struts 中的DispatchAction使用时的问题!!jsp!!

Question

我用SSH的struts,写了个Action,继承DispatchAction,
public ActionForward list(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response) {
List list=usersManager.getUsers(new Users());
request.setAttribute("users", list);
return mapping.findForward("showusers");
}

public ActionForward delete(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response) {
String id=request.getParameter("userid");
Integer userid=new Integer(Integer.parseInt(id));
usersManager.deleteUsers(userid);
return list(mapping,form,request,response);
}

public ActionForward update(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response) {
String id=request.getParameter("userid");
Integer userid=new Integer(Integer.parseInt(id));
Users user=usersManager.getUsers(userid);
request.setAttribute("user",user);
return mapping.findForward("updateuser");
}用JSP调用时:  <html:link action="users?method=list">返回</html:link>   成功这样调用时: <html:link action="users?method=update
          &userid=${user.userid}">修改</html:link>          <html:link action="users?method=delete
          &userid=${user.userid}">删除</html:link>                    都失败

Answer 1

如果这样的话应该是没有拿到那个userid。没猜错的话应该是数据转换异常

Answer 2

它报错:javax.servlet.ServletException: java.lang.NoSuchMethodException: Action[/users] does not contain specified method (check logs)
当我把它变成:<html:link action="users?method=delete">删除</html:link>时
就报:javax.servlet.ServletException: java.lang.NumberFormatException: null

Answer 3

配置文件中<action
      attribute=""
      input=""
      name=""
      parameter=""
      path=""
      scope="">
      <forward name="" path="" />     
    </action>parameter="" 写了吗！！！