哪里错了吗？无法实现add的result

package com.zsq.action;

import javax.servlet.http.HttpServletRequest;

import com.opensymphony.xwork2.ActionSupport;

public class HelloWorldAction extends ActionSupport {
	private HttpServletRequest request;

	public String add() {
		request.setAttribute("path", "update");
		return "add";
	}

	public String update() {
		return "update";
	}

	@Override
	public String execute() throws Exception {
		// TODO Auto-generated method stub
		System.out.println("执行action");
		return SUCCESS;
	}
}

<?xml version="1.0" encoding="UTF-8"?>
   <!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.1//EN" "http://struts.apache.org/dtds/struts-2.1.dtd">
<struts>
   <package name="defult" namespace="/"  extends="struts-default">
   
   <default-action-ref name="index"></default-action-ref>
   <action name="index">
       <result>/error.jsp</result>
   </action>
   
   <action name="*_*" method="{2}" class="com.zsq.action.{1}Action">
        <result>/result.jsp</result>
        <result name="add">
        
        <param name="location">/${#request.path}.jsp</param>
        
        </result>
        <result name="update">/{2}.jsp</result>
        <result name="error">/error.jsp</result>
   </action>
   
      <action name="LoginAction" method="login" class="com.zsq.action.LoginAction">
        <result>/success.jsp</result>
        <result name="input">/login.jsp</result>
   </action>

   </package>
   </struts>