\Drupal\Core\Routing\RouteMatchInterface
$container->get('current_route_match')
/** @var \Drupal\Core\Routing\RouteMatchInterface $currentRouteMatchService */
$currentRouteMatchService = \Drupal::service('current_route_match');
Assume $service = \Drupal::service('current_route_match');
$routeName = $service->getRouteName()
$paramObject = $service->getParameter('route_param')
/user/{uid}
$user = $service->getParameter('user')
returns user object (Drupal\user\Entity\User) for {uid} value