在启动tomcat时报了一个异常，一直导致项目运行不起来
应该有很多初学者都会有这个问题出现，下面是我记录下自己从发现问题到排查到解决问题的过程。
SEVERE: ContainerBase.addChild: start:
org.apache.catalina.LifecycleException:Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/transPlatformWeb]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:162)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:1017)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:993)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:652)
at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1296)
at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:2039)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
at java.util.concurrent.FutureTask.run(FutureTask.java:166)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:722)
Caused by: java.lang.NoClassDefFoundError: IOException
at java.lang.Class.getDeclaredMethods0(Native Method)
at java.lang.Class.privateGetDeclaredMethods(Class.java:2451)
at java.lang.Class.getDeclaredMethods(Class.java:1810)
at org.apache.catalina.util.Introspection.getDeclaredMethods(Introspection.java:127)
at org.apache.catalina.startup.WebAnnotationSet.loadMethodsAnnotation(WebAnnotationSet.java:286)
at org.apache.catalina.startup.WebAnnotationSet.loadApplicationServletAnnotations(WebAnnotationSet.java:139)
at org.apache.catalina.startup.WebAnnotationSet.loadApplicationAnnotations(WebAnnotationSet.java:70)
at org.apache.catalina.startup.ContextConfig.applicationAnnotationsConfig(ContextConfig.java:417)
at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:881)
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:5566)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
... 11 more
Caused by: java.lang.ClassNotFoundException: IOException
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1928)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1771)
... 25 more
八月 03, 2018 11:22:20 上午 org.apache.catalina.startup.HostConfig deployDirectory
SEVERE: Error deploying web application directory D:\公司开发软件\apache-tomcat-7.0.88\webapps\transPlatformWeb
java.lang.IllegalStateException: ContainerBase.addChild: start: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/transPlatformWeb]]
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:1021)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:993)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:652)
at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1296)
at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:2039)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
at java.util.concurrent.FutureTask.run(FutureTask.java:166)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:722)
其中找不到类定义，就从XML文件开始排查，发现根本没有问题。
后面再从拦截器中查找，判断是否被拦截了资源，发现也没问题。
最后发现这个异常，其实是项目运行环境为1.7
但是Project Facets中java编译版本是1.6 导致部分映射文件无法编译
修改以后，完美解决
