Nested Lists in Firebase [duplicate]

Answer 1

Ah, just needed to use Map instead of List.

In my case:

public class Message {
  private Long authorID;
  private String msg;
  private Map<String, Boolean> receivedBy;
  private Map<String, Boolean> readBy;
}

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