springboot + slf4j + log4j2

<!--Web依赖-->
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId><exclusions><exclusion><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-logging</artifactId></exclusion></exclusions>
</dependency>
<!-- log4j2-->
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-log4j2</artifactId>
</dependency>

1 依赖如上

2 再配置log4j2.xml

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="Info"><!-- 变量配置 --><Properties><Property name="proj_name">demo</Property><!--由于我是docker部署的项目，挂载日志目录时采用的绝对路径，所以此处也是用的绝对路径。--><Property name="log_path">/log4</Property></Properties><!-- appender配置 --><Appenders><Console name="Console" target="SYSTEM_OUT" immediateFlush="false"><PatternLayout pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} %highlight{%-5level}[%thread] %style{%logger{36}}{cyan} : %msg%n" disableAnsi="false" noConsoleNoAnsi="false"/></Console><!--immediateFlush="false" 普通日志不设置实时写入日志，减少性能开销--><RollingFile name="DailyRollingFileInfo" immediateFlush="false" append="true" fileName="${log_path}/sysLog/${proj_name}-info.log"filePattern="${log_path}/sysLog/${proj_name}-%d{yyyy-MM-dd}-info.log"><ThresholdFilter level="info" onMatch="ACCEPT" onMismatch="DENY"/><PatternLayout pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} [%p] [%thread] %C.%M:%L|%m%n" /><Policies><!--根据filePattern 中的 {yyyy-MM-dd} 设置 一天滚动一次（一天生成一个文件）--><TimeBasedTriggeringPolicy modulate="true" interval="1" /></Policies></RollingFile><!--immediateFlush="true" 报错日志设置实时写入日志--><RollingFile name="DailyRollingFileError" immediateFlush="true" append="true" fileName="${log_path}/errorLog/${proj_name}-error.log"filePattern="${log_path}/errorLog/${proj_name}-%d{yyyy-MM-dd}-error.log"><ThresholdFilter level="error" onMatch="ACCEPT" onMismatch="DENY"/><PatternLayout pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} [%p] [%thread] %C.%M:%L|%m%n" /><Policies><!--根据filePattern 中的 {yyyy-MM-dd} 设置 一天滚动一次（一天生成一个文件）--><TimeBasedTriggeringPolicy modulate="true" interval="1" /></Policies></RollingFile></Appenders><Loggers><Logger name="com.cmnit.micro" level="Info" additivity="false" includeLocation="true"><AppenderRef ref="Console" /><AppenderRef ref="DailyRollingFileInfo" /><AppenderRef ref="DailyRollingFileError" /></Logger><Logger name="org.springframework" level="Info" additivity="false" includeLocation="true"><AppenderRef ref="Console" /><AppenderRef ref="DailyRollingFileInfo" /><AppenderRef ref="DailyRollingFileError" /></Logger><Logger name="org.hibernate" level="Info" additivity="false" includeLocation="true"><AppenderRef ref="Console" /><AppenderRef ref="DailyRollingFileInfo" /><AppenderRef ref="DailyRollingFileError" /></Logger><Logger name="redis.clients" level="Info" additivity="false" includeLocation="true"><AppenderRef ref="Console" /><AppenderRef ref="DailyRollingFileInfo" /><AppenderRef ref="DailyRollingFileError" /></Logger><Root level="Info" includeLocation="true"><AppenderRef ref="Console" /><AppenderRef ref="DailyRollingFileInfo" /><AppenderRef ref="DailyRollingFileError" /></Root></Loggers>
</Configuration>

3 启动项目报错：

Caused by: org.apache.logging.log4j.LoggingException: log4j-slf4j-impl cannot be present with log4j-to-slf4j

解决：翻译过来就是 log4j-slf4j-impl 和 log4j-to-slf4j 不能共存

（但是 log4j-slf4j-impl 是 slf4j 跟 log4j2 的桥接层必须保留。）

利用maven helper 找到依赖去掉 log4j-to-slf4j

去掉后maven变动（spring - jbdc导致）

4 然后再启动项目，还是报错

Exception in thread "main" java.lang.IllegalArgumentException: LoggerFactory is not a Logback LoggerContext but Logback is on the classpath. Either remove Logback or the competing implementation (class org.apache.logging.slf4j.Log4jLoggerFactory loaded from file:/D:/maven-responsity/org/apache/logging/log4j/log4j-slf4j-impl/2.14.1/log4j-slf4j-impl-2.14.1.jar). If you are using WebLogic you will need to add 'org.slf4j' to prefer-application-packages in WEB-INF/weblogic.xml: org.apache.logging.slf4j.Log4jLoggerFactory

解决：去掉依赖 logback （logback 跟 log4j2 冲突，二选一，保留log4j2）

去掉后maven变动（fastDfs依赖导致的）

5 再次启动成功

6 测试结果

直接使用lombok 日志注解 @Slf4j

@Slf4j
@RestController
@RequestMapping("/log4j")
@Api(tags = "Demo:log4j测试")
public class Log4jController {@GetMapping("/log1")@ApiOperation(value = "debug测试")public void log1(){log.info("这是info");log.warn("这是warn");log.error("这是error");}
}

控制台输出：