Is it correct to convert CompletableFuture <Stream <T>> to Publisher <T>?

Question

To allow multiple iterations in the resulting stream from a CompletableFuture<Stream<String>>, I consider one of the following approaches:

• Transform the resulting future into CompletableFuture<List<String>>:teams.thenApply(st -> st.collect(toList()))

• Convert the resulting future to Flux<String>with cache:Flux.fromStream(teams::join).cache();

Flux<T>represents an implementation Publisher<T>in a design reactor.

Use Case:

I would like to get a sequence with the names of the Premier League teams (e.g. Stream<String>) from a data source that provides an object Leaguewith Standing[](based on the RESTful API for football data, e.g. http://api.football-data.org/v1/soccerseasons/445 / leagueTable ). Using AsyncHttpClientand Gson, we have:

CompletableFuture<Stream<String>> teams = asyncHttpClient
    .prepareGet("http://api.football-data.org/v1/soccerseasons/445/leagueTable")
    .execute()
    .toCompletableFuture()
    .thenApply(Response::getResponseBody)
    .thenApply(body -> gson.fromJson(body, League.class));
    .thenApply(l -> stream(l.standings).map(s -> s.teamName));

, :

1. CompletableFuture<List<String>> res = teams.thenApply(st -> st.collect(toList()))

2. Flux<String> res = Flux.fromStream(teams::join).cache()

Flux<T> , . , ?

CompletableFuture<List<String>> ? ?

(2018-03-16):

CompletableFuture<List<String>>:

• [PROS] List<String> , , , .
• [CONS] .
• [CONS] , List<T>.

Flux<String>:

• [PROS]
• [PROS] , .cache() , API, . , . @GetMapping(produces =MediaType.TEXT_EVENT_STREAM) public Flux<String> getTeams() {…}
• [CONS] Flux<T>, Flux<T> (….cache()), , , , .

Answer 1

, , , . ( ) , , , ?

:

String[] teamNames = teams.join().toArray(String[]::new);