var http = require("http");
const postData = JSON.stringify({
  'msg' : 'Hello World!'
});

const options = {
  hostname: 'nodejs.cn',
  port: 80,
  path: '/api/',
  method: 'GET',
  headers: {
    'Content-Type': 'application/x-www-form-urlencoded',
    'Content-Length': Buffer.byteLength(postData)
  }
};

const req = http.request(options, (res) => {
  console.log(`状态码: ${res.statusCode}`);
  console.log(`响应头: ${JSON.stringify(res.headers)}`);
  res.setEncoding('utf8');
  res.on('data', (chunk) => {
    //console.log(`响应主体: ${chunk}`);
  });
  res.on('end', () => {
    console.log('响应中已无数据。');
  });
});

req.on('error', (e) => {
  console.error(`请求遇到问题: ${e.message}`);
});
console.log(req.agent.sockets["nodejs.cn:80:"][0].asyncId);
// 写入数据到请求主体
req.write(postData);
req.end();