springboot使用log4j

springboot已经自带了log4j，无法重复引入

1、日志类

注意：

import org.apache.log4j.Logger 【本文使用】
import org.apache.logging.log4j.Logger

package com.timi.t1.utils;

import org.apache.log4j.LogManager;
import org.apache.log4j.Logger;

public class LogUtil {

    private static final Logger logger = LogManager.getLogger(LogUtil.class);

    public static void info(String msg){
        logger.info(msg);
    }

    public static void debug(String msg){
        logger.debug(msg);
    }

    public static void warn(String msg){
        logger.warn(msg);
    }

    public static void error(String msg){
        logger.error(msg);
    }

}

2、配置
src/main/resources/log4j.properties

log4j.rootLogger=ALL,FILE,CONSOLE

log4j.appender.FILE=org.apache.log4j.FileAppender
log4j.appender.FILE.File=./src/logs/${TODAY}.log
log4j.appender.FILE.ImmediateFlush=true
log4j.appender.FILE.Threshold = DEBUG
log4j.appender.FILE.Append=true
log4j.appender.FILE.layout=org.apache.log4j.PatternLayout
log4j.appender.FILE.layout.conversionPattern=%d{ABSOLUTE} %5p %c{1}:%L -22 %m%n

log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender
log4j.appender.CONSOLE.Target=System.out
log4j.appender.CONSOLE.ImmediateFlush=true
log4j.appender.CONSOLE.Threshold = DEBUG
log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout
log4j.appender.CONSOLE.encoding=UTF-8
log4j.appender.CONSOLE.layout.conversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - 22 %m%n

动态文件名配置 ${TODAY}.log

System.setProperty("TODAY", DateUtil.today());

更多：
https://blog.csdn.net/zhanghongzheng3213/article/details/50601678