There is no Action mapped for namespace [/] and action name [] associated with context path [/ch_05_ActionAnnotation].

There is no Action mapped for namespace [/] and action name [] associated with context path [/ch_05_ActionAnnotation]. - [unknown location]
 at com.opensymphony.xwork2.DefaultActionProxy.prepare(DefaultActionProxy.java:185)
 at org.apache.struts2.impl.StrutsActionProxy.prepare(StrutsActionProxy.java:63)
 at org.apache.struts2.impl.StrutsActionProxyFactory.createActionProxy(StrutsActionProxyFactory.java:37)
 at com.opensymphony.xwork2.DefaultActionProxyFactory.createActionProxy(DefaultActionProxyFactory.java:58)
 at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:554)
 at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:81)
 at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:99)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
 at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
 at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
 at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
 at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
 at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
 at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
 at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
 at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1002)
 at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:585)
 at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
 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)

web.xml里面出现的问题，以上的问题是，web.xml配置的初始跳转页不存在，即

<welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>

该项目不存在以上配置的jsp或HTML文件