Struts2 扫描包中的 ParentPackage 老是提示 parent package 里面的值是unknown location，具体错误信息如下：
1:10:14.318 [localhost-startStop-1] INFO o.s.w.c.s.XmlWebApplicationContext - Closing org.springframework.web.context.support.XmlWebApplicationContext@1a8e045: display name [Root WebApplicationContext]; startup date [Thu May 16 11:10:12 CST 2013]; root of context hierarchy
11:10:14.318 [localhost-startStop-1] INFO o.s.b.f.s.DefaultListableBeanFactory - Destroying singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@13df2a2: defining beans []; root of factory hierarchy
五月 16, 2013 11:10:14 上午 org.apache.catalina.core.StandardContext filterStart
SEVERE: Exception starting filter struts2
Unable to load configuration. - [unknown location]
at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:485)
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.initFilter(ApplicationFilterConfig.java:281)
at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:262)
at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:107)
at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4656)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5309)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: 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)