SpringMVC 之POST 和GET 获取参数总结

SpringMVC之GET 请求参数获取方式

方式一：直接在方法体中指定参数

eg:

    @GetMapping("/get")
    public User getUserById(Integer id) {
        if (id.intValue() == 0) {
            return null;
        }
        return list.get(id);
    }

HTTP 请求路径= http://ip:port/xx/get?id=1

方式二：使用requestParam

eg:

    @GetMapping("/get")
    public User getUserById(@RequestParam(name = "id", required = true) Integer id) {
        if (id.intValue() == 0) {
            return null;
        }
        return list.get(id);
    }

 注意:RequestParam中name表示url中请求的字段名，当required为true时，表示该参数必填；defaultValue表示当该参数没有传递数据时给出的默认值，如defaultvalue=”0”

HTTP 请求路径= http://ip:port/xx/get?id=1

方式三：使用PathVariable

eg：

    @GetMapping("/get/{id}")
    public User getUserByPathValue(@PathVariable(name = "id", required = true) Integer id)         
    {
        return list.get(id);
    }

注意:该方式用来获取路径中的参数。@PathVariable中的字段含义同RequestParam 

HTTP 请求路径= http:///ip:port/xx/get/1 ——->对应于http:///ip:port/xx/get/{id}

方式四:使用HttpServletRequest

eg:

    @GetMapping("/get")
    public User getUserById(HttpServletRequest request) {
        Integer id = Integer.parseInt(request.getParameter("id"));
        if (id.intValue() == 0) {
            return null;
        }
        return list.get(id);
    }

HTTP 请求路径=http://ip:port/xx/get?id=1

SpringMVC之POST请求参数获取方式

温馨提示:一般而言，post形式的参数被放在请求体中以application/json的形式被后端获取

方式一：获取一个对象

Headers 头部信息设置

SpringMVC 后台Controller层

    @PostMapping("/save")
    public User saveUser(@RequestBody User user) {
        list.add(user);
        return user;
    }

 Postman 模拟请求截图

 方式二：使用Map

 Headers 头部信息设置

 SpringMVC 后台Controller层

   @PostMapping("/save")
     public User saveUser(@RequestBody Map map) {
     Integer id = (Integer) map.get("id");
     String name = (String) map.get("name");
     Integer age = (Integer) map.get("age");
     List hobby=(List) map.get("hobby");
     User user = new User(id, name, age, hobby);
     list.add(user);
     return user;
     }

Postman 模拟请求截图 

  方式三：使用HttpServletRequest

Headers 头部信息设置

  SpringMVC 后台Controller层

     @PostMapping("/save")
     public User save(HttpServletRequest request) {
         Integer id = Integer.parseInt(request.getParameter("id"));
         String name = request.getParameter("name");
         Integer age = Integer.parseInt(request.getParameter("age"));
         String parameter = request.getParameter("hobby");
         User user = new User(id, name, age, null);
         list.add(user);
         return user;
     }

Postman 模拟请求截图

方式四:通过HTTP协议将参数转换为JSONObject 

 Headers 头部信息设置

 SpringMVC 后台Controller层

@PostMapping("/save")
    public User save(HttpServletRequest request) throws IOException, JSONException {

        JSONObject jsonObject = handlerData(request);
        Integer id = jsonObject.getInteger("id");
        String name = jsonObject.getString("name");
        Integer age = jsonObject.getInteger("age");
        List hobby = jsonObject.getObject("hobby", List.class);
        User user = new User(id, name, age, hobby);
        list.add(user);
        return user;
    }
    //这里使用的是alibaba的json工具类
    public static JSONObject handlerData(HttpServletRequest request) throws IOException, JSONException {
        StringBuffer sb = new StringBuffer();
        InputStream is = request.getInputStream();
        BufferedReader br = new BufferedReader(new InputStreamReader(is, "utf-8"));
        String s = "";
        while ((s = br.readLine()) != null) {
            sb.append(s);
        }
        if (sb.toString().length() <= 0) {
            return null;
        } else {
            return JSONObject.parseObject(sb.toString());
        }
    }

Postman 模拟请求截图