Hangzhou airport to Shanghai

We (3 of us) are flying in to xiaoshan airport at around 18.10. We would like to spend 3 days in Shanghai. Would we be able to take the shuttle bus from airport to Shanghai directly , or do we have to get to downtown and catch a train. How easy is it to get a train ticket to Shanghai and back during the pre-chinese New Year time.
Thank you in advance for your information
from Le Binh in Munnich Germany