RxJava2 Single take different route based on the item - rx-java2

Question

I have the following code:
Single<Response<User>> single = service.registerUser();
single
.subscribeOn(Schedulers.io())
.observeOn(Schedulers.computation())
.map(Response::body)
.flatMap(parentsRepsitory::writeUser)
.observeOn(AndroidSchedulers.mainThread())
.flatMap(parentsRepsitory::getUser)
Where the parentsRepository is a repo wraping my realm database. The problems come when the server returns validation errors, however. So somewhere in my stream i want to have the equivalent of
if(response.code() == 201){
// CONTINUE STREAM USING THE LOGIC THAT HANDLES SUCCESS
}elseif(response.code() == 400){
// CONTINUE STREAM USING LOGIC TO HANDLE THE VALIDATION ERRORS
}
A solution I have previously implemented is as follows:
Observable<Response<User>> observable_from_api =
service.attemptLogin(username, password)
.share();
observable_from_api
.filter(response -> response.code() == HttpStatus.HTTP_STATUS_200_OK)
.//handle logic for success
observable_from_api
.filter(response -> response.code() == HttpStatus.HTTP_STATUS_400_BAD_REQUEST)
.//handle logic for validation errors
I don't like this solution for several different reasons. The main one being it just does not seem right. The second one being that the .share() method is only available on an Observable object. Since my network operation emits only one responce I would much rather use Single instead, but the .share() method is not available there.
Excuse me if this is a duplicate question, I have done some digging around and only found the solution I mentioned. I want to either see the optimal solution or be told explicitly that this is in fact the optimal solution.

Answer 1

I think you need to define which kind of data you want your consumer to receive. I assume you want to receive in the consumer a User object.
These are the signatures of the method that you should create:
Single<User> handleSuccess(Response<User> response)
Single<User> handleError(Response<User> response)
And then you create you stream in this way:
service.registerUser()
.flatMap(response -> {
if (response.success) {
return handleSuccess(response);
} else {
return handleError(response);
}
})
.subscribe(user -> logd("user: " + user.name));