How to implement stacking notifications on Android?

Question

Java

Good afternoon. In my application, notifications come one at a time and with different IDs through Firebase and Google Play Services. I need to group incoming notifications like this:

I read the documentation for developers, searched the Internet for questions about stacking notifications, but did not find a solution to my problem. The problem is that I don’t know how to make it so that, let’s say notification A comes as a separate notification, and when the second notification B arrives, let’s say after 10 minutes, then both notifications are displayed in a single notification, as in the picture. The same with subsequent notices C, D, etc.

Answer 1

The solution turned out to be difficult: to keep notifications in memory every time and when updating, issue new and old