There is one shuttle bus everyday operated by Air Asia for their passengers, between Shanghai Huangpu Bus Station and Hangzhou Airport. In the event of flight schedule change, this bus service will depart 1 hour after the arrival of AirAsia X flight.
You may take it if you take Air Asia. Otherwise, you can stay in the airport and take an early morning bus.

Ms ming, by the time you get thru the custom is already 12mid nite. The teksi to Hangzhou train station is 35--40min away. there is no time to catch the last train.