如何在Node.js中处理POST请求主体

Question

如果我的请求是这样的：POST {url} / lock？device_id =“设备ID”

然后应该在我的浏览器中同时显示发件人的ID [“与发件人的IP地址相关的第一个ID”，“发件人ID 2”]和收件人，同时显示以下内容：

{

 'senders':["4678nsdndcuiehcieocjieieuch-cnisnce",
            "siaducicjockeickoqdkcsklcokcoiekrcoi"],

 'receivers':["wi783jwokejdjnlxwpjepjidijeeddewded"]

}

然后我创建一个服务器，并为该设备获取发件人，并为该设备获取收件人。关于设备的POST锁发件人和/或收件人的问题。

http.createServer(function (req, res) {

  let res_data = {};

  if (req.url === "/devices") {
    const addr = req.client.remoteAddress;
    console.log("Client connected with remote address " + addr);
    subscribers[addr] = {};
    subscribers[addr].req = req;
    subscribers[addr].res = res;
    update_subscriber(req, res);
  }

  else if (req.url.startsWith("/status")){

    res.writeHead(200, {
      "Content-Type":"application/json",
      "Cache-Control":"no-cache",
      "Connection":"close",
      "Access-Control-Allow-Origin": '*',
    });

    const queryParams = getQueryParams(req.url);

    if (queryParams.device_id) {
      res_data.alive = (db.utils.get_service_ids().indexOf(queryParams.device_id) >= 0);
      res.write(`${JSON.stringify(res_data)}\n\n`);
    }

    res.end();

  }

  else if (req.url.startsWith("/receivers") || req.url.startsWith("/senders")) {

    const action = req.url.split("?")[0].split("/").slice(-1)[0];

    res_data[action] = [];

    res.writeHead(200,{
      "Content-Type":"application/json",
      "Cache-Control":"no-cache",
      "Connection":"close",
      "Access-Control-Allow-Origin": '*',
    });

    const queryParams = getQueryParams(req.url);

    if(queryParams.device_id){

      const service_name = db.utils.get_service_name(queryParams.device_id);

      if(db.services.hasOwnProperty(service_name)){
        const service_urls = db.services[service_name].urls;

        if (!service_ok(service_name)) {
          db.utils.remove_service(service_name);
          notify_all();
        }
        else {
          query_node(service_name, service_urls[0], action).then(_ => {
            res_data[action] = db.utils.get_agents(service_name,action);
            res.write(`${JSON.stringify(res_data)}\n\n`);
            res.end();
          });
        }        
      }
      else {
        res.write(`${JSON.stringify(res_data)}\n\n`)
        res.end();
      }
    }
  }
  else if ((req.url.startsWith("/lock") || req.url.startsWith("/release")) && req.method === "POST") {


    //I should write code related that my problem in here//

    let data = '';
    req.on('data', chunk => {
      data += chunk;
    });
    req.on('end', () => {
      if (data.length > 0) {

         const action = req.url.split("?")[0].split("/").slice(-1)[0];
         res_data[action] = [];

         res.writeHead(200,{
          "Content-Type":"application/json",
          "Cache-Control":"no-cache",
          "Connection":"close",
          "Access-Control-Allow-Origin": '*',
         });

         const queryParams = getQueryParams(req.url);

         if(queryParams.device_id){

           const service_name = db.utils.get_service_name(queryParams.device_id);

          if(db.services.hasOwnProperty(service_name)){
             const service_urls = db.services[service_name].urls;

             if (!service_ok(service_name)) {
               db.utils.remove_service(service_name);
               notify_all();
             }
             else {
               query_node(service_name, service_urls[0], action).then(_ => {
                   res_data[action] = db.utils.get_agents(service_name,action);
                  res.write(`${JSON.stringify(res_data)}\n\n`);
                  res.end();
               });
             }
           }
           else {
             res.write(`${JSON.stringify(res_data)}\n\n`);
             res.end();
           }
         }
        JSON.parse(data);
        console.log(data);
      }
    });

  }
  else {

    res.writeHead(400,{
      "Content-Type":"application/json",
      "Cache-Control":"no-cache",
      "Connection":"close",
      "Access-Control-Allow-Origin": '*',
    });

    res.write(`{'error':"Request could not be interpreted by the server."}\n\n`);
    res.end();
  }
}).listen(8844, "127.0.0.1");