Struts2 访问不存在的Action报Unable to instantiate Action,该如何处理

Struts2 访问不存在的Action报Unable to instantiate Action
请问为什么struts2在访问不存在的Action,如：http://localhost:8080/Testweb/abc,
Testweb是我的项目名，abc是随便乱写的，然后报：

Unable to instantiate Action, com.shutao.test.action.abcAction,  defined for 'abc' in namespace '/'com.shutao.test.action.abcAction
	com.opensymphony.xwork2.DefaultActionInvocation.createAction(DefaultActionInvocation.java:307)
	com.opensymphony.xwork2.DefaultActionInvocation.init(DefaultActionInvocation.java:388)
	com.opensymphony.xwork2.DefaultActionProxy.prepare(DefaultActionProxy.java:187)
	org.apache.struts2.impl.StrutsActionProxy.prepare(StrutsActionProxy.java:61)
	org.apache.struts2.impl.StrutsActionProxyFactory.createActionProxy(StrutsActionProxyFactory.java:39)
	com.opensymphony.xwork2.DefaultActionProxyFactory.createActionProxy(DefaultActionProxyFactory.java:47)
	org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:478)
	org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:395)
	org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
	org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)

root cause

java.lang.ClassNotFoundException: com.shutao.test.action.abcAction
	org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1387)
	org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1233)
	com.opensymphony.xwork2.util.ClassLoaderUtil.loadClass(ClassLoaderUtil.java:146)
	com.opensymphony.xwork2.ObjectFactory.getClassInstance(ObjectFactory.java:96)
	com.opensymphony.xwork2.spring.SpringObjectFactory.getClassInstance(SpringObjectFactory.java:212)
	com.opensymphony.xwork2.spring.SpringObjectFactory.buildBean(SpringObjectFactory.java:132)
	com.opensymphony.xwork2.ObjectFactory.buildBean(ObjectFactory.java:139)
	com.opensymphony.xwork2.ObjectFactory.buildAction(ObjectFactory.java:109)
	com.opensymphony.xwork2.DefaultActionInvocation.createAction(DefaultActionInvocation.java:288)
	com.opensymphony.xwork2.DefaultActionInvocation.init(DefaultActionInvocation.java:388)
	com.opensymphony.xwork2.DefaultActionProxy.prepare(DefaultActionProxy.java:187)
	org.apache.struts2.impl.StrutsActionProxy.prepare(StrutsActionProxy.java:61)
	org.apache.struts2.impl.StrutsActionProxyFactory.createActionProxy(StrutsActionProxyFactory.java:39)
	com.opensymphony.xwork2.DefaultActionProxyFactory.createActionProxy(DefaultActionProxyFactory.java:47)
	org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:478)
	org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:395)
	org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
	org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)

请问为什么不是报404,是哪里出问题。
麻烦帮下新手，谢谢！
------解决方案--------------------
改成<action name="*-*Action" class="com.shutao.test.action.{1}Action" method="{2}">试试