Slf4j+Log4j简单使用

一、引入依赖

<dependencies><dependency><groupId>org.slf4j</groupId><artifactId>slf4j-api</artifactId><version>1.7.36</version></dependency><dependency><groupId>org.apache.logging.log4j</groupId><artifactId>log4j-slf4j-impl</artifactId><version>2.23.1</version></dependency>
</dependencies>

二、配置 log4j2.xml

2.1 配置结构

2.2 配置文件

<?xml version="1.0" encoding="UTF-8"?>
<Configuration xmlns="http://logging.apache.org/log4j/2.0/config" status="TRACE" monitorInterval="30"><Properties><Property name="PROJECT_NAME">log4j2-example</Property><Property name="LOG_PATH">./data/logs</Property><Property name="pattern">[%d{yyyy-MM-dd HH:mm:ss,SSS}] [%c{1.}::%M] [%t] [%p]: %m%n</Property></Properties><Appenders><Console name="Console" target="SYSTEM_OUT"><PatternLayout pattern="${pattern}"/></Console><RollingFile name="RollingFile" fileName="${LOG_PATH}/${PROJECT_NAME}.log"filePattern="${LOG_PATH}/${date:yyyy-MM-dd}/${PROJECT_NAME}-%d{yyyy-MM-dd}-%i.log"><PatternLayout pattern="${pattern}"/><Policies><TimeBasedTriggeringPolicy interval="1" modulate="true"/><SizeBasedTriggeringPolicy size="100 MB"/></Policies></RollingFile></Appenders><Loggers><Root level="info"><appender-ref ref="Console"/><appender-ref ref="RollingFile"/></Root></Loggers>
</Configuration>

三、使用

package com.chenjiacheng.log.log4j2.log;import org.slf4j.Logger;
import org.slf4j.LoggerFactory;/*** Created by chenjiacheng on 2024/4/11 22:59** @author chenjiacheng* @since 1.0.0*/
public class Log4j2Example {private static final Logger log = LoggerFactory.getLogger(Log4j2Example.class);public static void main(String[] args) {log.trace("hello,world");log.debug("hello,world");log.info("hello,world");log.warn("hello,world");log.error("hello,world");}
}

四、使用MDC完成日志ID

4.1 程序入口处

MDC.put("logId", UUID.randomUUID().toString());

4.2 配置文件配置打印

<PatternLayout pattern="[%d{yyyy-MM-dd HH:mm:ss,SSS}] [%c{1.}::%M] [%t] [%p] [%X{logId}]: %m%n"/>

%x{key}: 用于打印MDC内指定Key的值。

4.3 多线程日志ID传递配置

添加配置: resources/log4j2.component.properties

isThreadContextMapInheritable=true

五. 官网

Slf4j: Slf4j
Log4j2: Log4j2