Scala/Play/Nginx: static resource routing

Question

I've got my Play app running:

http://localhost:9000

Nginx is proxy passing it to this url:

http://localhost/Demo/

I have a problem with static assets though. For instance, this asset in html template

<link rel="stylesheet" media="screen" href="@routes.Assets.at("stylesheets/main.css")">

is going to

http://localhost/assets/stylesheets/main.css

and obviously results in not being found. If I change it to this (add /Demo in front of the url):

<link rel="stylesheet" media="screen" href="/Demo@routes.Assets.at("stylesheets/main.css")">

it will now correctly go to this url:

http://localhost/Demo/assets/stylesheets/main.css

My question is: how can I add this /Demo to all my static assets without hard codding it into my templates? I prefer to solve this using Play's routing and limit changes done to nginx conf.

I've tried adding a url prefix into application.conf like this

application.context="/Demo"

but that affected all urls not only the static ones, so not a solution. Any thoughts?

My stack: Play Framework 2.2.1 / Scala 2.10.3 / Java 8 64bit / Nginx 1.4.3 / Ubuntu 13.10 64bit

UPDATE: SOLUTION Thanks to @biesior for providing the Java version, I've converted it to scala:

package core

import controllers.routes

object Assets {

    def at(path: String): String = {
        "/Demo" + routes.Assets.at(path)
    }

}

Answer 1

Just overwite the path using own implementation of assets (ie. in utils package):

package utils;
import controllers.routes;

public class MyAssets {
    public static String at(String path){
        return "/Demo"+ routes.Assets.at(path).toString();
    }
}

in templates:

<img src='@utils.MyAssets.at("images/logo.png")' alt="">

On the quite other hand, will target project also work in subdirectory ? If not it's just easier to use subdomains, it's possible also with localhost, just configure your nginx for that project to use ie.: http://demo.loc instead od http://localhost/Demo and add this 'domain' to your hosts file