如何用Node.js接收通过POST方法发送的跨域请求

const http = require('http');

const server = http.createServer((req, res) => {
  if (req.method === 'POST') {
    let body = '';
    req.on('data', data => {
      body += data;
    });
    req.on('end', () => {
      console.log(body);
      res.end();
    });
  }
});
server.listen(8080);

const http = require('http');

const clientReq = http.request({
  method: 'POST',
  hostname: 'yourapi.com',
  path: '/path/to/api',
  headers: {
    'Content-Type': 'application/json'
  }
}, (res) => {
  res.on('data', (data) => { /* do something */ });
});

clientReq.on('error', (error) => { /* handle error */ });

process.stdin.on('data', (chunk) => {
  clientReq.write(chunk);
});

process.stdin.on('end', () => {
  clientReq.end();
});

const http = require('http');
const querystring = require('querystring');

const postData = querystring.stringify({
  'msg': 'Hello World!'
});

const options = {
  hostname: 'localhost',
  port: 8080,
  path: '/proxy',
  method: 'POST',
  headers: {
    'Content-Type': 'application/x-www-form-urlencoded',
    'Content-Length': Buffer.byteLength(postData)
  }
};

const req = http.request(options, (res) => {
  res.setEncoding('utf8');
  res.on('data', (chunk) => {
    console.log(`BODY: ${chunk}`);
  });
  res.on('end', () => {
    console.log('No more data in response.')
  })
});

req.on('error', (e) => {
  console.error(`problem with request: ${e.message}`);
});

// 请求的数据
req.write(postData);
req.end();