Hi, there is a shuttle bus provided by Air Asia from Hangzhou airport to Shanghai after the flights. If your airline is AirAisa, you can try to book the ticket in advance. If not, you can have try to take it if there is left seat on the bus. Otherwise, you need to go to Hangzhou railway station to take train to Shanghai. I advise you to stay in Hangzhou for one night, the next day you can take bullet train to Shanghai.