刚学习Struts，自己写了个简单程序，一启动tomcat就报错，但是我按着ctrl点击struts.xml中com.struts.action.LoginAction也能定位到LoginAction类，自己弄了半天，网上找了好久终于搞定了！
控制台报错：[color=#FF0000]Unable to load configuration. - action - file:/E:/tl/workspace/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps/struts2/WEB-INF/classes/struts.xml:11:82[/color]
at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:493)
at org.apache.struts2.dispatcher.ng.InitOperations.initDispatcher(InitOperations.java:74)
at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:57)
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:4775)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5452)
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.run(FutureTask.java:262)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:744)
Caused by: Unable to load configuration. - action - file:/E:/tl/workspace/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps/struts2/WEB-INF/classes/struts.xml:11:82
at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:70)
at org.apache.struts2.dispatcher.Dispatcher.getContainer(Dispatcher.java:967)
at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:435)
at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:479)
... 14 more
Caused by: Action class [com.struts.action.LoginAction] not found - action - file:/E:/tl/workspace/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps/struts2/WEB-INF/classes/struts.xml:11:82
at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.verifyAction(XmlConfigurationProvider.java:486)
at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.addAction(XmlConfigurationProvider.java:429)
at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.addPackage(XmlConfigurationProvider.java:556)
at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadPackages(XmlConfigurationProvider.java:295)
at org.apache.struts2.config.StrutsXmlConfigurationProvider.loadPackages(StrutsXmlConfigurationProvider.java:112)
at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:264)
at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:67)
... 17 more
网上查找有以下解决方法：
1.检查action的name值和url中的大小写是否相同。
2.检查action中的class的路径名和你写的类名的大小写。
3.参照struts确定是否引入不必要的jar包，引发冲突（这个不好查到）。
这些都尝试依然不行，又搞了好久最后才弄好。。。。
1.在项目webRoot下面新建一个classes文件夹，把struts.xml拖到下面，可以正常使用，启动不再报错（但这个不是根本原因），
2.清理缓存，clean项目，记住是在eclipse->project->clean这里面clean，以前我都是在server部署过的tomcat上面右键clean，导致clean不彻底，因此才导致这个错误的。。。。。。。。。。。。。。。。。。。。。。
转自：https://blog.csdn.net/tomcat_2014/article/details/46136133