Exception starting filter struts2 java.lang.NullPointerException 问题解决

一个Struts2小程序，在改DevModel为true后调试出了问题,

<constant name="struts.devMode" value="true" />
	 
	<package name="default" namespace="/" extends="struts-default">
 
        <action name="hell">
            <result>
                /Hello.jsp
            </result>
        </action>
    </package>

严重: Exception starting filter struts2

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: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)

2013-1-30 21:40:14 org.apache.catalina.core.StandardContext start

在DevModel为false的时候程序正常，当这个改动可能对以后的程序开发比较麻烦。。网上查了一下，是struts2的一个bug，简单的方法就是在Tomcat安装目录中不要出现空格，经测试，方法正确，问题解决了。(本人使用:struts-2.3.8-all和tomcat-6.0.26.exe)