java - Can't catch the custom exception in the onError() method in Rxjava -

i want deal exception myself , example ,show proper toast, write responsefunc below:

public final class responsefunc<t> implements func1<baseresponse<t>, observable<t>> {  @override public observable<t> call(baseresponse<t> response) {     if (!response.issuccess()) {          switch (response.geterror().getcode()) {             case 404: {                 throw new errorresponseexception("say sorry"));             }              // , many other case here 404 500...                   default: {                 return observable.error(new errorresponseexception(response.geterror().getmessage()));             }         }     } else {         return observable.just(response.getdata());     } } } 

ps: here errorresponseexception extends runtimeexception

but can't message "say sorry" or other exceptions thrown myself in subscriber's onerror() method (or observer's onerror() method).

when print stack traces ,it shows original exception , error message

for more details : basic response quite simple , :

{data : t , error{code : int , message : string}, succeed : boolean}

and use responsefunc in flatmap()method everywhere :

service.dosomething()             .flatmap(new responsefunc<>())             .compose(new schedulertransformer<>()); 

i don't know going wrong.but if feels wrong , 😭

could plz give me advices, thx in advance.