使用struts1-plugin调用action时的实例化异常

Question

我们使用struts1-plugin来封装我们的操作，将旧的struts1应用程序迁移到struts2。
这对于某些操作非常有效，但其他操作会抛出如下所示的错误:

java.lang.InstantiationException 
sun.reflect.InstantiationExceptionConstructorAccessorImpl.newInstance(InstantiationExceptionConstructorAccessorImpl.java:48)
java.lang.reflect.Constructor.newInstance(Constructor.java:526)
java.lang.Class.newInstance(Class.java:374)
com.opensymphony.xwork2.ObjectFactory.buildBean(ObjectFactory.java:158)
com.opensymphony.xwork2.ObjectFactory.buildBean(ObjectFactory.java:189)
com.opensymphony.xwork2.ObjectFactory.buildBean(ObjectFactory.java:178)
com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.resolveModel(ScopedModelDrivenInterceptor.java:106)
com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:136)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:191)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54)
org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:564)
org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:81)
org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:99)
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
de.dak.intranet.webtier.extranet.StartPageFilter.doFilter(StartPageFilter.java:74)
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
de.dak.intranet.webtier.auth.LoginFilter.doFilter(LoginFilter.java:288)
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:504)
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:421)
org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1074)
org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:314)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
java.lang.Thread.run(Thread.java:745)

这个动作的配置非常简单:

<package name="extranet" extends="struts1-default" namespace="/extranet">
  <action name="acceptConditions" class="org.apache.struts2.s1.Struts1Action>
    <param name="className">de.intranet.webtier.extranet.AcceptConditionsAction</param>
    <interceptor-ref name="struts1Stack"/>
    <result name="success">/servlet/index.jsp</result>
  </action>
</package>

我试图在行动中删除拦截器，但这并没有改变任何东西。操作类看起来像这样(省略了实际的逻辑):

public class AcceptConditionsAction extends Action {
  public ActionForward execute(ActionMapping mapping, 
                               ActionForm form, 
                               HttpServletRequest request, 
                               HttpServletResponse response) 
        throws Exception {
    return mapping.findForward("success");
  }
}

我们的jsp模板中的链接使用s:action标签正确构建，并且当单击该链接时，同一站点上的另一个操作可以完美地工作。然而，这个动作产生上面显示的堆栈跟踪，我不知道它是从哪里来的，也不知道如何修复它。动作内部的断点永远不会到达，因此错误必须在实例化动作本身时发生。

我希望有人能帮我弄清楚发生了什么事。

编辑:澄清工作动作:

<package name="extranet" extends="struts1-default" namespace="/extranet">
  <interceptors>
    <interceptor name="pwdForm" class="com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor>
      <param name="className">de.intranet.webtier.extranet.PasswordForm</param>
      <param name="name">pwdForm</param>
    </interceptor>
  </interceptors>
  <action name="editPassword" class="org.apache.struts2.s1.Struts1Action">
    <param name="className">de.intranet.webtier.extranet.EditPasswordAction</param>
    <interceptor-ref name="pwdForm"/>
    <interceptor-ref name="struts1Stack"/>
    <result name="changePassword">/extranet/changePassword.jsp</result>
  </action>
</package>

Java实现看起来像AcceptConditionsAction。只有execute-method被覆盖，没有定义构造函数。

Answer 1

Aleksandr向我指出了答案:由struts1-plugin(称为struts1Stack)提供的拦截器堆栈创建了几个需要表单的拦截器(即scopedModelDriven, modelDriven和其他一些)。如果您不使用整个堆栈，只添加动作所需的拦截器，则不再需要定义FormBean。

Answer 2

删除interceptor-ref "strutsStack"，添加"staticParams"即可。如下所示

<package name="extranet" extends="struts1-default" namespace="/extranet">
  <action name="acceptConditions" class="org.apache.struts2.s1.Struts1Action>
    <param name="className">de.intranet.webtier.extranet.AcceptConditionsAction</param>
    <!--interceptor-ref name="struts1Stack"/-->
    <interceptor-ref name="staticParams"/>
    <result name="success">/servlet/index.jsp</result>
  </action>
</package>