如何在node.js的http响应中获取主机名？

Question

I am using http module of node.js for making a request. I have bunch of urls in database. I am fetching these urls from database and making requests in loop. But when response comes, I want to get host name of that response, because I want to update something in database based on that response. But I am not getting for which site I am getting response, so I am unable to update record for that site.

Code is something like this:

for (site = 0; site < no_of_sites; site++) {
    options = {
        hostname: sites[site].name,
        port: 80,
        method: 'GET',
        headers: {
            'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; rv:11.0) Gecko/20100101 Firefox/11.0'
        }
    };

    var req = http.request(options, function (res) {
        console.log('HEADERS: ' + JSON.stringify(res.headers));
        if (res.statusCode == 200) {

            //Update record;
        }
    });
}

Answer 1

Option one : use res.req

var req = http.request(options, function (res) {
  console.log(res.req._headers.host)
});

Option two : use a closure

for (site = 0; site < no_of_sites; site++) {
    (function(){
        var options = {
            // ...
        };

        var req = http.request(options, function (res) {
            // options available here
            console.log(options);
        });
    }());
}

Option three :

It seems this is the same as res.req in the http.request() callback, but I'm not completely sure.

Answer 2

我们可以在this对象中获得宿主站点。

console.log(this._header.match(/Host\:(.*)/g));

Answer 3

答案是console.log（res.socket._httpMessage._headers.host）;