嚴重: A child container failed during start
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/smallclaim]]
at java.util.concurrent.FutureTask.report(Unknown Source)
at java.util.concurrent.FutureTask.get(Unknown Source)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1239)
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:819)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1700)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1690)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/smallclaim]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:162)
... 6 more
Caused by: java.lang.NoClassDefFoundError: ServletContextEvent
at java.lang.Class.getDeclaredMethods0(Native Method)
at java.lang.Class.privateGetDeclaredMethods(Unknown Source)
at java.lang.Class.getDeclaredMethods(Unknown Source)
at org.apache.catalina.util.Introspection.getDeclaredMethods(Introspection.java:127)
at org.apache.catalina.startup.WebAnnotationSet.loadMethodsAnnotation(WebAnnotationSet.java:283)
at org.apache.catalina.startup.WebAnnotationSet.loadApplicationListenerAnnotations(WebAnnotationSet.java:88)
at org.apache.catalina.startup.WebAnnotationSet.loadApplicationAnnotations(WebAnnotationSet.java:65)
at org.apache.catalina.startup.ContextConfig.applicationAnnotationsConfig(ContextConfig.java:417)
at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:890)
at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:388)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)
at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5527)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
... 6 more
Caused by: java.lang.ClassNotFoundException: ServletContextEvent
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1907)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1750)

... 20 more

找了很多網上的資料，沒解決我的問題

最後發現，僅限於我的問題：

我是從svn上直接拉程式碼下來的，然後就直接跑，沒跑起來

經指點，

要先建立一個專案 dynamic web project module version 選2.5
新建資料夾 src config 從之前的專案裡拷貝 WEB-INF裡只保留 lib資料夾 把之前的jar包複製進去

然後跑，就行了

分析原因：

之前人上傳的專案有問題，不能直接跑，包括前面做前端專案也是這樣，前人上傳專案很不上心，煩惱

新建一個專案，它會自動生成很多配置檔案，就像vue裡的package.json  直接安裝即可，所以專案的完整性很關鍵

這次替換專案的資料夾後，web-inf裡的lib下是空的，要記得把jar包複製進去