SLF4J: Actual binding is of type [org.apache.logging.slf4j.Log4jLoggerFactory]

slfj4依赖冲突

产生情况

在使用

 <plugin>
      <groupId>org.springframework.bootgroupId>
       <artifactId>spring-boot-maven-pluginartifactId>
       <version>1.4.2.RELEASEversion>
 plugin>

对spring boot项目进行打包时候，1.4.2版本spring boot 插件是以为可以支持jsp资源访问，发生依赖问题，项目不能正常启动。但是换上高版本就不会发生这个问题。真是奇葩

以下是报错信息

SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
SLF4J: Actual binding is of type [org.apache.logging.slf4j.Log4jLoggerFactory]
Exception in thread "main" java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:48)
    at org.springframework.boot.loader.Launcher.launch(Launcher.java:87)
    at org.springframework.boot.loader.Launcher.launch(Launcher.java:50)
    at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:58)
Caused by: 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 jar:file:/home/CubeStorageSystem-0.1-SNAPSHOT.jar!/BOOT-INF/lib/log4j-slf4j-impl-2.7.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
    at org.springframework.util.Assert.instanceCheckFailed(Assert.java:389)
    at org.springframework.util.Assert.isInstanceOf(Assert.java:327)
    at org.springframework.boot.logging.logback.LogbackLoggingSystem.getLoggerContext(LogbackLoggingSystem.java:274)
    at org.springframework.boot.logging.logback.LogbackLoggingSystem.beforeInitialize(LogbackLoggingSystem.java:98)
    at org.springframework.boot.logging.LoggingApplicationListener.onApplicationStartingEvent(LoggingApplicationListener.java:230)
    at org.springframework.boot.logging.LoggingApplicationListener.onApplicationEvent(LoggingApplicationListener.java:209)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:122)
    at org.springframework.boot.context.event.EventPublishingRunListener.starting(EventPublishingRunListener.java:69)
    at org.springframework.boot.SpringApplicationRunListeners.starting(SpringApplicationRunListeners.java:48)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:292)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1118)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1107)
    at cube.Application.main(Application.java:23)
    ... 8 more

解决方案

查阅资料，原因是因为在竞争slfj的依赖，低版本中找不到实现类。

引入以下依赖即可

<dependency>
   <groupId>org.apache.logging.log4jgroupId>
    <artifactId>log4j-slf4j-implartifactId>
    <version>2.9.1version>
dependency>

一般引入以下日志包也可能解决问题

  
        <dependency>
            <groupId>org.slf4jgroupId>
            <artifactId>slf4j-log4j12artifactId>
            <version>1.7.2version>
        dependency>
        
        <dependency>
            <groupId>org.slf4jgroupId>
            <artifactId>log4j-over-slf4jartifactId>
            <version>1.7.25version>
        dependency>
        <dependency>
            <groupId>org.apache.commonsgroupId>
            <artifactId>commons-lang3artifactId>
            <version>3.0version>
        dependency>
        
        <dependency>
            <groupId>org.slf4jgroupId>
            <artifactId>slf4j-apiartifactId>
            <version>1.7.25version>
        dependency>
        
        <dependency>
            <groupId>log4jgroupId>
            <artifactId>log4jartifactId>
            <version>1.2.17version>
        dependency>

总结

感觉spring boot对jsp的支持不是太好，高版本对jsp有完全访问不到，低版本中又是各种问题，毕竟spring boot不建议使用jsp，也没办法，有时候又必须要使用到jsp。只能这样了