RxJava - How to take the first element of a list and return it as Observable

Question

Let's take this observable:

Observable<List<UserProfile>> findUser =service.getUserProfiles()

How can I transform it so it returns the first element as an Observable (and not an Observable list just containing the first element). I tried first() and takeFirst() but it still returns a list.

Answer 1

Map it!

Observable<List<UserProfile>> findUser = service.getUserProfiles();
Observable<UserProfile> firstUser = findUser
    .filter(list -> !list.isEmpty())
    .map(list -> list.get(0));