数据怎么存储？

数据存储在request，session，application中

数据在页面怎么获取？

EL表达式

在页面中怎么显示数据

EL + JSP

数据存储跟跳转方式有关

forward 一次请求 request
redirect 多次请求 session 或 application

controller

方法参数中写HttpservletRequest和HttpServletResponse获取各个域

示例

package com.codegzy.controller;

import com.codegzy.entity.User;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.servlet.http.HttpServletRequest;

@Controller
@RequestMapping("/attr")
public class AttrController {

    @RequestMapping("/test1")
    public String test1(HttpServletRequest request){
        //forward跳转 一次跳转 只能用request存储数据
        //普通数据传递数据传递
        String name = "gzy";
        request.setAttribute("username",name);

        //传递对象
        User user = new User("gzy", 166);
        request.setAttribute("user",user);

        return "attr";
    }

    @RequestMapping("/test2")
    public String test2(HttpServletRequest request){
        //redirect跳转 用session或application或?传递数据
        String name = "chris";
        request.getSession().setAttribute("username",name);
        return "redirect:/attr/test1";
    }
}