问题描述：
springweb项目，没有使用maven，是动态web工程（dynamic web project）,通过下图1的方式在本地开发，有时候电脑关机之后再开机、或者是关闭tomcat server再启动都有可能报出上面的错误：A child container failed during start。
图1
具体的报错信息是一大堆，我复制了下来：
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[/lzzcms]]
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:1119)
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$StartChild.call(ContainerBase.java:1571)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1561)
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[/lzzcms]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:162)
... 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:2499)
at java.lang.Class.getDeclaredFields(Class.java:1811)
at org.apache.catalina.util.Introspection.getDeclaredFields(Introspection.java:106)
at org.apache.catalina.startup.WebAnnotationSet.loadFieldsAnnotation(WebAnnotationSet.java:270)
at org.apache.catalina.startup.WebAnnotationSet.loadApplicationServletAnnotations(WebAnnotationSet.java:139)
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:891)
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:5522)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
... 6 more
Caused by: java.lang.ClassNotFoundException: org.springframework.web.context.WebApplicationContext
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1892)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1735)
... 20 more
三月 09, 2018 1:20:18 下午 org.apache.catalina.core.ContainerBase startInternal
严重: A child container failed during start
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost]]
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:1119)
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:300)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
at org.apache.catalina.core.StandardService.startInternal(StandardService.java:444)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:758)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
at org.apache.catalina.startup.Catalina.start(Catalina.java:693)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:294)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:428)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:162)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1571)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1561)
at java.util.concurrent.FutureTask.run(FutureTask.java:262)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1127)
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:819)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
... 6 more
三月 09, 2018 1:20:18 下午 org.apache.catalina.startup.Catalina start
严重: The required Server component failed to start so Tomcat is unable to start.
org.apache.catalina.LifecycleException: Failed to start component [StandardServer[8005]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:162)
at org.apache.catalina.startup.Catalina.start(Catalina.java:693)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:294)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:428)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardService[Catalina]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:162)
at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:758)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
... 7 more
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:162)
at org.apache.catalina.core.StandardService.startInternal(StandardService.java:444)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
... 9 more
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1127)
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:300)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
... 11 more
以往也经常出现这种启动报错的事情，肯定不是项目的原因这是没得说的，以前我记得排查了很长时间错误，网上也搜索了很多资料，但没有解决，就搁下了，没有再去找这个错误的原因，反正我再new server重新建一个服务器就又可以运行了（图2），也懒得去找为什么老的server莫名奇妙的会报这种错。
图2
近来又出现了上面的错误，这次终于找到解决办法了，因为这种通过new --->server的方式其实是把项目部署到了eclipse中，在项目启动的时候控制台上也会打印项目具体被部署到哪里了：
三月 09, 2018 1:20:14 下午 org.apache.catalina.startup.VersionLoggerListener log
信息: CATALINA_BASE: D:\workspace2\.metadata\.plugins\org.eclipse.wst.server.core\tmp0
解决方法：切换到上边的目录D:\workspace2\.metadata\.plugins\org.eclipse.wst.server.core\tmp0，我项目web-inf/lib下面有65个jar包，但是在D:\workspace2\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps\lzzcms\WEB-INF\lib目录下面只有64个，最后发现缺少了一个“spring-web-4.0.0.RELEASE.jar”，从项目的web-inf/lib下面把这个jar包拷贝到D:\workspace2\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps\lzzcms\WEB-INF\lib下面就能解决上面的问题了，拷贝完之后，启动成功。
其实上面报错信息也给你说了：
Caused by: java.lang.NoClassDefFoundError: org/springframework/web/context/WebApplicationContext
找不到WebApplicationContext这个类，而这个类就是在spring-web-4.0.0.RELEASE.jar这个jar包里面的。