can i get a multiple entery visa for 6 months in china as a canadian citizen

Im trying to figure out if i can get a multple entry visa to china as i am going to visit friends (specifically girl friend). I then want to go to thailand and do some diving and then back to china to visit friends again and travel around seeing everything that asia offers. I dont want to limit my accessibility to surrounding countries as im not sure where i may end up because of chinese new years my girlfirend wont know her holiday scedule untill shortly before the actual holiday. do i need to provide info for all my flights before i get a visa? any insite would be very helpfull.