表达4。将http重定向到https。

i have the following code :

我有以下代码:

var https        = require('https');
var http         = require('http');
var express      = require('express');
var app          = express();
var router       = express.Router();

app.use('/', router);

//listen server on https
var server = https.createServer(config.sslCredential, app);
server.listen(config.serverPort);

//listen server on http, and always redirect to https
var httpServer = http.createServer(function(req,res){
    res.redirect(config.serverDomain+req.url);
});
httpServer.listen(config.httpServerPort);
var htt