彻底解决SLF4J: Class path contains multiple SLF4J bindings.

springboot项目跑起来后，一直报SLF4J包冲突，看着很烦。

Connected to the target VM, address: '127.0.0.1:64448', transport: 'socket'
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/D:/maven-3.3.3/m2/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:/D:/maven-3.3.3/m2/repository/org/slf4j/slf4j-log4j12/1.7.25/slf4j-log4j12-1.7.25.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]

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v2.1.0.RELEASE)

这个要解决一下

既然是冲突，那可能就是项目中依赖了多个不同版本的slf4j类库，那如何分析到底是哪几个类库依赖了slf4j呢？我们可以使用dependency:tree命令：

$ mvn dependency:tree

看到dubbo中slf4j冲突，我们排除一下就好了

   com.alibaba
   dubbo
   3.8.4
   
      
         org.springframework
         spring
      
              
              org.slf4j
              slf4j-log4j12
          
   
 

试一下干净清爽了