Java Code Examples for java.util.concurrent.CompletionStage#whenComplete()

The following examples show how to use java.util.concurrent.CompletionStage#whenComplete() . These examples are extracted from open source projects. You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. You may check out the related API usage on the sidebar.
Example 1
protected <R, E extends Throwable> void setupContinuation(Continuation continuation) {
    @SuppressWarnings("unchecked")
    SuspendParams<R> suspendParams = (SuspendParams<R>)continuation.value();
    
    CompletionStage<R> future   = suspendParams.future;
    AbstractAsyncMethod suspendedMethod = suspendParams.suspendedMethod;
    
    ContinuationResumer<? super R, Throwable> originalResumer = new ContinuationResumer<>(continuation);
    Runnable wrappedResumer = suspendedMethod.createResumeHandler(originalResumer);
    // Setup future and give it a chance to continue the Continuation
    try {
        future.whenComplete((r, e) -> {
            originalResumer.setup(r, e);
            wrappedResumer.run();
        });
    } catch (Throwable error) {
        resume(continuation, FutureResult.failure(error));
    }
}
 
Example 2
Source Project: flink   File: GrpcStateService.java    License: Apache License 2.0 6 votes vote down vote up
@Override
public void onNext(StateRequest request) {
  StateRequestHandler handler =
      requestHandlers.getOrDefault(request.getInstructionId(), this::handlerNotFound);
  try {
    CompletionStage<StateResponse.Builder> result = handler.handle(request);
    result.whenComplete(
        (StateResponse.Builder responseBuilder, Throwable t) ->
            // note that this is threadsafe if and only if outboundObserver is threadsafe.
            outboundObserver.onNext(
                t == null
                    ? responseBuilder.setId(request.getId()).build()
                    : createErrorResponse(request.getId(), t)));
  } catch (Exception e) {
    outboundObserver.onNext(createErrorResponse(request.getId(), e));
  }
}
 
Example 3
public static void main(final String[] argv) throws Exception {
	final AsyncAwaitNioFileChannelDemo demo = new AsyncAwaitNioFileChannelDemo();
	final CompletionStage<String> result = demo.processFile("./.project");
	
	System.out.println("Returned to caller " + LocalTime.now());
	final CompletionStage<?> waiter = result.whenComplete((r, e) -> {
		if ( e != null ) {
			System.out.println("Error " +  LocalTime.now());
			e.printStackTrace(System.out);
		} else {
			System.out.println("Result " +  LocalTime.now());
			System.out.println(r);
		}
	});
	
	// Need to wait because NIO uses daemon threads that do not prevent program exit
	System.out.println("Start waiting for result to prevent program close...");
	waiter.toCompletableFuture().join();
	
}
 
Example 4
Source Project: netty-rest   File: HttpServer.java    License: Apache License 2.0 6 votes vote down vote up
void handleAsyncJsonRequest(ObjectMapper mapper, RakamHttpRequest request, CompletionStage apply)
{
    if (apply == null) {
        NullPointerException e = new NullPointerException();
        uncaughtExceptionHandler.handle(request, e);
        LOGGER.error(e, "Error while processing request. The async method returned null.");
        return;
    }
    apply.whenComplete((BiConsumer<Object, Throwable>) (result, ex) -> {
        if (ex != null) {
            while (ex instanceof CompletionException) {
                ex = ex.getCause();
            }
            uncaughtExceptionHandler.handle(request, ex);

            requestError(ex, request);
        }
        else {
            returnJsonResponse(mapper, request, OK, result);
        }
    });
}
 
Example 5
protected static void test(TestContext context, CompletionStage<?> cs) {
	// this will be added to TestContext in the next vert.x release
	Async async = context.async();
	cs.whenComplete( (res, err) -> {
		if ( res instanceof Stage.Session ) {
			Stage.Session s = (Stage.Session) res;
			if ( s.isOpen() ) {
				s.close();
			}
		}
		if ( err != null ) {
			context.fail( err );
		}
		else {
			async.complete();
		}
	} );
}
 
Example 6
protected CompletionStageWrapper(CompletionStage<T> delegate) {
    super(delegate);
    whenDone = new CountDownLatch(1);
    result   = null;
    fault    = null;
    delegate.whenComplete((r, e) -> {
       // It's a responsibility of delegate to call 
       // this callback at most once -- any valid
       // implementation should not invoke callback
       // more than once, so result/fault will not
       // be overwritten
       result   = r;
       fault    = e;
       whenDone.countDown();
    });
}
 
Example 7
@Override
public <U> CompletionStage<U> applyToEitherAsync(final CompletionStage<? extends T> other,
    final Function<? super T, U> fn, final Executor executor) {
  Objects.requireNonNull(fn);
  final SimpleCompletionStage<T> scs = new SimpleCompletionStage<>();

  runOrPush((res, t, exc) -> scs.completeEncoded(res));

  other.whenComplete((t, exc) -> {
    if (exc == null) {
      scs.complete(t);
    } else {
      scs.completeExceptionally(exc);
    }
  });

  return scs.thenApplyAsync(fn, executor);
}
 
Example 8
@Test
public void cancellationOnDependentCancelsSource() throws InterruptedException {
    CountDownLatch cancelLatch = new CountDownLatch(1);
    CompletionStage<String> stage = source.afterCancel(cancelLatch::countDown).toCompletionStage();
    AtomicReference<Throwable> causeRef = new AtomicReference<>();
    CountDownLatch latch = new CountDownLatch(1);
    stage = stage.whenComplete((s, t) -> causeRef.compareAndSet(null, t))
                 .whenComplete((s, t) -> causeRef.compareAndSet(null, t));

    stage.whenComplete((s, t) -> {
        causeRef.compareAndSet(null, t);
        latch.countDown();
    });

    stage.toCompletableFuture().cancel(true);
    latch.await();
    assertThat(causeRef.get(), is(instanceOf(CancellationException.class)));
    cancelLatch.await();
}
 
