求助，在启动struts2中启动tomcat时报错

java.lang.NullPointerException
at com.opensymphony.xwork2.util.FileManager$FileRevision.needsReloading(FileManager.java:209)
at com.opensymphony.xwork2.util.FileManager.fileNeedsReloading(FileManager.java:60)
at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.needsReload(XmlConfigurationProvider.java:325)
at org.apache.struts2.config.StrutsXmlConfigurationProvider.needsReload(StrutsXmlConfigurationProvider.java:168)
at com.opensymphony.xwork2.config.ConfigurationManager.conditionalReload(ConfigurationManager.java:220)
at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:61)
at org.apache.struts2.dispatcher.Dispatcher.getContainer(Dispatcher.java:774)
at org.apache.struts2.dispatcher.ng.InitOperations.initStaticContentLoader(InitOperations.java:77)
at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:49)
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:4001)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4651)
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:445)
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)
2013-9-9 18:43:10 org.apache.catalina.core.StandardContext start
严重: Error filterStart
2013-9-9 18:43:10 org.apache.catalina.core.StandardContext start
严重: Context [/Struts2_0300_Action] startup failed due to previous errors
2013-9-9 18:43:10 org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap
严重: The web application [/Struts2_0300_Action] created a ThreadLocal with key of type [null] (value [com.opensymphony.xwork2.inject.ContainerImpl$10@7421ff]) and a value of type [java.lang.Object[]] (value [[Ljava.lang.Object;@642c2e]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
2013-9-9 18:43:10 org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap
严重: The web application [/Struts2_0300_Action] created a ThreadLocal with key of type [null] (value [com.opensymphony.xwork2.inject.ContainerImpl$10@1052f49]) and a value of type [java.lang.Object[]] (value [[Ljava.lang.Object;@163956f]) but failed to remove it when the web application was stopped. This is very likely to creat --------------------编程问答-------------------- <?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">

<struts>
    <constant name="struts.devMode" value="true" />
    <package name="user" extends="struts-default" namespace="/user">
        <action name="userAdd" class="com.bjsxt.struts2.user.action.UserAction" method="add">
            <result>/user_add_success.jsp</result>
        </action>

        <action name="user" class="com.bjsxt.struts2.user.action.UserAction">
            <result>/user_add_success.jsp</result>
        </action>
    </package>
</struts>
这是struts的配置 --------------------编程问答-------------------- 刚刚查了下说是jar包问题，你都用了哪些jar???? --------------------编程问答-------------------- 只导了struts2的几个jar包？  还有web.xml里面配置正确了咩？

--------------------编程问答-------------------- 你确定不少包？ --------------------编程问答-------------------- 我觉得是包问题，找包吧！ --------------------编程问答-------------------- web.xml里面配置了StrutsPrepareAndExcuteFilter没有，如果配置了的话，就是应该是导入的包有问题 --------------------编程问答-------------------- 你这是空指针异常，也就是说你定义的变量没使用，或者你使用了没定义的变量，或者是数据库列数与jsp页面不一致。你仔细检查一下

补充：Java ,  Java EE