Anyone have exlerience with layover flightswith a stop in China.

Me friends are booking a trip to Japan. We're based in Europe and the cheapest option for flights involve a 2 hour-ish stop in Chinese airports. Im curious as to the process. One of my friends say you have to get your picture and fingerprints taken. And although Im sceptical of this, Google seems to echo the same idea. Can someone with actual experience in this department summarise what it would actually be like? It'd be very much appreciated. In my mind its not a big deal even if true, but its difficult convince others to think the same way in that regard. Cheers in advance.

Edit: man I really butchered that title, sorry.