Spring Boot 整合 Log4j2 不起作用

现象

pom文件中引入了log4j2。

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-log4j2</artifactId>
    <version>2.6.0</version>
</dependency>

启动项目时提示使用了logback。

SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/C:/maven/repository/ch/qos/logback/logback-classic/1.2.3/logback-classic-1.2.3.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/C:/maven/repository/org/apache/logging/log4j/log4j-slf4j-impl/2.13.3/log4j-slf4j-impl-2.13.3.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
SLF4J: Actual binding is of type [ch.qos.logback.classic.util.ContextSelectorStaticBinder]

原因

因为项目是web项目，所以引入了spring-boot-starter-web，但spring-boot-starter-web包括了spring-boot-starter-logging依赖，而spring-boot-starter-logging里面包含了logback的依赖导致了此问题。

解决

将spring-boot-starter-logging排除即可。

重新打包启动无提示报错。

<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>