Spring MVCModel、Map及ModelMap幾種方式

Spring MVC輸出數據的幾種方式

@RequestMapping("/handle01")
    public ModelAndView handle01(){
        LocalDateTime now = LocalDateTime.now();
        //封裝頁面與數據
        ModelAndView modelAndView = new ModelAndView();
        modelAndView.addObject("date",now);
        //封裝跳轉的頁面
        modelAndView.setViewName("success");
        System.err.println("==========ModelAndView======== "+modelAndView.getClass());
        return  modelAndView;
    }

    @RequestMapping("/handle11")
    public String handle11(ModelMap modelMap){
        LocalDateTime now = LocalDateTime.now();
        modelMap.addAttribute("date",now);
        System.err.println("==========modelMap======== "+modelMap.getClass());
        return  "success";
    }

    @RequestMapping("/handle12")
    public String handle12(Model model){
        LocalDateTime now = LocalDateTime.now();
        model.addAttribute("date",now);
        System.err.println("==========model======== "+model.getClass());
        return  "success";
    }
    @RequestMapping("/handle13")
    public String handle12(Map<String,Object> map){
        LocalDateTime now = LocalDateTime.now();
        map.put("date",now);
        System.err.println("==========map======== "+map.getClass());
        return  "success";
    }

• ModelAndView
• ModelMap
• Model
• Map
  都可以成功跳轉到指定頁面

==========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

後面3個都是BindingAwareModelMap,數據都會被放在這個中

類結構圖

BindingAwareModelMap是最底層的最後都要轉換爲BindingAwareModelMap
ModelMap Model Map最後都到轉換爲BindingAwareModelMap