第一种：基于log4j2.properties

首先pom.xml中导入jar

<dependency>
		  <groupId>org.slf4j</groupId>
		  <artifactId>slf4j-api</artifactId>
		  <version>1.7.21</version>
		</dependency>
		<dependency>
		  <groupId>org.slf4j</groupId>
		  <artifactId>slf4j-log4j12</artifactId>
		  <version>1.7.21</version>
        </dependency>

然后在src/main/resources目录下新建log4j2.properties，该日志文件可以实现，每天新建一个日志文件，前一天的日志以前一天的日期为结尾

### \u8BBE\u7F6E###
log4j.rootLogger = debug,stdout,D,E,I
 
### \u8F93\u51FA\u4FE1\u606F\u5230\u63A7\u5236\u62AC ###
log4j.appender.stdout = org.apache.log4j.ConsoleAppender
log4j.appender.stdout.encoding=utf-8
log4j.appender.stdout.Target = System.out
log4j.appender.stdout.layout = org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern = %d{yyyy-MM-dd HH:mm:ss,SSS} %5p %c{1}:%L - %m%n
 
log4j.appender.D = org.apache.log4j.DailyRollingFileAppender
log4j.appender.D.File = D://logs/debug.log
log4j.appender.file.DatePattern='.'yyyy-MM-dd
log4j.appender.D.Append = true
log4j.appender.D.Threshold = DEBUG
log4j.appender.D.layout = org.apache.log4j.PatternLayout
log4j.appender.D.layout.ConversionPattern =%d{yyyy-MM-dd HH:mm:ss,SSS} %5p %c{1}:%L - %m%n
 
log4j.appender.E = org.apache.log4j.DailyRollingFileAppender
log4j.appender.E.File =D://logs/error.log
log4j.appender.file.DatePattern='.'yyyy-MM-dd
log4j.appender.E.Append = true
log4j.appender.E.Threshold = ERROR
log4j.appender.E.layout = org.apache.log4j.PatternLayout
log4j.appender.E.layout.ConversionPattern = %d{yyyy-MM-dd HH:mm:ss,SSS} %5p %c{1}:%L - %m%n
 
log4j.appender.I = org.apache.log4j.DailyRollingFileAppender
log4j.appender.I.File =D://logs/info.log
log4j.appender.file.DatePattern='.'yyyy-MM-dd
log4j.appender.I.Append = true
log4j.appender.I.Threshold = INFO
log4j.appender.I.layout = org.apache.log4j.PatternLayout
log4j.appender.I.layout.ConversionPattern = %d{yyyy-MM-dd HH:mm:ss,SSS} %5p %c{1}:%L - %m%n

第二种方式：基于log4j2.yml配置文件

首先pom.xml中导入jar

<dependency> <!-- exclude掉spring-boot的默认log配置 -->
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter</artifactId>
			<exclusions>
				<exclusion>
					<groupId>org.springframework.boot</groupId>
					<artifactId>spring-boot-starter-logging</artifactId>
				</exclusion>
			</exclusions>
		</dependency>
		<!-- 引入log4j2依赖 -->
		<!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-log4j2 -->
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-log4j2</artifactId>
			<version>2.0.0.RELEASE</version>
		</dependency>
 
		<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.dataformat/jackson-dataformat-yaml -->
		<dependency><!-- 加上这个才能辨认到log4j2.yml文件 -->
			<groupId>com.fasterxml.jackson.dataformat</groupId>
			<artifactId>jackson-dataformat-yaml</artifactId>
		</dependency>

然后在src/main/resources目录下新建log4j2.yml文件

# 共有8个级别，按照从低到高为：ALL < TRACE < DEBUG < INFO < WARN < ERROR < FATAL < OFF。
Configuration:  
  status: warn  
  monitorInterval: 30
  
  Properties: # 定义全局变量  
    Property: # 缺省配置（用于开发环境）。其他环境需要在VM参数中指定，如下：  
      #测试：-Dlog.level.console=warn -Dlog.level.xjj=trace  
      #生产：-Dlog.level.console=warn -Dlog.level.xjj=info        
      - name: log.level.console  
        value: debug  
      - name: log.sql.level  
        value: trace         
      - name: LOG_HOME  
        value: /bdmsweb-log/logs   
  Appenders:  
    Console:  #输出到控制台  
      name: CONSOLE  
      target: SYSTEM_OUT  
      ThresholdFilter:  
        level: ${sys:log.level.console} # “sys:”表示：如果VM参数中没指定这个变量值，则使用本文件中定义的缺省全局变量值  
        onMatch: ACCEPT  
        onMismatch: DENY  
      PatternLayout:  
        pattern: "%d{yyyy-MM-dd HH:mm:ss,SSS} %5p %c{1}:%L - %m%n"  
    RollingFile: # 输出到文件，超过128MB归档  
      - name: info    
        ignoreExceptions: false  
        fileName: ${LOG_HOME}/${date:yyyy-MM}/${date:yyyy-MM-dd}/info.log  
        filePattern: "${LOG_HOME}/${date:yyyy-MM}/info-%d{yyyy-MM-dd}-%i.log.gz"  
        ThresholdFilter:  
          level: info
          onMatch: ACCEPT  
          onMismatch: DENY 
        PatternLayout:  
          pattern: "%d{yyyy-MM-dd HH:mm:ss,SSS} %5p %c{1}:%L - %m%n"  
        Policies:  
          SizeBasedTriggeringPolicy:  
            size: "128 MB"  
        DefaultRolloverStrategy:  
          max: 1000  
      - name: debug   
        ignoreExceptions: false  
        fileName: ${LOG_HOME}/${date:yyyy-MM}/${date:yyyy-MM-dd}/debug.log  
        filePattern: "${LOG_HOME}/$${date:yyyy-MM}/debug-%d{yyyy-MM-dd}-%i.log.gz" 
        ThresholdFilter:  
          level: debug
          onMatch: ACCEPT  
          onMismatch: DENY  
        PatternLayout:  
          pattern: "%d{yyyy-MM-dd HH:mm:ss,SSS} %5p %c{1}:%L - %m%n"  
        Policies:  
          SizeBasedTriggeringPolicy:  
            size: "128 MB"  
        DefaultRolloverStrategy:  
          max: 1000  
      - name: error  
        ignoreExceptions: false  
        fileName: ${LOG_HOME}/${date:yyyy-MM}/${date:yyyy-MM-dd}/error.log  
        filePattern: "${LOG_HOME}/$${date:yyyy-MM}/error-%d{yyyy-MM-dd}-%i.log.gz"  
        ThresholdFilter:  
          level: error
          onMatch: ACCEPT  
          onMismatch: DENY
        PatternLayout:  
          pattern: "%d{yyyy-MM-dd HH:mm:ss,SSS} %5p %c{1}:%L - %m%n"  
        Policies:  
          SizeBasedTriggeringPolicy:  
            size: "128 MB"  
        DefaultRolloverStrategy:  
          max: 1000               
  Loggers:  
    Root:  
      level: info  
      AppenderRef:  
        - ref: CONSOLE
        - ref: info  
        - ref: debug  
        - ref: error  
    Logger: # 为com.xjj包配置特殊的Log级别，方便调试  
      - name: cnki.bdms.module.search.dal
        additivity: true  
        level: ${sys:log.sql.level}  
        AppenderRef:
          - ref: info    
          - ref: debug 
          - ref: error 
          - ref: CONSOLE

最后在application.yml中添加配置

logging:
  config: classpath:log4j2.yml

完成以上配置之后 运行项目，便可以在D盘/bdmsweb-log/logs 目录下看到以日期为区分的日志文件