Their are no direct flights.
Most fly the route with "Qantas": Melbourne - Sydney - Frankfurt - Munich
Total flying time is about 23 hours
Others fly with "Emerates": Melbourne - Singapore - Dubai - Munich
Total flying time is about 22 hours
Others with "Star Allianz": Melbourne - Singapore - Munich
Total flying time is about 21 hours
Normally it takes 10+ hours from Melbourne to Shanghai, yet it still depends on the different situation
an example:
The results of your search for Melbourne (MEL) to Shanghai (SHA)
Shortest Flight Duration 13 hours 40 mins
Depending on flights, straight through would be around 15 hours and 30 minutes. It could take a much longer or shorter time depending on lay overs and/or faster planes.
About 16 hours
About 20 hours.
It will take about 9 hours.
it will take 1 to 2hours
About 24 hours
22 hours
About 5 hours.
19 hours
8h
It will take about 9 hours.
approximately 3 hours
approximately 3 hours
It will be about NaN hours.
2 hrs