数据输出机制之Model、Map及ModelMap回顾

我们用不同的方式来实现数据的 传递：

package com.lagou.edu.controller;

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


import java.util.Date;
import java.util.Map;


/**
* @author lyj
* @Title: DemoController
* @ProjectName springmvc-demo
* @Description: TODO
* @date 2020/6/9 21:21
*/
@Controller
@RequestMapping("/demo")
public class DemoController {
    /**
     * http://localhost:8080/demo/handle01
     */
    @RequestMapping("/handle01")
    public ModelAndView handle01(){
        Date date=new Date();


        ModelAndView modelAndView=new ModelAndView();
        modelAndView.addObject("date",date);
        modelAndView.setViewName("success");
        System.out.println("modelAndView----"+modelAndView.getClass());


        return modelAndView;
    }


    /**
     * http://localhost:8080/demo/handle02
     */
    @RequestMapping("/handle02")
    public String handle02(ModelMap modelMap){
        Date date=new Date();


        modelMap.addAttribute("date",date);
        System.out.println("modelMap------"+modelMap.getClass());


        return "success";
    }


    /**
     * http://localhost:8080/demo/handle03
     */
    @RequestMapping("/handle03")
    public String handle03(Model model){
        Date date=new Date();
        model.addAttribute("date",date);
        System.out.println("model-----"+model.getClass());


        return "success";
    }
    /**
     * http://localhost:8080/demo/handle04
     */
    @RequestMapping("/handle04")
    public String handle04(Map<String,Object>map){
        Date date=new Date();
       map.put("date",date);
        System.out.println("map------"+map.getClass());


        return "success";
    }
}

下面我们来看输出结果：

modelAndView----class org.springframework.web.servlet.ModelAndView
modelMap------class org.springframework.validation.support.BindingAwareModelMap
model-----class org.springframework.validation.support.BindingAwareModelMap
map------class org.springframework.validation.support.BindingAwareModelMap

说明他们最后都是执行的BindingAwareModelMap
ModelMap:

LinkedHashMap是jdk里面的 package java.util;

Model:

Map:

Map也是java.util下面的

BindingAwareModelMap