慎用struts convension plugin

问题描述：

我在调试一个Struts2的application的时候，检查了所有的struts.xml中的action设置都正确，但是运行的时候返回结果如下：

HTTP Status 404 - No result defined for action com.×××.struts2.login.LoginAction and result error

type Status report

message No result defined for action com.ericsson.struts2.login.LoginAction and result error

description The requested resource (No result defined for action com.ericsson.struts2.login.LoginAction and result error) is not available.

如下为控制台抛出的异常：

Could not find action or result
No result defined for action com.ericsson.struts2.login.LoginAction and result error
at com.opensymphony.xwork2.DefaultActionInvocation.executeResult(DefaultActionInvocation.java:375)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:277)
at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:176)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:263)
at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)

                                      *********************************************************

        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:929)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:405)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:964)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:515)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:304)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

问题原因：

后经仔细分析发现，是因为多加载了struts2-convention-plugin-2.2.3.1.jar,删除该jar以后可以正常运行。貌似当加载这个convention plugin以后，会使用convention来配置Action，即使在struts.xml配置了action,也会被覆盖。