Samsung Galaxy 2 stuck at start up. Can I recovery the phone or at least the data?

My Samsung Galaxy 2 stuck every time when start up. It looks ok on the beginning, it shows "Samsung Galaxy S II ..." then change display to Vodafone logo then the shows word "samsung" and stuck here forever. It does not respond to any key after that. To shut it down I need to take the battery off. My questions are if I can recovery the operational system or at least data from the phone.