Capture paramether from router in beforeAction

Is there a way to capture parameter from router in the beforeAction, so it could be use by all functions in controller?

I have this router:

h ttp://<user:\w+>.' . $domain . '/<controller:\w+>/<action:\w+>' => '<controller>/<action>'

I want to use <user:\w+> as ID in all functions in controller, and make it available without injecting it into the function? Is this possible?