以前没出现过，百度了，依旧没解决。请问这是怎么回事，该怎么解决？谢谢！（tomcat8）
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/web]]
at java.util.concurrent.FutureTask.report(FutureTask.java:122)
at java.util.concurrent.FutureTask.get(FutureTask.java:192)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/web]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
... 6 more
Caused by: org.apache.catalina.LifecycleException: Failed to start component [org.apache.catalina.webresources.StandardRoot@26fd33fc]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
at org.apache.catalina.core.StandardContext.resourcesStart(StandardContext.java:4854)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:4984)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
... 6 more
Caused by: java.lang.IllegalArgumentException: The main resource set specified [E:\web] is not valid
at org.apache.catalina.webresources.StandardRoot.createMainResourceSet(StandardRoot.java:723)
at org.apache.catalina.webresources.StandardRoot.startInternal(StandardRoot.java:684)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
... 9 more
23-Jan-2016 12:59:05.562 SEVERE [Catalina-startStop-1] org.apache.catalina.core.ContainerBase.startInternal A child container failed during start
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/test]]
at java.util.concurrent.FutureTask.report(FutureTask.java:122)
at java.util.concurrent.FutureTask.get(FutureTask.java:192)
at java.lang.Thread.run(Thread.java:745)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/test]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
... 6 more
Caused by: org.apache.catalina.LifecycleException: Failed to start component [org.apache.catalina.webresources.StandardRoot@1b56755a]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
at org.apache.catalina.core.StandardContext.resourcesStart(StandardContext.java:4854)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:4984)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
... 6 more
Caused by: java.lang.IllegalArgumentException: The main resource set specified [E:\test] is not valid
at org.apache.catalina.webresources.StandardRoot.createMainResourceSet(StandardRoot.java:723)
at org.apache.catalina.webresources.StandardRoot.startInternal(StandardRoot.java:684)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
... 9 more
23-Jan-2016 12:59:05.594 SEVERE [main] org.apache.catalina.core.ContainerBase.startInternal 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:192)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:916)
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:351)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:485)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1408)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1398)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
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:924)
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:871)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
... 6 more
23-Jan-2016 12:59:05.813 SEVERE [main] org.apache.catalina.startup.Catalina.start 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:
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:485)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardService[Catalina]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:769)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
... 7 more
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
at org.apache.catalina.core.StandardService.startInternal(StandardService.java:439)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
... 9 more
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:924)
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
... 11 more
23-Jan-2016 12:59:05.963 INFO [main] org.apache.coyote.AbstractProtocol.pause Pausing ProtocolHandler ["http-nio-8080"]
23-Jan-2016 12:59:05.979 INFO [main] org.apache.coyote.AbstractProtocol.pause Pausing ProtocolHandler ["ajp-nio-8009"]
23-Jan-2016 12:59:05.994 INFO [main] org.apache.catalina.core.StandardService.stopInternal Stopping service Catalina
23-Jan-2016 12:59:06.010 INFO [main] org.apache.coyote.AbstractProtocol.destroy Destroying ProtocolHandler ["http-nio-8080"]
23-Jan-2016 12:59:06.010 SEVERE [main] org.apache.coyote.AbstractProtocol.destroy Failed to destroy end point associated with ProtocolHandler ["http-nio-8080"]
java.lang.NullPointerException
at org.apache.tomcat.util.net.NioEndpoint.releaseCaches(NioEndpoint.java:305)
at org.apache.tomcat.util.net.NioEndpoint.unbind(NioEndpoint.java:481)
at org.apache.tomcat.util.net.AbstractEndpoint.destroy(AbstractEndpoint.java:823)
Destroying ProtocolHandler ["ajp-nio-8009"]
23-Jan-2016 12:59:06.135 SEVERE [main] org.apache.coyote.AbstractProtocol.destroy Failed to destroy end point associated with ProtocolHandler ["ajp-nio-8009"]
java.lang.NullPointerException
at org.apache.tomcat.util.net.NioEndpoint.releaseCaches(NioEndpoint.java:305)
at org.apache.tomcat.util.net.NioEndpoint.unbind(NioEndpoint.java:481)
at org.apache.tomcat.util.net.AbstractEndpoint.destroy(AbstractEndpoint.java:823)
at org.apache.coyote.AbstractProtocol.destroy(AbstractProtocol.java:532)
at org.apache.catalina.connector.Connector.destroyInternal(Connector.java:1023)
at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:305)
at org.apache.catalina.core.StandardService.destroyInternal(StandardService.java:588)
at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:305)
at org.apache.catalina.core.StandardServer.destroyInternal(StandardServer.java:859)
at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:305)
at org.apache.catalina.startup.Catalina.start(Catalina.java:629)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:351)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:485)
