Cache js files in laravel

CacheJsController.php

<?php
namespace App\Http\Controllers;

use Illuminate\Http\Request;

use App\Http\Requests;

class CacheJsController extends Controller
{

    function __construct()
    {

    }

    public function cache_js(Request $request, $file)
    {
        $_expires = 20160;

        switch ($file) {
            case 'analytics.js':
                $_remote_file = 'https://www.google-analytics.com/analytics.js';
                break;

            default:
                \App::abort(404);
                break;
        }

        if (!Cache::has($file)) {
            $_remote = file_get_contents($_remote_file);
            $_time = new \DateTime('now');
            Cache::put($file, [$_time, $_remote], $_expires);
        } else {
            $_cache = Cache::get($file);
            $_remote = $_cache[1];
            $_time = $_cache[0];
        }

        $response = Response::make($_remote, 200)
            ->header('Content-Type', 'text/javascript')
            ->header('Cache-Control', 'private, max-age=' . $_expires)
            ->setLastModified($_time)
            ->setExpires(\Carbon\Carbon::now()->addMinutes($_expires));
        return $response;
    }
    
}

routes.php

<?php
// Add this to your routes.php

Route::get('/js/{file}', 'CacheJsController@cache_js');