Springboot启动报错:LoggerFactory is not a Logback LoggerContext but Logback is on the classpath.

1.问题描述

启动WebApplication就会报错

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.slf4j.impl.Log4jLoggerFactory loaded from file:/E:/Tools/apache-maven-3.3.9/Repository/org/slf4j/slf4j-log4j12/1.7.25/slf4j-log4j12-1.7.25.jar). If you are using WebLogic you will need to add 'org.slf4j' to prefer-application-packages in WEB-INF/weblogic.xml: org.slf4j.impl.Log4jLoggerFactory
	at org.springframework.util.Assert.instanceCheckFailed(Assert.java:637)
	at org.springframework.util.Assert.isInstanceOf(Assert.java:537)
	at org.springframework.boot.logging.logback.LogbackLoggingSystem.getLoggerContext(LogbackLoggingSystem.java:286)
	at org.springframework.boot.logging.logback.LogbackLoggingSystem.beforeInitialize(LogbackLoggingSystem.java:102)
	at org.springframework.boot.context.logging.LoggingApplicationListener.onApplicationStartingEvent(LoggingApplicationListener.java:191)
	at org.springframework.boot.context.logging.LoggingApplicationListener.onApplicationEvent(LoggingApplicationListener.java:170)

2.原因

原因报错写的很清楚：

LoggerFactory is not a Logback LoggerContext but Logback is on the classpath. Either remove Logback or the competing implementation

由于默认组件logback，会和当前使用的log4j组件冲突。

3.解决：在pom中将默认日志组件清除

原始

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-web</artifactId>
</dependency>

修改

<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>