Simple Laravel 5 response caching

CacheResponse.php

<?php

namespace App\Http\Middleware;

use Closure;
use Cache;

class CacheResponse
{
    /**
     * Handle an incoming request.
     *
     * @param  \Illuminate\Http\Request  $request
     * @param  \Closure  $next
     * @return mixed
     */
    public function handle($request, Closure $next)
    {

        $key = $this->generateKey($request->fullUrl());

        if (Cache::has($key)) {
            return response(Cache::get($key));
        }

        return $next($request);
    }

    /**
     * Handle caching of a request if it doesn't already exist
     */
    public function terminate($request, $response)
    {
        $key = $this->generateKey($request->fullUrl());

        // if the cache key doesn't exist then we store the whole response
        if (!Cache::has($key)) {
            // cache for 24 hours
            Cache::put($key, $response->getContent(), 1440);
        }
    }

    protected function generateKey($url)
    {
        return 'response_' . str_slug($url);
    }
}