@GetMapping("/request")

    public String hi() {

        HttpClient httpClient = HttpClients.createDefault();

        String url="http://127.0.0.1:8081/response";

        String result=null;

        HttpPost httpPost = new HttpPost(url);

        httpPost.addHeader("Content-type", "application/json;charset=utf-8");

        httpPost.setHeader("Accept", "application/json");

        JSONObject jsonObject = new JSONObject();

        jsonObject.put("request", "hi, i am request!");

        httpPost.setEntity(new StringEntity(jsonObject.toJSONString(), "UTF-8"));

        try {

            HttpResponse response = httpClient.execute(httpPost);

            if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {

                result = EntityUtils.toString(response.getEntity(), StandardCharsets.UTF_8);

            } else {

                result = String.valueOf(response.getStatusLine().getStatusCode());

            }

        } catch (ClientProtocolException e) {

            e.printStackTrace();

        } catch (IOException e) {

            e.printStackTrace();

        }

        return result;

    }

@PostMapping("/response")

    public String response(HttpServletRequest request) throws IOException {

        request.setCharacterEncoding("UTF-8");

        BufferedReader reader = new BufferedReader(new InputStreamReader(request.getInputStream()));

        String temp= null;

        StringBuilder result = new StringBuilder();

        try {

            while ((temp = reader.readLine()) != null) {

                result.append(temp);

            }

        } catch (IOException e) {

            e.printStackTrace();

        }

        reader.close();

        @SuppressWarnings("unchecked")

        Map<String,String> map = (Map<String,String>)JSON.parse(result.toString());

        return "Hi, request,I am response, this message is from you: "+map.get("request");

    }