Rxjava: Transform exception

[dsvoronin]

My case: on deepest layer of app i create Observable. On upper layers i transform given observable with some operators, and also i need to wrap error there.
How can i achieve that, not using another Observable.create() wrap?

[zsxwing]

Could you provide some codes to clarify your question?

[dsvoronin]

sure.

i create observable for my local datastore in android:

 Observable.create((Subscriber<? super T> subscriber) -> {
      try {
        noSQL.using(type).bucketId(bucket).entityId(id).retrieve(noSQLEntities -> {
          if (noSQLEntities.size() == 0) {
            subscriber.onError(
                new DataNotFoundException("Item not found in local NoSQL Storage: id = " + id));
          } else {
            subscriber.onNext(noSQLEntities.get(0).getData());
            subscriber.onCompleted();
          }
        });
      } catch (Throwable e) {
        subscriber.onError(e);
      }
    })

on upper level i need something like this

myObservable.mapException(throwable -> new RepositoryException(throwable))

I can transform emitted items on any point, why i cant do it for exception? Or i can?

[zsxwing]

You can use onErrorResumeNext, such as myObservable.onErrorResumeNext(throwable -> Observable.error(new RepositoryException(throwable))

[dsvoronin]

@zsxwing Thanks! It's exactly what i need.