java - Opposite of broadcast -

i can create source, has integers {1, 2, 3} , using broadcast create me n sources, , each have {1, 2, 3}.

i want opposite, have n sources , each should provide same integers {1, 2, 3} , using ??? want create single source, have {1, 2, 3}.

i call operation ??? "implode" not have better name.

to answer obvious question comes mind: "why weird thing , not take of sources" have note, n sources expected provide same data, in practice may not respond @ all. if respond different data? error violates our business logic, throwing exception ok.

example: have 2 sources (a , b) of integers, , both have {1, 2, 3}. ask both of them @ same time integer. source b responds faster integer 1, imploded source respond 1 (without waiting answer source a).

now ask both sources next element, , time responds faster 2 (i ignoring it's 1) , returning 2 without waiting b.

now ask both sources next element, , throws connectionlostbecausereasonsexception b responds 3 imploded source returns 3 , ok.

so here advantage speed - imploded source fast fastest sources aggregate plus shields me exceptions n-1 sources.

in end, trying implement function like:

<t> source<t, ?> implode(list<source<t, ?>> sources); 

the closest got using zip - wait results n sources, , (by using function) return of them. shield me exceptions, makes me fast slowest one, , isn't want.

is there implemented strategy mine "implode"? if yes, it's name? if no, how should implement myself?

here have tried:

class multi {        static <t> source<t, ?> merger(list<source<t, ?>> sources)     {         switch(sources.size())         {             case 0: throw new runtimeexception("no sources provided!");             case 1: return sources.get(0);             default: return source.zipwithn(multi::zip, sources);         }     }      private static <t> t zip(list<t> list)     {         return list             .stream()             .reduce(multi::same)             .orelsethrow(runtimeexception::new);     }      private static <t> t same(t first, t second)     {         if(objects.equals(first, second))         {             return first;         }         else         {             throw new runtimeexception();         }     }      public static void main(string[] args)     {         source<integer, ?> source1 = source.from(arrays.aslist(1, 2, 3, 4));         source<integer, ?> source2 = source.from(arrays.aslist(1, 2, 3));         source<integer, ?> merger = merger(arrays.aslist(source1, source2));          merger             .runforeach(system.out::println, actormaterializer.create(actorsystem.create()))             .thenrun(() -> system.out.println("done"));     } } 

this code outputs: 1 2 3 done

and like: 1 2 3 4 done

however, zip method called 3 times, don't chance so. second problem wait sources, instead of returning value fast can. covers case of throwing exception when values different, therefore

source<integer, ?> source1 = source.from(arrays.aslist(1, 2, 4)); source<integer, ?> source2 = source.from(arrays.aslist(1, 2, 3));  

outputs: 1 2 exception

as expected.