Do I require transit visa for 14 hours?

Hello there, I am departing from Sydney transiting through shanghai airport. Where I have to stopover for 14 hours. My next connecting flight is Tokyo then final destination Mexico. It is my round trip. I am also Bangladesh national. I have valid Australian student visa also Mexican tourist valid visa. Going through China (Shanghai)- 14 hour overnight connection in China, then 2.5 hours connection in Tokyo, fly to Mexico. All one ticket. Please someone answer me. Someone please reply me ASAP my ID :mdshakil66gmail.com

Please guys do not give me a link. It's hard to find