RxJava Pagination with argument from last response

RxJavaPagination.java

public Observable<List<User>> getAllUsers() {
        return getUsersObservable(null)
                .toList()
                .map(lists -> {
                    List<User> combinedList = new ArrayList<>();
                    for (final List<User> list : lists) {
                        combinedList.addAll(list);
                    }
                    return combinedList;
                });
    }

    private Observable<List<User>> getUsersObservable(final String valueForNextPage) {
        return getSingleUsersObservable(valueForNextPage)
                .filter(userList -> !isLastPage(userList))
                .flatMap(this::getNextPageUsersObservable);
    }

    private boolean isLastPage(final List<User> userList) {
        return userList.isEmpty();
    }

    private Observable<List<User>> getSingleUsersObservable(final String valueForNextPage) {
        return restAdapter.getData(valueForNextPage);
    }

    private Observable<List<User>> getNextPageUsersObservable(final List<User> userList) {
        Observable<List<User>> mediaResponseObservable = Observable.just(userList);
        User lastUser = userList.get(userList.size() - 1);
        return Observable.merge(getUsersObservable(lastUser.getId()), mediaResponseObservable);
    }

You have an issue line 15. You miss the last page. A fix can be to change behaviour of getNextPageUsersObservable() to check if next exists and return only mediaResponseObservable if not.

Thanks for your snippet very helpful for me