Swedish citizen transits thru Shanghai to Sydney-do I need to apply for transit visa pre-departure?

I am flying to Sydney via Shanghai with a one-night stop-over. Can I apply for a 72-hour free transit at my port of arrival? Or do I need to apply in Sweden before I board my flight? I am planning to stay within Shanghai for a quick visit before travelling onwards to Australia. Likewise, I am travelling through Beijing on my way back with confirmed flights and seat allocation on my flight to Copenhagen. Thanks for your help with clarifying this issue.

/Martina from Sweden