SpringBoot在Eclipse内能够运行,但是部署在Tomcat8上启动时会有一个logback的异常

Question

新开发一个项目,我使用了Springboot作为框架,在项目开发期间我一直使用Eclipse来进行测试,期间一切正常,在近日准备部署到本地的Tomcat8 上供客户端开发的时候发现了这个问题,具体异常如下: 23-May-2017 14:32:20.119 严重 [localhost-startStop-1] org.apache.catalina.core.ContainerBase.addChildInternal ContainerBase.addChild: start: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/ucwapi]] at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167) at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:752) at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:728) at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:734) at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:952) at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:1823) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:745) 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 file:/C:/server/apache-tomcat-8.5.15/webapps/ucwapi/WEB-INF/lib/log4j-slf4j-impl-2.4.1.jar). If you are using WebLogic you will need to add 'org.slf4j' to prefer-application-packages in WEB-INF/weblogic.xml Object of class [org.apache.logging.slf4j.Log4jLoggerFactory] must be an instance of class ch.qos.logback.classic.LoggerContext at org.springframework.util.Assert.isInstanceOf(Assert.java:346) at org.springframework.boot.logging.logback.LogbackLoggingSystem.getLoggerContext(LogbackLoggingSystem.java:221) at org.springframework.boot.logging.logback.LogbackLoggingSystem.getLogger(LogbackLoggingSystem.java:213) at org.springframework.boot.logging.logback.LogbackLoggingSystem.beforeInitialize(LogbackLoggingSystem.java:98) at org.springframework.boot.logging.LoggingApplicationListener.onApplicationStartedEvent(LoggingApplicationListener.java:215) at org.springframework.boot.logging.LoggingApplicationListener.onApplicationEvent(LoggingApplicationListener.java:197) at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:166) at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:138) at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:121) at org.springframework.boot.context.event.EventPublishingRunListener.publishEvent(EventPublishingRunListener.java:111) at org.springframework.boot.context.event.EventPublishingRunListener.started(EventPublishingRunListener.java:60) at org.springframework.boot.SpringApplicationRunListeners.started(SpringApplicationRunListeners.java:48) at org.springframework.boot.SpringApplication.run(SpringApplication.java:303) at org.springframework.boot.context.web.SpringBootServletInitializer.run(SpringBootServletInitializer.java:149) at org.springframework.boot.context.web.SpringBootServletInitializer.createRootApplicationContext(SpringBootServletInitializer.java:129) at org.springframework.boot.context.web.SpringBootServletInitializer.onStartup(SpringBootServletInitializer.java:85) at org.springframework.web.SpringServletContainerInitializer.onStartup(SpringServletContainerInitializer.java:169) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5196) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) ... 10 more 23-May-2017 14:32:20.120 严重 [localhost-startStop-1] org.apache.catalina.startup.HostConfig.deployWAR Error deploying web application archive [C:\server\apache-tomcat-8.5.15\webapps\ucwapi.war] java.lang.IllegalStateException: ContainerBase.addChild: start: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/ucwapi]] at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:756) at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:728) at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:734) at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:952) at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:1823) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:745) Springboot 版本为1.3.5logback版本为1.1.7

Answer 1

Tomcat7.0 升级至8.0 问题解决

Answer 2

原因：ClassLoader 的关系，IDE中的ClassLoader 实现与 Spring Boot JarLauncher 不同，因此，加载了不同的jar。log4j-slf4j 与logback 均为 slf4j-api的实现，所以冲突了。

解决方法：移除 log4j-slf4j 依赖（通过Maven)