严重: A child container failed during start java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component

自己写了个最简单的springMVC项目练练手，没有用maven，在WebContent中新建了lib文件夹，将jar包复制到这里面，然后add to build path到项目里。

启动Tomcat，报错，启动不起来。在网页中运行localhost:8080发现Tomcat页面是可以打开的。

报错内容如下：

 严重: A child container failed during start
 java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/zhang]]
     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:799)
     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[Catalina].StandardHost[localhost].StandardContext[/zhang]]
     at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
     ... 6 more
 Caused by: java.lang.NoClassDefFoundError: org/springframework/web/context/WebApplicationContext
     at java.lang.Class.getDeclaredFields0(Native Method)
     at java.lang.Class.privateGetDeclaredFields(Class.java:2436)
     at java.lang.Class.getDeclaredFields(Class.java:1806)
     at org.apache.catalina.util.Introspection.getDeclaredFields(Introspection.java:106)
     at org.apache.catalina.startup.WebAnnotationSet.loadFieldsAnnotation(WebAnnotationSet.java:261)
     at org.apache.catalina.startup.WebAnnotationSet.loadApplicationServletAnnotations(WebAnnotationSet.java:140)
     at org.apache.catalina.startup.WebAnnotationSet.loadApplicationAnnotations(WebAnnotationSet.java:65)
     at org.apache.catalina.startup.ContextConfig.applicationAnnotationsConfig(ContextConfig.java:403)
     at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:879)
     at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:374)
     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:5355)
     at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
     ... 6 more
 Caused by: java.lang.ClassNotFoundException: org.springframework.web.context.WebApplicationContext
     at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1720)
     at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1571)
     ... 20 more

网上百度大家都说是jar包缺少。但是检查spring所需要的jar包，都存在，如下图。

然后就看lib文件是不是有问题，果然有问题。

原来我的lib文件夹在WebContent下，将它放到WEB-INF目录下，再重新将jar包add to build path里，项目就能启动了。

现在将这个问题分享出来，希望能帮到其他的朋友。

可能我犯得这个错误很低级，别人不会犯这种错误吧。^_^