eclipse 在tomcat8运行出现ContainerBase.addChild: start: org.apache.catalina.LifecycleException: Failed t

运行前几次还是好好的，突然出现这个问题

严重: ContainerBase.addChild: start:
org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/ShowOrder]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:632)
at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1229)
at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1875)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
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: java.lang.NoClassDefFoundError: javax/faces/webapp/FacesServlet
at com.sun.faces.config.FacesInitializer.<clinit>(FacesInitializer.java:103)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:270)
at org.apache.catalina.startup.WebappServiceLoader.loadServices(WebappServiceLoader.java:187)
at org.apache.catalina.startup.WebappServiceLoader.load(WebappServiceLoader.java:152)
at org.apache.catalina.startup.ContextConfig.processServletContainerInitializers(ContextConfig.java:1543)
at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1265)
at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:873)
at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:371)
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)
... 10 more
Caused by: java.lang.ClassNotFoundException: javax.faces.webapp.FacesServlet
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1720)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1571)
... 23 more
六月 19, 2014 11:53:01 上午 org.apache.catalina.startup.HostConfig deployDirectory
严重: Error deploying web application directory E:\developSoftware\apache-tomcat-7.0.53\webapps\ShowOrder
java.lang.IllegalStateException: ContainerBase.addChild: start: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/ShowOrder]]
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:904)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:632)
at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1229)
at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1875)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
at java.util.concurrent.FutureTask.run(FutureTask.java:262)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
六月 19, 2014 11:53:01 上午 org.apache.catalina.startup.HostConfig deployDirectory
信息: Deploying web application directory E:\developSoftware\apache-tomcat-7.0.53\webapps\test
六月 19, 2014 11:53:01 上午 org.apache.coyote.AbstractProtocol start
信息: Starting ProtocolHandler ["http-apr-8080"]
六月 19, 2014 11:53:01 上午 org.apache.coyote.AbstractProtocol start
信息: Starting ProtocolHandler ["ajp-apr-8009"]
六月 19, 2014 11:53:01 上午 org.apache.catalina.startup.Catalina start
信息: Server startup in 11767 ms

在网上面看他们的解决办法根本没有用，最后把这个项目换了一个工作空间后，发现可以了，又回到原来工作空间，发现还是不行，然后又把tomcat8换成tomcat7，又可以了，所以解决办法就是，把现在的tomcat删掉，重新添加tomcat，后解决问题。