Why is the class not in Lavarel?

Question

Laravel

Hello! Can you tell me why this file is throwing an error Class 'app\Http\Controllers\Controller' not found

<?php


namespace App;

use DB;
use app\Http\Controllers\Controller;

class Site extends Controller
{
    function __construct($domainid , $userid , $vhostid)
    {
        $this->domainid = $domainid;
        $this->userid = $userid;
        $this->vhostid = $vhostid;
    }

    /**
     *
     *
     * @return Response
     */
    private function checkbelong ($domainid, $userid , $vhostid)
    {
        $checkdom = DB::table("domain")
            ->select('unid')
            ->where("userid",  $userid)
            ->where ("unid" , $domainid)
            ->where("type" , "unlinked")
        ->get();
        $checkvh = DB::table("vhosts")
            ->select('unid')
            ->where("userid",  $userid)
            ->where ("unid" , $vhostid)
            ->get();
        var_dump($checkvh);
if (!$checkvh OR !$checkdom) {return $error = "Trying to link foreign domain";}
else {return true;}
    }
    private function checkexist ($domainid,$vhostid) {
        $checkdom = DB::table("domain")
        ->select('unid')
        ->where ("unid" , $domainid)
        ->where("type" , "unlinked")
        ->get();
        $checkvh = DB::table("vhosts")
            ->select('unid')
            ->where ("unid" , $vhostid)
            ->get();
        if (!$checkvh OR !$checkdom) {return $error = "Trying to link non-existent domain";}
        else {return true;}
    }
}

Empirically found out that this part of the line causes the error: class Site extends Controller

Answer 1

use App capitalized?

Answer 2

Do php artisan make:controller Siteit and see how it should be right, what paths and namespaces should be. And then remove your class and use artisan to create it.
If something is autoloaded and the class is still not found, trycomposer dump-autoload