What languages are spoken in Barcelona Spain?

Spanish and Catalan.

Either spanish or catalan. Depends on the person you talk to.
Spanish and Catalan.
The language spoken in Barcelona is Catalan.
Catalan is the official language of the Spanish Autonomous Community of Catalunya, of which Barcelona is the capital and largest city.

However, Castellano is widely spoken in Barcelona. If one is traveling to Barcelona they will encounter absolutely no issues being understood and understanding people.

However, one should be aware that this is an area of cultural sensitivity and to remain "outside" of the debates between Castellano and Catalan.

On a plus side, English will be accepted and in most areas, a modicum, if not fluent English will be available in all of the tourist areas.