今天在springboot项目中替换log4j2日志的时候遇见的问题，闲话不多说。
错误日志
Logging system failed to initialize using configuration from 'classpath:log4j2-dev.xml' java.lang.IllegalStateException: Logback configuration error detected: ERROR in ch.qos.logback.core.joran.spi.Interpreter@3:16 - no applicable action for [appenders], current ElementPath is [[configuration][appenders]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@4:67 - no applicable action for [Console], current ElementPath is [[configuration][appenders][Console]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@5:96 - no applicable action for [PatternLayout], current ElementPath is [[configuration][appenders][Console][PatternLayout]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@10:119 - no applicable action for [RollingFile], current ElementPath is [[configuration][appenders][RollingFile]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@11:96 - no applicable action for [PatternLayout], current ElementPath is [[configuration][appenders][RollingFile][PatternLayout]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@12:23 - no applicable action for [Policies], current ElementPath is [[configuration][appenders][RollingFile][Policies]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@13:45 - no applicable action for [TimeBasedTriggeringPolicy], current ElementPath is [[configuration][appenders][RollingFile][Policies][TimeBasedTriggeringPolicy]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@14:57 - no applicable action for [SizeBasedTriggeringPolicy], current ElementPath is [[configuration][appenders][RollingFile][Policies][SizeBasedTriggeringPolicy]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@16:48 - no applicable action for [DefaultRolloverStrategy], current ElementPath is [[configuration][appenders][RollingFile][DefaultRolloverStrategy]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@21:79 - no applicable action for [RollingFile], current ElementPath is [[configuration][appenders][RollingFile]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@22:96 - no applicable action for [PatternLayout], current ElementPath is [[configuration][appenders][RollingFile][PatternLayout]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@23:23 - no applicable action for [Policies], current ElementPath is [[configuration][appenders][RollingFile][Policies]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@24:45 - no applicable action for [TimeBasedTriggeringPolicy], current ElementPath is [[configuration][appenders][RollingFile][Policies][TimeBasedTriggeringPolicy]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@25:57 - no applicable action for [SizeBasedTriggeringPolicy], current ElementPath is [[configuration][appenders][RollingFile][Policies][SizeBasedTriggeringPolicy]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@27:48 - no applicable action for [DefaultRolloverStrategy], current ElementPath is [[configuration][appenders][RollingFile][DefaultRolloverStrategy]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@28:79 - no applicable action for [ThresholdFilter], current ElementPath is [[configuration][appenders][RollingFile][ThresholdFilter]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@32:14 - no applicable action for [loggers], current ElementPath is [[configuration][loggers]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@36:64 - no applicable action for [logger], current ElementPath is [[configuration][loggers][logger]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@37:42 - no applicable action for [appender-ref], current ElementPath is [[configuration][loggers][logger][appender-ref]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@38:43 - no applicable action for [appender-ref], current ElementPath is [[configuration][loggers][logger][appender-ref]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@39:44 - no applicable action for [appender-ref], current ElementPath is [[configuration][loggers][logger][appender-ref]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@43:77 - no applicable action for [logger], current ElementPath is [[configuration][loggers][logger]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@44:42 - no applicable action for [appender-ref], current ElementPath is [[configuration][loggers][logger][appender-ref]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@50:28 - no applicable action for [root], current ElementPath is [[configuration][loggers][root]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@52:42 - no applicable action for [appender-ref], current ElementPath is [[configuration][loggers][root][appender-ref]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@53:43 - no applicable action for [appender-ref], current ElementPath is [[configuration][loggers][root][appender-ref]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@54:44 - no applicable action for [appender-ref], current ElementPath is [[configuration][loggers][root][appender-ref]] at org.springframework.boot.logging.logback.LogbackLoggingSystem.loadConfiguration(LogbackLoggingSystem.java:162) at org.springframework.boot.logging.AbstractLoggingSystem.initializeWithSpecificConfig(AbstractLoggingSystem.java:66) at org.springframework.boot.logging.AbstractLoggingSystem.initialize(AbstractLoggingSystem.java:56) at org.springframework.boot.logging.logback.LogbackLoggingSystem.initialize(LogbackLoggingSystem.java:114) at org.springframework.boot.logging.LoggingApplicationListener.initializeSystem(LoggingApplicationListener.java:309) at org.springframework.boot.logging.LoggingApplicationListener.initialize(LoggingApplicationListener.java:277) at