配置struts2报错，求大神帮忙

信息: Choosing bean (struts) for (org.apache.struts2.views.util.UrlHelper)
2013-3-22 10:42:22 com.opensymphony.xwork2.util.logging.commons.CommonsLogger error
严重: Dispatcher initialization failed
Unable to load configuration. - [unknown location]
	at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:70)
	at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:429)
	at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:473)
	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:275)
	at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:397)
	at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:108)
	at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:3800)
	at org.apache.catalina.core.StandardContext.start(StandardContext.java:4450)
	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:526)
	at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:987)
	at org.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:909)
	at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:495)
	at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1206)
	at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:314)
	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:722)
	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:516)
	at org.apache.catalina.core.StandardServer.start(StandardServer.java:710)
	at org.apache.catalina.startup.Catalina.start(Catalina.java:583)
	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:288)
	at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:413)
Caused by: Parent package is not defined: osgi-default - [unknown location]
	at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.buildPackageContext(XmlConfigurationProvider.java:662)
	at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.addPackage(XmlConfigurationProvider.java:510)
	at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadPackages(XmlConfigurationProvider.java:292)
	at org.apache.struts2.config.StrutsXmlConfigurationProvider.loadPackages(StrutsXmlConfigurationProvider.java:112)
	at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:250)