Spring MVC returns page data

Handler

 PackageCom.stone.controller;ImportJava.util.Map;Importjavax.servlet.http.HttpServletRequest;ImportOrg.springframework.stereotype.Controller;ImportOrg.springframework.ui.Model;Importorg.springframework.web.bind.annotation.RequestMapping;ImportOrg.springframework.web.servlet.ModelAndView;/*** user/list.do user/add.do*/@Controller @requestmapping ("/USER") Public classUsercontroller {@RequestMapping ("/add1.do")     Publicstring 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")     PublicModelandview add2 () {Modelandview Mav=NewModelandview ("User_add1"); Mav.addobject ("UserId", 1001); Mav.addobject ("UserName", "Zhang San"); returnMav; } @RequestMapping ("/add3.do")     PublicString ADD3 (model model) {Model.addattribute ("PersonId", 9527); Model.addattribute ("PersonName", "Tong Pak Fu"); return"User_add1"; } @RequestMapping ("/add4.do")     PublicString add4 (map<string, object>map) {        //this is not accessible;SYSTEM.OUT.PRINTLN ("-----" + map.get ("PersonId"))); Map.put ("PersonId", 9528); Map.put ("PersonName", "Tong Pak Fu 1"); return"User_add1"; }    }

Spring MVC returns page data