Nested Lists In Firebase

Trying to understand how to implement nested lists in Firebase. Problem reducible to: a 1-to-N messaging system, where, for each message, you wish to maintain a list of users who h

Solution 1:

Ah, just needed to use Map instead of List.

In my case:

publicclassMessage {
  privateLong authorID;
  privateString msg;
  privateMap<String, Boolean> receivedBy;
  privateMap<String, Boolean> readBy;
}

Now I understand how to use recursive structures with Firebase. Guess like most things, it is easy -- once you know how.