java的反射问题,谁帮帮小弟啊,getMethod和invoke怎么用哦

我的基类
public abstract class ActionBase extends Action {    public abstract Object init(ActionConfig actionConfig) throws Exception;    public ActionForward execute(ActionMapping mapping,ActionForm form,HttpServletRequest request,HttpServletResponse response) throws IOException,ServletException, SecurityException,
            NoSuchMethodException, InvocationTargetException,Exception,
            IllegalArgumentException, IllegalAccessException {
        ActionForward actionForward = null;        String method = request.getParameter("method");
        System.out.println(method);
        String message = "";
        if(method == null){           method = "";
        }
        //创建一个ActionConfig方法用来封装配置信息
        ActionConfig actionCfg = new ActionConfig(mapping,form,request,response);
        //得到当前类的对象        Class c = this.getClass();
   System.out.println(c.getName());
        //通过传过来的方法名(method)在它的子类中查找这个方法
        Method methodName = c.getMethod(method,new Class[] {ActionConfig.class});
   System.out.println(methodName.getName());
        if(methodName == null){
            message = "没有找到这个方法名！";
            actionCfg.getRequest().setAttribute("message",message);
            actionCfg.getMapping().findForward("");
        }
        Object[] arg = {actionCfg};
        //转入到方法名为methodName的方法中执行操作
        actionForward = (ActionForward)methodName.invoke(this,arg);        return actionForward;
    }    //public abstract ActionForward method(ActionConfig actionCfg);
}封装ActionConfig信息的类:
 public class ActionConfig {
      private ActionMapping mapping;
      private ActionForm form;
      private HttpServletRequest request;
      private HttpServletResponse response;      public ActionConfig(ActionMapping mapping,ActionForm form,HttpServletRequest request,HttpServletResponse response){
          this.mapping = mapping;
          this.form = form;
          this.request = request;
          this.response = response;
      }      public ActionMapping getMapping(){
          return mapping;
      }      public ActionForm getForm(){
          return form;
      }      public HttpServletRequest getRequest(){
          return request;
      }      public HttpServletResponse getResponse(){
          return response;
      }
  }在的Action类:
public  class LoginAction extends ActionBase  {
    com.book.util.Hibernate hbm=new com.book.util.Hibernate();
    /** public ActionForward execute(ActionMapping mapping,
                                     ActionForm actionForm,
                                     HttpServletRequest request,
                                     HttpServletResponse response)throws HibernateException,IOException {   
    public  ActionForward performLogin(ActionConfig cfg) throws
            HibernateException {
        String target="suss";
        System.out.println(target);
        ActionErrors errors = new ActionErrors();
        LoginForm loginForm = (LoginForm)cfg.getForm();
        String username=loginForm.getUsername();
        String psw=loginForm.getPsw();
  if(!hbm.isLogin(username,psw)){
            target="fail";
            errors.add("loginError",new ActionError("error.logerror"));
             saveErrors(cfg.getRequest(),errors);
        }
        else{
            HttpSession session = cfg.getRequest().getSession();
            session.setAttribute("username", username);        }
   return cfg.getMapping().findForward(target);    }当输入...?method=performLogin   老是报错
javax.servlet.ServletException: struts.Action.RoleAction.performSyslist(struts.ActionConfig)
org.apache.struts.action.RequestProcessor.processException(RequestProcessor.java:516)
org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:423)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:226)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1164)
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:415)
javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
root cause java.lang.NoSuchMethodException: struts.Action.RoleAction.performSyslist(struts.ActionConfig)
java.lang.Class.getMethod(Class.java:1581)
struts.ActionBase.execute(ActionBase.java:39)
org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:421)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:226)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1164)
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:415)
javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)