Export of my JShell session from the Exploring reactive programming in Java talk at Devoxx Ukraine 2019.

devoxx-exploring-reactive.jsh

Thread t = new Thread(() -> System.out.println("hello guadalajara"))
t.start()
ExecutorService e = Executors.newSingleThreadExecutor()
Future<String> f = e.submit(() -> "hello guadalajara")
f
f.get()
ExecutorService e = ForkJoinPool.commonPool()
Future<String> f = e.submit(() -> "hello guadalajara")
f.get()
CompletableFuture<String> cf = new CompletableFuture<String>()
cf.complete("done")
cf.get()
CompletableFuture<String> cf = new CompletableFuture<String>()
cf.get()
cf.completeExceptionally(new IllegalStateException())
cf.get()
CompletableFuture.supplyAsync(() -> "hello")
.thenApplyAsync(x -> x + " guadalajara")
.thenAcceptAsync(System.out::println)
/l
CompletableFuture<String> cf = new CompletableFuture<String>()
cf.completeOnTimeout("timed out", 5, TimeUnit.SECONDS)
cf.get()
CompletableFuture<String> cf = new CompletableFuture<String>()
cf.orTimeout(5, TimeUnit.SECONDS)
cf.get()
CompletableFuture<String> cf = new CompletableFuture<String>()
CompletableFuture<String> copy = cf.copy()
cf.complete("done")
cf
copy
copy.get()
CompletableFuture<String> cf = new CompletableFuture<String>()
CompletableFuture<String> copy = cf.copy()
copy.complete("done")
copy
cf
class SimpleSubscriber implements Subscriber<String> {


}
class SimpleSubscriber implements Subscriber<String> {

public void onSubscribe(Subscription sub) {}

public void onNext(String item) {}

public void onError(Throwable t) {}

public void onComplete() {}

}
/ed SimpleSubscriber
SimpleSubscriber sub = new SimpleSubscriber()
SubmissionPublisher<String> pub = new SubmissionPublisher<String>()
pub.subscribe(sub)
pub.getSubscribers()
pub.submit("hello guadalajara")
pub.close()
pub.submit("hello guadalajara")
HttpHandler handler = he -> {
String body = "hello guadalajara";
he.sendResponseHeaders(200, body.length());

try (OutputStream os = he.getResponseBody()){
os.write(body.getBytes());
}

}
/l handler
HttpServer hs = HttpServer.create(new InetSocketAddress(8000), 0)
hs.createContext("/hello", handler)
hs.start()
HttpClient hc = HttpClient.newHttpClient()
hc.version()
HttpRequest request = HttpRequest.newBuilder().uri(URI.create("http://localhost:8000/hello")).GET().build()
HttpResponse<String> response = hc.send(request, BodyHandlers.ofString())
response.statusCode()
response.body()
CompletableFuture<HttpResponse<String>> response = hc.sendAsync(request, BodyHandlers.ofString())
response.get().body()