From the Airport of Barcelona by public transport:
You can take the commuter train (Rodalies de Catalunya) line L9 up to the train stop of Collblanc. Once you have arrived there, you need to take the following path:
Head northeast on Travessera de les Corts/N-340 toward Carrer del Danubi
Turn right onto Carrer de Francesc Layret
Turn left onto Carrer 11 de Setembre
Hola Hostel Collblanc