小知识点

Map、Model（map、model里面的数据会被放在request的请求域 request.setAttribute）、Errors/BindingResult、RedirectAttributes（重定向携带数据）、ServletResponse（response）、SessionStatus、UriComponentsBuilder、ServletUriComponentsBuilder

Map<String,Object> map, Model model, HttpServletRequest request 都是可以给request域中放数据，

示例

 @GetMapping("/params")
    public String testParam(Map<String,Object> map, Model model, HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse){
    
    
        map.put("hello","thisworld");
        model.addAttribute("model","this is model");
        Cookie cookie=new Cookie("c1","v1");
        cookie.setDomain("localhost");
        httpServletResponse.addCookie(cookie);


        return "forward:/success";
    }

Map和Model的数据会存放在request请求域中
在这里插入图片描述
获取请求域数据

@ResponseBody
    @GetMapping("/success")
    public Map success(@RequestAttribute(value = "msg",required = false) String msg,
                       @RequestAttribute(value = "code",required = false)Integer code,
                       HttpServletRequest request){
    
    
        Object msg1 = request.getAttribute("msg");

        Map<String,Object> map = new HashMap<>();
        Object hello = request.getAttribute("hello");
        Object world = request.getAttribute("world");
        Object message = request.getAttribute("message");

        map.put("reqMethod_msg",msg1);
        map.put("annotation_msg",msg);
        map.put("hello",hello);
        map.put("world",world);
        map.put("message",message);

        return map;
    }