java - RxJava error handling -

i have method creates , merges 2 observable<t>'s.

private observable<string> getdata() {      observable<string> observable1 = observable.just("just string")             .delay(2, timeunit.seconds);      observable<string> observable2 = observable.create(new observable.onsubscribe<string>() {         @override         public void call(subscriber<? super string> subscriber) {             subscriber.onerror(new exception("oops!"));         }     });      observable<string> merged = observable1.mergewith(observable2);      return merged;         } 

the problem error in observable2 emitted earlier data in observable1.

getdata().subscribe(new observer<string>() {             @override             public void oncompleted() {                 log.d("rx", "oncompleted");             }              @override             public void onerror(throwable e) {                 log.d("rx", "onerror: " + e.getmessage());             }              @override             public void onnext(string s) {                 log.d("rx", "onnext: " + s);             }         }); 

observable2 emitted optional data , errors observable2must not terminate emission, on other hand, want handle errors , data in single observer. can return error after result observable1? possible?

expect results:

onnext: string onerror: oops! 

sounds need observable.mergedelayerror().

it applies merge operation if of observables call onerror, doesn't stop right away captures error(s).

once other observables have gracefully completed, error(s) is(are) propagated, potentially combined single compositeexception.