比较熟悉的是2.3版本，前些日子听说升级了2.5，马上试了一下
明显的区别是把xwork和struts-core两个jar合在了一起，在其他方面据说提升了安全性能（Struts频频被曝出的漏洞表示不服。。）

我把2.5的corejar引入到项目中，其他的没变，Tomcat提示org.apache.catalina.LifecycleException并无法启动。

jarfiles：

报错信息：

SEVERE: A child container failed during start java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/Struts2Refactory]] at java.util.concurrent.FutureTask.report(Unknown Source) at java.util.concurrent.FutureTask.get(Unknown Source) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:915) at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:871) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1407) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1397) at java.util.concurrent.FutureTask.run(Unknown Source) at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at java.lang.Thread.run(Unknown Source) Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/Struts2Refactory]] at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:153) ... 6 more Caused by: java.lang.NoClassDefFoundError: Lorg/apache/logging/log4j/Logger; at java.lang.Class.getDeclaredFields0(Native Method) at java.lang.Class.privateGetDeclaredFields(Unknown Source) at java.lang.Class.getDeclaredFields(Unknown Source) at org.apache.catalina.util.Introspection.getDeclaredFields(Introspection.java:106) at org.apache.catalina.startup.WebAnnotationSet.loadFieldsAnnotation(WebAnnotationSet.java:256) at org.apache.catalina.startup.WebAnnotationSet.loadApplicationFilterAnnotations(WebAnnotationSet.java:105) at org.apache.catalina.startup.WebAnnotationSet.loadApplicationAnnotations(WebAnnotationSet.java:64) at org.apache.catalina.startup.ContextConfig.applicationAnnotationsConfig(ContextConfig.java:335) at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:782) at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:306) at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:95) at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5202) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147) ... 6 more Caused by: java.lang.ClassNotFoundException: org.apache.logging.log4j.Logger at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1332) at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1166) ... 20 more Jul 14, 2016 2:34:08 PM org.apache.catalina.core.ContainerBase startInternal SEVERE: 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(Unknown Source) at java.util.concurrent.FutureTask.get(Unknown Source) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:915) at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147) at org.apache.catalina.core.StandardService.startInternal(StandardService.java:441) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147) at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:787) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147) at org.apache.catalina.startup.Catalina.start(Catalina.java:629) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) 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:153) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1407) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1397) at java.util.concurrent.FutureTask.run(Unknown Source) at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at java.lang.Thread.run(Unknown Source) Caused by: org.apache.catalina.LifecycleException: A child container failed during start at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:923) at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:871) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147) ... 6 more Jul 14, 2016 2:34:08 PM org.apache.catalina.startup.Catalina start SEVERE: 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:153) at org.apache.catalina.startup.Catalina.start(Catalina.java:629) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) 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 [StandardService[Catalina]] at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:153) at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:787) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147) ... 7 more Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina]] at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:153) at org.apache.catalina.core.StandardService.startInternal(StandardService.java:441) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147) ... 9 more Caused by: org.apache.catalina.LifecycleException: A child container failed during start at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:923) at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147) ... 11 more Jul 14, 2016 2:34:08 PM org.apache.coyote.AbstractProtocol pause INFO: Pausing ProtocolHandler ["http-nio-8088"] Jul 14, 2016 2:34:08 PM org.apache.coyote.AbstractProtocol pause INFO: Pausing ProtocolHandler ["ajp-nio-8009"] Jul 14, 2016 2:34:08 PM org.apache.catalina.core.StandardService stopInternal INFO: Stopping service Catalina Jul 14, 2016 2:34:08 PM org.apache.coyote.AbstractProtocol destroy INFO: Destroying ProtocolHandler ["http-nio-8088"] Jul 14, 2016 2:34:08 PM org.apache.coyote.AbstractProtocol destroy SEVERE: Failed to destroy end point associated with ProtocolHandler ["http-nio-8088"] java.lang.NullPointerException at org.apache.tomcat.util.net.NioEndpoint.releaseCaches(NioEndpoint.java:316) at org.apache.tomcat.util.net.NioEndpoint.unbind(NioEndpoint.java:492) at org.apache.tomcat.util.net.AbstractEndpoint.destroy(AbstractEndpoint.java:821) at org.apache.coyote.AbstractProtocol.destroy(AbstractProtocol.java:534) at org.apache.catalina.connector.Connector.destroyInternal(Connector.java:1023) at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:297) at org.apache.catalina.core.StandardService.destroyInternal(StandardService.java:589) at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:297) at org.apache.catalina.core.StandardServer.destroyInternal(StandardServer.java:877) at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:297) at org.apache.catalina.startup.Catalina.start(Catalina.java:633) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:351) at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:485) Jul 14, 2016 2:34:08 PM org.apache.coyote.AbstractProtocol destroy INFO: Destroying ProtocolHandler ["ajp-nio-8009"] Jul 14, 2016 2:34:08 PM org.apache.coyote.AbstractProtocol destroy SEVERE: Failed to destroy end point associated with ProtocolHandler ["ajp-nio-8009"] java.lang.NullPointerException at org.apache.tomcat.util.net.NioEndpoint.releaseCaches(NioEndpoint.java:316) at org.apache.tomcat.util.net.NioEndpoint.unbind(NioEndpoint.java:492) at org.apache.tomcat.util.net.AbstractEndpoint.destroy(AbstractEndpoint.java:821) at org.apache.coyote.AbstractProtocol.destroy(AbstractProtocol.java:534) at org.apache.catalina.connector.Connector.destroyInternal(Connector.java:1023) at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:297) at org.apache.catalina.core.StandardService.destroyInternal(StandardService.java:589) at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:297) at org.apache.catalina.core.StandardServer.destroyInternal(StandardServer.java:877) at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:297) at org.apache.catalina.startup.Catalina.start(Catalina.java:633) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:351) at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:485)