Router design

index.php

<?php

$router->add('GET', '/user/:userId', /* All callable */, $middleware1, $middleware2, $controller);

try {
    $router->execute($request);    
} catch (\HttpError\Code500 $e) {
    $e->viewMessage();    
} catch (\HttpError\Code403 $e) {
    $e->viewMessage();
} catch (\HttpError\Code401 $e) {
    $e->viewMessage();
} catch (\HttpError\Code400 $e) {
    $e->viewMessage();
} catch (\Exception $e) {
    // general uncaught message
}