org.springframework.boot.logging.LoggingApplicationListener.onApplicationEnvironmentPreparedEvent(LoggingApplicationListener.java:240) at org.springframework.boot.logging.LoggingApplicationListener.onApplicationEvent(LoggingApplicationListener.java:213) 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.environmentPrepared(EventPublishingRunListener.java:74) at org.springframework.boot.SpringApplicationRunListeners.environmentPrepared(SpringApplicationRunListeners.java:54) at org.springframework.boot.SpringApplication.prepareEnvironment(SpringApplication.java:325) at org.springframework.boot.SpringApplication.run(SpringApplication.java:296) at org.springframework.boot.test.context.SpringBootContextLoader.loadContext(SpringBootContextLoader.java:121) at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContextInternal(DefaultCacheAwareContextLoaderDelegate.java:98) at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:116) at org.springframework.test.context.support.DefaultTestContext.getApplicationContext(DefaultTestContext.java:83) at org.springframework.test.context.web.ServletTestExecutionListener.setUpRequestContextIfNecessary(ServletTestExecutionListener.java:189) at org.springframework.test.context.web.ServletTestExecutionListener.prepareTestInstance(ServletTestExecutionListener.java:131) at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:230) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:228) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:287) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:289) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:247) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:94) at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290) at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71) at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288) at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58) at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268) at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61) at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70) at org.junit.runners.ParentRunner.run(ParentRunner.java:363) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:191) at org.junit.runner.JUnitCore.run(JUnitCore.java:137) at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68) at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47) at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242) at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70) java.lang.IllegalStateException: Failed to load ApplicationContext at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:124) at org.springframework.test.context.support.DefaultTestContext.getApplicationContext(DefaultTestContext.java:83) at org.springframework.test.context.web.ServletTestExecutionListener.setUpRequestContextIfNecessary(ServletTestExecutionListener.java:189) at org.springframework.test.context.web.ServletTestExecutionListener.prepareTestInstance(ServletTestExecutionListener.java:131) at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:230) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:228) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:287) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:289) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:247) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:94) at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290) at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71) at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288) at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58) at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268) at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61) at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70) at org.junit.runners.ParentRunner.run(ParentRunner.java:363) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:191) at org.junit.runner.JUnitCore.run(JUnitCore.java:137) at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68) at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47) at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242) at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70) Caused by: java.lang.IllegalStateException: java.lang.IllegalStateException: Logback configuration error detected: ERROR in ch.qos.logback.core.joran.spi.Interpreter@3:16 - no applicable action for [appenders], current ElementPath is [[configuration][appenders]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@4:67 - no applicable action for [Console], current ElementPath is [[configuration][appenders][Console]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@5:96 - no applicable action for [PatternLayout], current ElementPath is [[configuration][appenders][Console][PatternLayout]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@10:119 - no applicable action for [RollingFile], current ElementPath is [[configuration][appenders][RollingFile]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@11:96 - no applicable action for [PatternLayout], current ElementPath is [[configuration][appenders][RollingFile][PatternLayout]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@12:23 - no applicable action for [Policies], current ElementPath is [[configuration][appenders][RollingFile][Policies]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@13:45 - no applicable action for [TimeBasedTriggeringPolicy], current ElementPath is [[configuration][appenders][RollingFile][Policies][TimeBasedTriggeringPolicy]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@14:57 - no applicable action for [SizeBasedTriggeringPolicy], current ElementPath is [[configuration][appenders][RollingFile][Policies][SizeBasedTriggeringPolicy]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@16:48 - no applicable action for [DefaultRolloverStrategy], current ElementPath is [[configuration][appenders][RollingFile][DefaultRolloverStrategy]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@21:79 - no applicable action for [RollingFile], current ElementPath is [[configuration][appenders][RollingFile]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@22:96 - no applicable action for [PatternLayout], current ElementPath is [[configuration][appenders][RollingFile][PatternLayout]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@23:23 - no applicable action for [Policies], current ElementPath is [[configuration][appenders][RollingFile][Policies]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@24:45 - no applicable action for [TimeBasedTriggeringPolicy], current ElementPath is [[configuration][appenders][RollingFile][Policies][TimeBasedTriggeringPolicy]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@25:57 - no applicable action for [SizeBasedTriggeringPolicy], current ElementPath is [[configuration][appenders][RollingFile][Policies][SizeBasedTriggeringPolicy]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@27:48 - no applicable action for [DefaultRolloverStrategy], current ElementPath is [[configuration][appenders][RollingFile][DefaultRolloverStrategy]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@28:79 - no applicable action for [ThresholdFilter], current ElementPath is [[configuration][appenders][RollingFile][ThresholdFilter]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@32:14 - no applicable action for [loggers], current ElementPath is [[configuration][loggers]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@36:64 - no applicable action for [logger], current ElementPath is [[configuration][loggers][logger]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@37:42 - no applicable action for [appender-ref], current ElementPath is [[configuration][loggers][logger][appender-ref]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@38:43 - no applicable action for [appender-ref], current ElementPath is [[configuration][loggers][logger][appender-ref]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@39:44 - no applicable action for [appender-ref], current ElementPath is [[configuration][loggers][logger][appender-ref]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@43:77 - no applicable action for [logger], current ElementPath is [[configuration][loggers][logger]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@44:42 - no applicable action for [appender-ref], current ElementPath is [[configuration][loggers][logger][appender-ref]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@50:28 - no applicable action for [root], current ElementPath is [[configuration][loggers][root]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@52:42 - no applicable action for [appender-ref], current ElementPath is [[configuration][loggers][root][appender-ref]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@53:43 - no applicable action for [appender-ref], current ElementPath is [[configuration][loggers][root][appender-ref]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@54:44 - no applicable action for [appender-ref], current ElementPath is [[configuration][loggers][root][appender-ref]] at org.springframework.boot.logging.LoggingApplicationListener.initializeSystem(LoggingApplicationListener.java:316) at org.springframework.boot.logging.LoggingApplicationListener.initialize(LoggingApplicationListener.java:277) at org.springframework.boot.logging.LoggingApplicationListener.onApplicationEnvironmentPreparedEvent(LoggingApplicationListener.java:240) at org.springframework.boot.logging.LoggingApplicationListener.onApplicationEvent(LoggingApplicationListener.java:213) 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.environmentPrepared(EventPublishingRunListener.java:74) at org.springframework.boot.SpringApplicationRunListeners.environmentPrepared(SpringApplicationRunListeners.java:54) at org.springframework.boot.SpringApplication.prepareEnvironment(SpringApplication.java:325) at org.springframework.boot.SpringApplication.run(SpringApplication.java:296) at org.springframework.boot.test.context.SpringBootContextLoader.loadContext(SpringBootContextLoader.java:121) at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContextInternal(DefaultCacheAwareContextLoaderDelegate.java:98) at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:116) ... 24 more Caused by: java.lang.IllegalStateException: Logback configuration error detected: ERROR in ch.qos.logback.core.joran.spi.Interpreter@3:16 - no applicable action for [appenders], current ElementPath is [[configuration][appenders]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@4:67 - no applicable action for [Console], current ElementPath is [[configuration][appenders][Console]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@5:96 - no applicable action for [PatternLayout], current ElementPath is [[configuration][appenders][Console][PatternLayout]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@10:119 - no applicable action for [RollingFile], current ElementPath is [[configuration][appenders][RollingFile]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@11:96 - no applicable action for [PatternLayout], current ElementPath is [[configuration][appenders][RollingFile][PatternLayout]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@12:23 - no applicable action for [Policies], current ElementPath is [[configuration][appenders][RollingFile][Policies]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@13:45 - no