFile.%d{yyyy-MM-dd}.%i.log</fileNamePattern>
	<!-- 每个日志文件最多100M -->
	<maxFileSize>100MB</maxFileSize>
	<!-- 日志保留天数（如果 fileNamePattern 是按天滚动的） ，超过30天的日志会异步删除-->
	<maxHistory>30</maxHistory>
	<!-- 日志文件总大小，超过20GB时，会删除旧的日志文件 -->
	<totalSizeCap>20GB</totalSizeCap>
	</rollingPolicy>
	</appender>
	<root>
	<appender-ref ref="ROLL_FILE" />
	</root>
	</configuration>

4、基于固定大小

	<?xml version="1.0" encoding="UTF-8"?>
	<configuration scan="true" >
	<!--0. 日志格式 -->
	<property name="CONSOLE_LOG_PATTERN"
	value="%d{yyyy-MM-dd HH:mm:ss.SSS} [%-5p] [%-10.15t] %20.30logger{30}.%M[line:%L]: %m%n}"/>
	<!-- 时间戳 -->
	<timestamp key="file_name_date" datePattern="yyyyMMdd"/>
	<!--1. 记录日志到文件-->
	<appender name="ROLL_FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
	<file>log-info.log</file>
	<!-- 设置滚动策略 -->
	<rollingPolicy class="ch.qos.logback.core.rolling.FixedWindowRollingPolicy">
	<fileNamePattern>log-info.%i.log.zip</fileNamePattern>
	<minIndex>1</minIndex>
	<maxIndex>3</maxIndex>
	</rollingPolicy>
	<triggeringPolicy class="ch.qos.logback.core.rolling.SizeBasedTriggeringPolicy">
	<maxFileSize>5MB</maxFileSize>
	</triggeringPolicy>
	<encoder>
	<pattern>${CONSOLE_LOG_PATTERN}</pattern>
	</encoder>
	</appender>
	<root level="INFO">
	<appender-ref ref="ROLL_FILE" />
	</root>
	</configuration>

5、logback.xml Appender 详解

• ConsoleAppender

	<configuration>
	<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
	<!-- encoders are assigned the type
	ch.qos.logback.classic.encoder.PatternLayoutEncoder by default -->
	<encoder>
	<pattern>%-4relative [%thread] %-5level %logger{35} - %msg %n</pattern>
	</encoder>
	</appender>
	<root level="DEBUG">
	<appender-ref ref="STDOUT" />
	</root>
	</configuration>

• FileAppender

	<configuration>
	<!-- Insert the current time formatted as "yyyyMMdd'T'HHmmss" under
	the key "bySecond" into the logger context. This value will be
	available to all subsequent configuration elements. -->
	<timestamp key="bySecond" datePattern="yyyyMMdd'T'HHmmss"/>
	<appender name="FILE" class="ch.qos.logback.core.FileAppender">
	<!-- use the previously created timestamp to create a uniquely
	named log file -->
	<file>log-${bySecond}.txt</file>
	<encoder>
	<pattern>%logger{35} - %msg%n</pattern>
	</encoder>
	</appender>
	<root level="DEBUG">
	<appender-ref ref="FILE" />
	</root>
	</configuration>

• RollingFileAppender

	<configuration>
	<appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
	<file>logFile.log</file>
	<rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
	<!-- daily rollover -->
	<fileNamePattern>logFile.%d{yyyy-MM-dd}.log</fileNamePattern>
	<!-- keep 30 days' worth of history capped at 3GB total size -->
	<maxHistory>30</maxHistory>
	<totalSizeCap>3GB</totalSizeCap>
	</rollingPolicy>
	<encoder>
	<pattern>%-4relative [%thread] %-5level %logger{35} - %msg%n</pattern>
	</encoder>
	</appender>
	<root level="DEBUG">
	<appender-ref ref="FILE" />
	</root>
	</configuration>

	<configuration>
	<appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
	<!-- Support multiple-JVM writing to the same log file -->
	<prudent>true</prudent>
	<rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
	<fileNamePattern>logFile.%d{yyyy-MM-dd}.log</fileNamePattern>
	<maxHistory>30</maxHistory>
	<totalSizeCap>3GB</totalSizeCap>
	</rollingPolicy>
	<encoder>
	<pattern>%-4relative [%thread] %-5level %logger{35} - %msg%n</pattern>
	</encoder>
	</appender>
	<root level="DEBUG">
	<appender-ref ref="FILE" />
	</root>
	</configuration>

	<configuration>
	<appender name="ROLLING" class="ch.qos.logback.core.rolling.RollingFileAppender">
	<file>mylog.txt</file>
	<rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">
	<!-- rollover daily -->
	<fileNamePattern>mylog-%d{yyyy-MM-dd}.%i.txt</fileNamePattern>
	<!-- each file should be at most 100MB, keep 60 days worth of history, but at most 20GB -->
	<maxFileSize>100MB</maxFileSize>
	<maxHistory>60</maxHistory>
	<totalSizeCap>20GB</totalSizeCap>
	</rollingPolicy>
	<encoder>
	<pattern>%msg%n</pattern>
	</encoder>
	</appender>
	<root level="DEBUG">
	<appender-ref ref="ROLLING" />
	</root>
	</configuration>

	<configuration>
	<appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
	<file>test.log</file>
	<rollingPolicy class="ch.qos.logback.core.rolling.FixedWindowRollingPolicy">
	<fileNamePattern>tests.%i.log.zip</fileNamePattern>
	<minIndex>1</minIndex>
	<maxIndex>3</maxIndex>
	</rollingPolicy>
	<triggeringPolicy class="ch.qos.logback.core.rolling.SizeBasedTriggeringPolicy">
	<maxFileSize>5MB</maxFileSize>
	</triggeringPolicy>
	<encoder>
	<pattern>%-4relative [%thread] %-5level %logger{35} - %msg%n</pattern>
	</encoder>
	</appender>
	<root level="DEBUG">
	<appender-ref ref="FILE" />
	</root>
	</configuration>

