启动tomcat部署项目时 ContainerBase.addChild: start:

严重: ContainerBase.addChild: start:
org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/ServeletExercise]]
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:652)
at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1263)
at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1948)
at java.util.concurrent.Executors$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$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:744)
Caused by: java.lang.IllegalArgumentException: Servlet mapping specifies an unknown servlet name IdentityServelet
at org.apache.catalina.core.StandardContext.addServletMapping(StandardContext.java:3320)
at org.apache.catalina.core.StandardContext.addServletMapping(StandardContext.java:3299)
at org.apache.catalina.deploy.WebXml.configureContext(WebXml.java:1438)
at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1357)
at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:889)
at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:386)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)
at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5416)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
... 10 more
六月 08, 2015 10:52:10 上午 org.apache.catalina.startup.HostConfig deployDirectory
严重: Error deploying web application directory D:\ProgramSoft\apache-tomcat-7.0.62\webapps\ServeletExercise
java.lang.IllegalStateException: ContainerBase.addChild: start: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/ServeletExercise]]
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:904)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:652)
at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1263)
at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1948)
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:744)
六月 08, 2015 10:52:10 上午 org.apache.catalina.startup.HostConfig deployDirectory
信息: Deployment of web application directory D:\ProgramSoft\apache-tomcat-7.0.62\webapps\ServeletExercise has finished in 233 ms
六月 08, 2015 10:52:10 上午 org.apache.coyote.AbstractProtocol start
信息: Starting ProtocolHandler ["http-apr-8080"]
六月 08, 2015 10:52:10 上午 org.apache.coyote.AbstractProtocol start
信息: Starting ProtocolHandler ["ajp-apr-8009"]
六月 08, 2015 10:52:10 上午 org.apache.catalina.startup.Catalina start
信息: Server startup in 3533 ms