org.springframework.web.SpringServletContainerInitializer cannot be cast to javax.servlet.ServletCon

严重: A child container failed during start
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].StandardContext[]]
at java.util.concurrent.FutureTask.report(FutureTask.java:122)
at java.util.concurrent.FutureTask.get(FutureTask.java:188)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1123)
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:800)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
at java.util.concurrent.FutureTask.run(FutureTask.java:262)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].StandardContext[]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
... 6 more
Caused by: java.lang.ClassCastException: org.springframework.web.SpringServletContainerInitializer cannot be cast to javax.servlet.ServletContainerInitializer
at org.apache.catalina.startup.ContextConfig.getServletContainerInitializer(ContextConfig.java:1670)
at org.apache.catalina.startup.ContextConfig.getServletContainerInitializers(ContextConfig.java:1652)
at org.apache.catalina.startup.ContextConfig.processServletContainerInitializers(ContextConfig.java:1562)
at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1270)
at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:878)
at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:376)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5322)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
... 6 more

​此类问题的多半是web.xml配置有问题，或者是pom.xml中的jar包冲突。

根据关键信息org.springframework.web.SpringServletContainerInitializer cannot be cast to javax.servlet.ServletContainerInitializer

得知基本是ServletContainerInitializer类版本不一致造成的。

经过排查，是由于我在pom.xml中引入的javaee jar包有问题

<dependency>
<groupId>javax</groupId>
<artifactId>javaee-api</artifactId>
<version>7.0</version>
</dependency>

此处的javaee-api与tomcat的javaee-api冲突

所以可以采取删除这个jar包引用，或者加上关键字

<dependency>
<groupId>javax</groupId>
<artifactId>javaee-api</artifactId>
<scope>provided</scope>
<version>7.0</version>
</dependency>

这个关键字的设置是起到定义jar包生存周期的作用，这个设置认为在环境中已经存在这个jar包了就不再部署了。

所以这个关键字对于解决jar包冲突能起到很好的作用。