	<configuration>
	<appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
	<file>test.log</file>
	<rollingPolicy class="ch.qos.logback.core.rolling.FixedWindowRollingPolicy">
	<fileNamePattern>test.%i.log.zip</fileNamePattern>
	<minIndex>1</minIndex>
	<maxIndex>3</maxIndex>
	</rollingPolicy>
	<triggeringPolicy class="ch.qos.logback.core.rolling.SizeBasedTriggeringPolicy">
	<maxFileSize>5MB</maxFileSize>
	</triggeringPolicy>
	<encoder>
	<pattern>%-4relative [%thread] %-5level %logger{35} - %msg%n</pattern>
	</encoder>
	</appender>
	<root level="DEBUG">
	<appender-ref ref="FILE" />
	</root>
	</configuration>

fileNamePattern 与 Rollover关系：

fileNamePattern	Rollover schedule
/wombat/foo.%d	每天
/wombat/%d{yyyy/MM}/foo.txt	Rollover 每月开始
/wombat/foo.%d{yyyy-ww}.log	Rollover 每周第一天
/wombat/foo%d{yyyy-MM-dd_HH}.log	Rollover 每小时滚动
/wombat/foo%d{yyyy-MM-dd_HH-mm}.log	Rollover 每分钟滚动
/wombat/foo%d{yyyy-MM-dd_HH-mm, UTC}.log	Rollover 每分钟滚动
/foo/%d{yyyy-MM,aux}/%d.log	Rollover daily. Archives located under a folder containing year and month.

Rollover 就是 maxHistory 属性的单位。

6、logback.xml PatternLayout 详解

抄自https://logback.qos.ch/manual/layouts.html

我对 logback.xml 中 pattern 里的 %d %c 什么的搞不明白什么含义，下面就介绍一下，pattern 中使用到的Conversion Word的含义：

• %c{length}

或 %lo{length} %logger{length}

Conversion	Logger name	Result
%logger	mainPackage.sub.sample.Bar	mainPackage.sub.sample.Bar
%logger{0}	mainPackage.sub.sample.Bar	Bar
%logger{5}	mainPackage.sub.sample.Bar	m.s.s.Bar
%logger{10}	mainPackage.sub.sample.Bar	m.s.s.Bar
%logger{15}	mainPackage.sub.sample.Bar	m.s.sample.Bar
%logger{16}	mainPackage.sub.sample.Bar	m.sub.sample.Bar
%logger{26}	mainPackage.sub.sample.Bar	mainPackage.sub.sample.Bar

• %C{length}

或 %class{length}

打印类名

• %cn

或 contextName

• %d{pattern}

或 %date{pattern} %d{pattern, timezone} %date{pattern, timezone}

打印日期

Conversion Pattern	Result
%d	2006-10-20 14:06:49,812
%date	2006-10-20 14:06:49,812
%date{ISO8601}	2006-10-20 14:06:49,812
%date{HH:mm:ss.SSS}	14:06:49.812
%date{dd MMM yyyy;HH:mm:ss.SSS}	20 oct. 2006;14:06:49.812

• %F / %file

java 源文件的名字

• %M / %method 打印日志所在方法名

• %L / %line logger.info等代码所在文件的行数

• %m / %msg / %message 打印 用户日志信息,即 logger.info()的参数

• %n 换行

• %p / %le / %level 日志事件等级 INFO ，DEBUG等

• %r / %relative 应用启动执行，一直到打印日志，执行的毫秒数

• %t / %thread 线程名

• %ex{depth}

exception{depth} throwable{depth}

打印异常信息控制

格式	结果
%ex	mainPackage.foo.bar.TestException: Houston we have a problem at mainPackage.foo.bar.TestThrower.fire(TestThrower.java:22) at mainPackage.foo.bar.TestThrower.readyToLaunch(TestThrower.java:17) at mainPackage.ExceptionLauncher.main(ExceptionLauncher.java:38)
%ex{short}	mainPackage.foo.bar.TestException: Houston we have a problem at mainPackage.foo.bar.TestThrower.fire(TestThrower.java:22)
%ex{full}	mainPackage.foo.bar.TestException: Houston we have a problem at mainPackage.foo.bar.TestThrower.fire(TestThrower.java:22) at mainPackage.foo.bar.TestThrower.readyToLaunch(TestThrower.java:17) at mainPackage.ExceptionLauncher.main(ExceptionLauncher.java:38)
%ex{2}	mainPackage.foo.bar.TestException: Houston we have a problem at mainPackage.foo.bar.TestThrower.fire(TestThrower.java:22) at mainPackage.foo.bar.TestThrower.readyToLaunch(TestThrower.java:17)

• %property{key} 打印Properties文件中的key 对应的 value

• %caller{depth} 打印方法调用层级信息

7、logback.xml Format modifiers 详解

Format modifier	左对齐	最小宽度	最大宽度	评论
%20logger	否	20	无	如果小于20字符则默认右对齐
%-20logger	是	20	无	如果小于20字符则左对齐
%.10logger	NA	无	30	超出30字符则删除 com.black.nginx.app.NginxApp 会打印出：p.NginxApp
%20.30logger	否	20	30	如果超过30个字符，则将从末尾开始截取30个字符打印
%-20.30logger	是	20	30	如果超过30个字符，则将从开头开始截取30个字符打印
%.-30logger	NA	无	30	如果超过30个字符，则将从开头开始截取30个字符打印