问题背景

使用 Maven 构建 SpringBoot 项目里面集成 Dubbo 和 zookeeper 时候发生了以下问题

错误信息

SLF4J: Actual binding is of type [org.slf4j.impl.Reload4jLoggerFactory]
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.Reload4jLoggerFactory loaded from file:/D:/repo/org/slf4j/slf4j-reload4j/1.7.36/slf4j-reload4j-1.7.36.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.Reload4jLoggerFactory
    at org.springframework.util.Assert.instanceCheckFailed(Assert.java:702)
    at org.springframework.util.Assert.isInstanceOf(Assert.java:621)
    at org.springframework.boot.logging.logback.LogbackLoggingSystem.getLoggerContext(LogbackLoggingSystem.java:294)
    at org.springframework.boot.logging.logback.LogbackLoggingSystem.beforeInitialize(LogbackLoggingSystem.java:118)
    at org.springframework.boot.context.logging.LoggingApplicationListener.onApplicationStartingEvent(LoggingApplicationListener.java:232)
    at org.springframework.boot.context.logging.LoggingApplicationListener.onApplicationEvent(LoggingApplicationListener.java:213)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:176)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:169)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:143)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:131)
    at org.springframework.boot.context.event.EventPublishingRunListener.starting(EventPublishingRunListener.java:79)
    at org.springframework.boot.SpringApplicationRunListeners.lambda$starting$0(SpringApplicationRunListeners.java:56)
    at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
    at org.springframework.boot.SpringApplicationRunListeners.doWithListeners(SpringApplicationRunListeners.java:120)
    at org.springframework.boot.SpringApplicationRunListeners.starting(SpringApplicationRunListeners.java:56)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:299)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1306)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1295)
    at com.rb.service.DubboApplication.main(DubboApplication.java:15)

原因分析

项目的日志框架在选择上 出现了多个 bindings， 可以利用 mvn dependency:tree 查询依赖树

解决方案

zookeeper 的maven 依赖里面排除 Reload4j 日志框架

<dependency>
      <groupId>org.apache.dubbo</groupId>
      <artifactId>dubbo-dependencies-zookeeper</artifactId>
      <type>pom</type>
      <exclusions>
        <exclusion>
          <groupId>org.slf4j</groupId>
          <artifactId>slf4j-reload4j</artifactId>
        </exclusion>
      </exclusions>
    </dependency>