There is no Action mapped for namespace / and action name . - [unknown location]

There is no Action mapped for namespace / and action name . - [unknown location] at com.opensymphony.xwork2.DefaultActionProxy.prepare(DefaultActionProxy.java:177) at org.apache.struts2.impl.StrutsActionProxy.prepare(StrutsActionProxy.java:61) at org.apache.struts2.impl.StrutsActionProxyFactory.createActionProxy(StrutsActionProxyFactory.java:39) at com.opensymphony.xwork2.DefaultActionProxyFactory.createActionProxy(DefaultActionProxyFactory.java:47) at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:458) at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77) at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:76) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:845) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583) at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447) at java.lang.Thread.run(Thread.java:619)

解决方法：

把struts.xml中package的namespace=“/”去掉。

把你在struts.xml中的namespace="/"换成namespace="/tt"的话
那么在你的jsp页面上
<s:form action="/tt/login"> 或者写成
<s:form action="/tt/login" namespace="/tt">