SpringMVC 之POST 和GET 获取参数总结

谁借莪１个温暖的怀抱￠ 2023-10-10 13:07 8阅读 0赞

## 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][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][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][http_ip_port_xx_get_1] ——->对应于[http:///ip:port/xx][http_ip_port_xx_get_1]/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][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

![2021071822541992.png][]

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

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pob3V6aGl3ZW5nYW5n_size_16_color_FFFFFF_t_70][]

### 方式二：使用Map ###

Headers 头部信息设置

![2021071822541992.png][]

SpringMVC 后台Controller层

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

Postman 模拟请求截图

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pob3V6aGl3ZW5nYW5n_size_16_color_FFFFFF_t_70 1][]

### 方式三：使用HttpServletRequest ###

Headers 头部信息设置

![20210718230003116.png][]

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

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pob3V6aGl3ZW5nYW5n_size_16_color_FFFFFF_t_70 2][]

### 方式四:通过HTTP协议将参数转换为JSONObject ###

Headers 头部信息设置

![2021071822541992.png][]

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<String> 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

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pob3V6aGl3ZW5nYW5n_size_16_color_FFFFFF_t_70 3][]

[http_ip_port_xx_get_id_1]: http://ip/xx/get?id=1
[http_ip_port_xx_get_1]: http://ip/xx/get/1
[2021071822541992.png]: https://img-blog.csdnimg.cn/2021071822541992.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pob3V6aGl3ZW5nYW5n_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20210718225549287.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pob3V6aGl3ZW5nYW5n,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pob3V6aGl3ZW5nYW5n_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/20210718225723489.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pob3V6aGl3ZW5nYW5n,size_16,color_FFFFFF,t_70
[20210718230003116.png]: https://img-blog.csdnimg.cn/20210718230003116.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pob3V6aGl3ZW5nYW5n_size_16_color_FFFFFF_t_70 2]: https://img-blog.csdnimg.cn/2021071823012024.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pob3V6aGl3ZW5nYW5n,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pob3V6aGl3ZW5nYW5n_size_16_color_FFFFFF_t_70 3]: https://img-blog.csdnimg.cn/20210718230413339.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pob3V6aGl3ZW5nYW5n,size_16,color_FFFFFF,t_70