applicable action for [TimeBasedTriggeringPolicy], current ElementPath is [[configuration][appenders][RollingFile][Policies][TimeBasedTriggeringPolicy]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@14:57 - no applicable action for [SizeBasedTriggeringPolicy], current ElementPath is [[configuration][appenders][RollingFile][Policies][SizeBasedTriggeringPolicy]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@16:48 - no applicable action for [DefaultRolloverStrategy], current ElementPath is [[configuration][appenders][RollingFile][DefaultRolloverStrategy]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@21:79 - no applicable action for [RollingFile], current ElementPath is [[configuration][appenders][RollingFile]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@22:96 - no applicable action for [PatternLayout], current ElementPath is [[configuration][appenders][RollingFile][PatternLayout]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@23:23 - no applicable action for [Policies], current ElementPath is [[configuration][appenders][RollingFile][Policies]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@24:45 - no applicable action for [TimeBasedTriggeringPolicy], current ElementPath is [[configuration][appenders][RollingFile][Policies][TimeBasedTriggeringPolicy]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@25:57 - no applicable action for [SizeBasedTriggeringPolicy], current ElementPath is [[configuration][appenders][RollingFile][Policies][SizeBasedTriggeringPolicy]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@27:48 - no applicable action for [DefaultRolloverStrategy], current ElementPath is [[configuration][appenders][RollingFile][DefaultRolloverStrategy]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@28:79 - no applicable action for [ThresholdFilter], current ElementPath is [[configuration][appenders][RollingFile][ThresholdFilter]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@32:14 - no applicable action for [loggers], current ElementPath is [[configuration][loggers]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@36:64 - no applicable action for [logger], current ElementPath is [[configuration][loggers][logger]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@37:42 - no applicable action for [appender-ref], current ElementPath is [[configuration][loggers][logger][appender-ref]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@38:43 - no applicable action for [appender-ref], current ElementPath is [[configuration][loggers][logger][appender-ref]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@39:44 - no applicable action for [appender-ref], current ElementPath is [[configuration][loggers][logger][appender-ref]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@43:77 - no applicable action for [logger], current ElementPath is [[configuration][loggers][logger]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@44:42 - no applicable action for [appender-ref], current ElementPath is [[configuration][loggers][logger][appender-ref]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@50:28 - no applicable action for [root], current ElementPath is [[configuration][loggers][root]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@52:42 - no applicable action for [appender-ref], current ElementPath is [[configuration][loggers][root][appender-ref]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@53:43 - no applicable action for [appender-ref], current ElementPath is [[configuration][loggers][root][appender-ref]] ERROR in ch.qos.logback.core.joran.spi.Interpreter@54:44 - no applicable action for [appender-ref], current ElementPath is [[configuration][loggers][root][appender-ref]] at org.springframework.boot.logging.logback.LogbackLoggingSystem.loadConfiguration(LogbackLoggingSystem.java:162) at org.springframework.boot.logging.AbstractLoggingSystem.initializeWithSpecificConfig(AbstractLoggingSystem.java:66) at org.springframework.boot.logging.AbstractLoggingSystem.initialize(AbstractLoggingSystem.java:56) at org.springframework.boot.logging.logback.LogbackLoggingSystem.initialize(LogbackLoggingSystem.java:114) at org.springframework.boot.logging.LoggingApplicationListener.initializeSystem(LoggingApplicationListener.java:309) ... 38 more Disconnected from the target VM, address: '127.0.0.1:65035', transport: 'socket' Process finished with exit code -1
首先我们看上面的错误日志
Logging system failed to initialize using configuration from 'classpath:log4j2-dev.xml' java.lang.IllegalStateException: Logback configuration error detected:
如果只看这两句的话我们可能会认为是我们的日志文件log4j2-dev.xml配置错了，或者路径找不到，其实不然。正解是我们pom文件配置的有问题，jar包存在冲突，下面来看下我们的pom文件吧
pom.xml
org.springframework.boot spring-boot-starter-jdbc org.springframework.boot spring-boot-starter-web org.springframework.boot spring-boot-starter-log4j2
上面的pom文件是最初报错时的配置文件，看上面的配置文件貌似没有问题，我们需使用log4j2日志的starter也已经引入了，但是这里我们需要注意一点就是我们在引入spring-boot-starter-web包的时候他里面默认使用了logback日志，这样就会产生日志包的冲突，其实不只是starter-web包默认引入的logback还有很多的包默认引入的logback包，看下图
上图中是这个pom文件的jiar包结构示意图，log4j2部分就是我们新引入的spring-boot-starter-log4j2包，上图中我通过黄线画出了现在系统中所有logback的引入，可以看出所有引用，这里涉及到几个包，分别是web包，mybatis包，jdbc包。那我们现在要解决jar包冲突的问题是不是需要每个包下都排除默认引用的logger日志呢，理论上是完全没有问题的，但是那样岂不是很费事，2种解决办法。
解决办法1
统一排除
org.springframework.boot spring-boot-starter org.springframework.boot spring-boot-starter-logging
解决办法2
那我只导用了web包，不想导入spring-boot-starter能不能解决呢？
答 ： 能
org.springframework.boot spring-boot-starter-web org.springframework.boot spring-boot-starter-logging
看见第二个解决办法，问题是不是来了。很多包都默认使用的logback,你单独排除了web包是不是还会出现这个问题，
答 ： 是的会出现，这里就需要知道pom文件的加载顺序了，pom文件的加载顺序也是从上至下执行，那么我们就需要把web包放到pom文件中的第一位，在向下执行的时候也会排除所有的默认logger了。
上面就是两种解决办法。希望能给大家一个参考，也希望大家多多支持脚本之家。