spring mvc 返回页面数据

package com.stone.controller;

import java.util.Map;

import javax.servlet.http.HttpServletRequest;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

/**
 * user/list.do user/add.do
 */
@Controller
@RequestMapping("/user")
public class UserController {

    @RequestMapping("/add1.do")
    public String add(HttpServletRequest request) {
        String userNum = request.getParameter("userNum");
        String passWord = request.getParameter("passWord");
        String x = "userNum:" + userNum + "   passWord:" + passWord;
        System.out.println(x);
        request.setAttribute("user", x);
        return "user_add1";
    }

    @RequestMapping("/add2.do")
    public ModelAndView add2() {

        ModelAndView mav = new ModelAndView("user_add1");
        mav.addObject("userId", 1001);
        mav.addObject("userName", "张三");
        return mav;
    }

    @RequestMapping("/add3.do")
    public String add3(Model model) {
        model.addAttribute("personId", 9527);
        model.addAttribute("personName", "唐伯虎");
        return "user_add1";
    }

    @RequestMapping("/add4.do")
    public String add4(Map<String, Object> map) {
        // 这样是获取不到的；
        System.out.println("-----" + map.get("personId"));
        map.put("personId", 9528);
        map.put("personName", "唐伯虎1");
        return "user_add1";
    }

    
}