使req.host /点播。当Express后台代理时，主机名有效必须满足两个条件:

App.set('信任代理'，'环回');在app.js x - forward - host头必须由你自己在webserver中指定。如。apache, nginx

nginx:

server {
    listen myhost:80;
    server_name  myhost;
    location / {
        root /path/to/myapp/public;
        proxy_set_header X-Forwarded-Host $host:$server_port;
        proxy_set_header X-Forwarded-Server $host;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_pass http://myapp:8080;
    }
}

apache:

<VirtualHost myhost:80>
    ServerName myhost
    DocumentRoot /path/to/myapp/public
    ProxyPass / http://myapp:8080/
    ProxyPassReverse / http://myapp:8080/
</VirtualHost>

我使用节点包'url' (npm install url)

它的作用是当你打电话的时候

url.parse(req.url, true, true)

它将给你检索url的全部或部分的可能性。更多信息请访问:https://github.com/defunctzombie/node-url

我以以下方式使用它来获取http://www.example.com/中/之后的任何内容作为变量并拉出特定的配置文件(有点像facebook: http://www.facebook.com/username)

    var url = require('url');
    var urlParts = url.parse(req.url, true, true);
    var pathname = urlParts.pathname;
    var username = pathname.slice(1);

不过，为了实现这一点，你必须在server.js文件中以这种方式创建路由:

self.routes['/:username'] = require('./routes/users');

这样设置你的路由文件:

router.get('/:username', function(req, res) {
 //here comes the url parsing code
}

通常我依赖这2个，取决于服务器和代理是否存在:

req.socket.remoteAddress

req.headers.referer

const fullUrl = `${protocol}://${host}:${port}${url}`
      
    const responseString = `Full URL is: ${fullUrl}`;                       
    res.send(responseString);  
})

你需要使用req.headers.host + req.url来构造它。当然，如果你是在不同的端口，你得到的想法;-)

你可以从req of express得到完整的url。

function fetchPages(req, res, next) {

    let fullUrl = req.headers.host + req.originalUrl;
    console.log("full url ==> ",fullUrl);
}