express里http.createServer和app.listen有什么区别？ – CNode技术社区

搜了一下，并看了koa和express这部分的代码：
koa:
/**
* Shorthand for:
*
* http.createServer(app.callback()).listen(…)
*
* @param {Mixed} …
* @return {Server}
* @api public
*/

listen() {
  debug('listen');
  const server = http.createServer(this.callback());
  return server.listen.apply(server, arguments);
}

express:
/**
* Listen for connections.
*
* A node http.Server is returned, with this
* application (which is a Function) as its
* callback. If you wish to create both an HTTP
* and HTTPS server you may do so with the “http”
* and “https” modules as shown here:
*
* var http = require(‘http’)
* , https = require(‘https’)
* , express = require(‘express’)
* , app = express();
*
* http.createServer(app).listen(80);
* https.createServer({ … }, app).listen(443);
*
* @return {http.Server}
* @public
*/

app.listen = function listen() {
  var server = http.createServer(this);
  return server.listen.apply(server, arguments);
};

综合koa和express的代码，可以看出，没有区别，但是这两个框架默认都是使用http，若使用https则需要自己收写。