JShell transcript from the Exploring reactive programming in Java session at VoxxedDays Bristol 2018.

voxxed-bristol-reactive.jsh

Thread t = new Thread(() -> System.out.println("hello bristol"))
t.start()
ExecutorService e = Executors.newSingleThreadExecutor()
Future<String> f = e.submit(() -> "hello bristol")
f
f.get()
ExecutorService e = ForkJoinPool.commonPool()
Future<String> f = e.submit(() -> "hello bristol")
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 + " bristol").thenAccept(System.out::println)
CompletableFuture.supplyAsync(() -> "hello").thenCombineAsync(CompletableFuture.supplyAsync(x -> x + " bristol"), (x, y) -> x + y).thenAccept(System.out::println)
CompletableFuture.supplyAsync(() -> "hello").thenCombineAsync(CompletableFuture.supplyAsync(() + " bristol"), (x, y) -> x + y).thenAccept(System.out::println)
CompletableFuture.supplyAsync(() -> "hello").thenCombineAsync(CompletableFuture.supplyAsync(() -> " bristol"), (x, y) -> x + y).thenAccept(System.out::println)
CompletableFuture.supplyAsync(() -> "hello").thenCombineAsync(CompletableFuture.supplyAsync(() -> " bristol"), (x, y) -> x + y).exceptionally(t -> "We have an error: " + t.getMessage()).thenAccept(System.out::println)
CompletableFuture.supplyAsync(() -> "hello").thenCombineAsync(CompletableFuture.failedFuture(new IllegalStateException()), (x, y) -> x + y).exceptionally(t -> "We have an error: " + t.getMessage()).thenAccept(System.out::println)
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")
cd
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> {
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")
pub.submit("hello")
pub.submit("hello")
pub.submit("hello")
pub.close()
HttpHandler handler = he -> {
String body = "hello bristol";
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()