java.lang.NoClassDefFoundError: com/opensymphony/xwork2/config/FileManagerProvider

严重: Exception starting filter struts2
java.lang.NoClassDefFoundError: com/opensymphony/xwork2/config/FileManagerProvider
    at org.apache.struts2.dispatcher.Dispatcher.init_FileManager(Dispatcher.java:336)
    at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:463)
    at org.apache.struts2.dispatcher.ng.InitOperations.initDispatcher(InitOperations.java:74)
    at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:51)
    at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:295)
    at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:422)
    at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:115)
    at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:3838)
    at org.apache.catalina.core.StandardContext.start(StandardContext.java:4488)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:791)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:771)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:546)
    at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1041)
    at org.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:964)
    at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:502)
    at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1277)
    at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:321)
    at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1053)
    at org.apache.catalina.core.StandardHost.start(StandardHost.java:785)
    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)
    at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443)
    at org.apache.catalina.core.StandardService.start(StandardService.java:519)
    at org.apache.catalina.core.StandardServer.start(StandardServer.java:710)
    at org.apache.catalina.startup.Catalina.start(Catalina.java:581)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:289)
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414)
Caused by: java.lang.ClassNotFoundException: com.opensymphony.xwork2.config.FileManagerProvider
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1516)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1361)
    at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)
    ... 31 more
2013-6-15 8:47:49 org.apache.catalina.core.StandardContext start
严重: Error filterStart
2013-6-15 8:47:49 org.apache.catalina.core.StandardContext start
严重: Context [/Spring_1500_Registration_6] startup failed due to previous errors
2013-6-15 8:47:49 org.apache.catalina.core.ApplicationContext log
信息: Closing Spring root WebApplicationContext
2013-6-15 8:47:49 org.apache.catalina.loader.WebappClassLoader clearReferencesJdbc
严重: A web application registered the JBDC driver [com.mysql.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
2013-6-15 8:47:49 org.apache.catalina.loader.WebappClassLoader clearReferencesStopTimerThread
严重: A web application appears to have started a TimerThread named [Timer-0] via the java.util.Timer API but has failed to stop it. To prevent a memory leak, the timer (and hence the associated thread) has been forcibly cancelled.

log4j:ERROR LogMananger.repositorySelector was null likely due to error in class reloading, using NOPLoggerRepository.

原因是我将struts2-core-2.1.6.jar和struts2-spring-plugin-2.1.6.jar换成了2.3.8版本的。本来是想用新版本的替换掉的，想不到出了这个报错。