这里记录一下使用注解实现SSH拦截器，启动Tomcat时报Unable to load configuration. - [unknown location]错的一种解决方法。
下面是报错的详细信息：
Unable to load configuration. - [unknown location]
at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:428)
at org.apache.struts2.dispatcher.ng.InitOperations.initDispatcher(InitOperations.java:69)
at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:51)
at org.apache.catalina.core.ApplicationFilterConfig.initFilter(ApplicationFilterConfig.java:279)
at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:260)
at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:105)
at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4830)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5510)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1575)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1565)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Caused by: Unable to load configuration. - [unknown location]
at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:69)
at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:371)
at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:415)
... 14 more
Caused by: Unable to find interceptor class referenced by ref-name loginCheck - [unknown location]
at com.opensymphony.xwork2.config.providers.InterceptorBuilder.constructInterceptorReference(InterceptorBuilder.java:63)
at org.apache.struts2.convention.DefaultInterceptorMapBuilder.buildInterceptorList(DefaultInterceptorMapBuilder.java:99)
at org.apache.struts2.convention.DefaultInterceptorMapBuilder.build(DefaultInterceptorMapBuilder.java:90)
at org.apache.struts2.convention.DefaultInterceptorMapBuilder.build(DefaultInterceptorMapBuilder.java:74)
at org.apache.struts2.convention.PackageBasedActionConfigBuilder.createActionConfig(PackageBasedActionConfigBuilder.java:861)
at org.apache.struts2.convention.PackageBasedActionConfigBuilder.buildConfiguration(PackageBasedActionConfigBuilder.java:651)
at org.apache.struts2.convention.PackageBasedActionConfigBuilder.buildActionConfigs(PackageBasedActionConfigBuilder.java:336)
at org.apache.struts2.convention.ClasspathPackageProvider.loadPackages(ClasspathPackageProvider.java:53)
at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:215)
at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:66)
注意，我在信息里面highlight了一段信息，“loginCheck”是我使用注解时的名字，这里的错误并不是向网上其他人所报的jar包冲突，或者“file:/D:/apache-tomcat-6.0.29/webapps/DE/WEB-INF/classes/struts.xml:10:42”之类的错误，这里的错误明显指的是找不到相关信息，查证一下，发现是少了一个重要的注解，就是@ParentPackage("restrant")，这是声明拦截器所在的包的名字。先贴一下struts.xml配置文件出来，就明白了。
<struts>
<constant name="struts.i18n.encoding" value="utf-8"></constant>
<package name="restrant" namespace="/" extends="struts-default">
<!-- 配置拦截器AuthorityInterceptor -->
<interceptors>
<interceptor name="loginCheck" class="com.restrant.interceptor.AuthorityInterceptor" />
<interceptor-stack name="auctionStack">
<interceptor-ref name="defaultStack"/>
<interceptor-ref name="loginCheck"/>
</interceptor-stack>
</interceptors>
<default-interceptor-ref name="auctionStack"/>
</package>
</struts>配置文件里面的loginCheck拦截器是在名为“restrant”的package下面，所以在Action类里面如果要使用“loginCheck”拦截器的话，就是加上@ParentPackage("restrant")这句注解。