Do I required transit visa for 14 hours stopover?

Hi I have layover 14 hours in shanghai airport . I am Bangladeshi national but have Australian valid student visa also have Mexican valid tourist visa. I am departing from Sydney, Australia. Do I have to obtain a transit G for overnight. Though I am not planning to go outside of the airport. My next connective flight is Tokyo. I am getting all one ticket. Someone please help me ASAP