Example 9
/**
 * Returns a CompletionStage that is recovered from a specific exception.
 *
 * @param completionStage the completionStage which should be recovered from a certain exception
 * @param exceptionType the specific exception type that should be recovered
 * @param exceptionHandler the function applied after callable has failed
 * @return a CompletionStage that is recovered from a specific exception.
 */
public static <X extends Throwable, T> CompletionStage<T> recover(CompletionStage<T> completionStage, Class<X> exceptionType, Function<Throwable, T> exceptionHandler){
    CompletableFuture<T> promise = new CompletableFuture<>();
    completionStage.whenComplete((result, throwable) -> {
        if (throwable != null){
            if (throwable instanceof CompletionException || throwable instanceof ExecutionException) {
                tryRecover(exceptionType, exceptionHandler, promise, throwable.getCause());
            }else{
                tryRecover(exceptionType, exceptionHandler, promise, throwable);
            }

        } else {
            promise.complete(result);
        }
    });
    return promise;
}
 
Example 10
public void apiSchemasPost(AsyncResponse response, NewSchema schema, boolean verify)
throws ArtifactNotFoundException {
    String artifactId = schema.getName();
    if (artifactId == null) {
        artifactId = idGenerator.generate();
    }

    ContentHandle content = ContentHandle.create(schema.getDefinition());

    if (verify) {
        rulesService.applyRules(artifactId, ArtifactType.AVRO, content, RuleApplicationType.CREATE);
        response.resume(Response.ok().entity(content).build());
    } else {
        CompletionStage<ArtifactMetaDataDto> csArtifact = storage.createArtifact(artifactId, ArtifactType.AVRO, content);
        csArtifact.whenComplete((amdd, t) -> {
            if (t != null) {
                response.resume(t);
            } else {
                SchemaInfo info = new SchemaInfo();
                info.setId(amdd.getId());
                info.setEnabled(true);
                info.setVersions(getSchemaVersions(amdd.getId()));
                response.resume(Response.status(Response.Status.CREATED).entity(info).build());
            }
        });
    }
}
 
Example 11
public static void load(AudioPlayerManager manager, Lavalink<?> lavalink, String query,
                        AudioLoadResultHandler handler) {
    Iterator<LavalinkSocket> sockets = lavalink.getNodes().iterator();
    if (!sockets.hasNext()) {
        manager.loadItem(query, handler);
        return;
    }

    CompletionStage<Runnable> last = tryLoad(manager, sockets.next().getRemoteUri(), query, handler);
    while (sockets.hasNext()) {
        URI uri = sockets.next().getRemoteUri();
        //TODO: java 12 replace this with the line commented below
        var cf = new CompletableFuture<Runnable>();
        last.thenApply(CompletableFuture::completedStage)
                .exceptionally(e -> tryLoad(manager, uri, query, handler))
                .thenCompose(Function.identity())
                .thenAccept(cf::complete)
                .exceptionally(e -> {
                    cf.completeExceptionally(e);
                    return null;
                });
        last = cf;
        //last = last.exceptionallyCompose(e -> tryLoad(manager, uri, query, handler));
    }
    last.whenComplete((ok, oof) -> {
        if (oof != null) {
            handler.loadFailed(new FriendlyException("Failed to load", FriendlyException.Severity.SUSPICIOUS, oof));
        } else {
            ok.run();
        }
    });
}
 
Example 12
Source Project: besu   File: FutureUtils.java    License: Apache License 2.0 5 votes vote down vote up
/**
 * Propagates the result of one {@link CompletionStage} to a different {@link CompletableFuture}.
 *
 * <p>When <code>from</code> completes successfully, <code>to</code> will be completed
 * successfully with the same value. When <code>from</code> completes exceptionally, <code>to
 * </code> will be completed exceptionally with the same exception.
 *
 * @param from the CompletionStage to take results and exceptions from
 * @param to the CompletableFuture to propagate results and exceptions to
 * @param <T> the type of the success value
 */
public static <T> void propagateResult(
    final CompletionStage<T> from, final CompletableFuture<T> to) {
  from.whenComplete(
      (value, error) -> {
        if (error != null) {
          to.completeExceptionally(error);
        } else {
          to.complete(value);
        }
      });
}
 
Example 13
@Test
public void createFromFutureGoingToBeCompleted() {
    CompletableFuture<String> cf = new CompletableFuture<>();
    CompletionStage<Optional<String>> stage = ReactiveStreams.fromCompletionStageNullable(cf).findFirst().run();

    AtomicBoolean done = new AtomicBoolean();
    stage.whenComplete((res, err) -> {
        assertThat(err).isNull();
        assertThat(res).contains("Hello");
        done.set(true);
    });

    new Thread(() -> cf.complete("Hello")).start();
    await().untilAtomic(done, is(true));
}
 
Example 14
@Test
public void createFromFutureGoingToBeCompleted() {
    CompletableFuture<String> cf = new CompletableFuture<>();
    CompletionStage<Optional<String>> stage = ReactiveStreams.fromCompletionStage(cf).findFirst().run();

    AtomicBoolean done = new AtomicBoolean();
    stage.whenComplete((res, err) -> {
        assertThat(err).isNull();
        assertThat(res).contains("Hello");
        done.set(true);
    });

    new Thread(() -> cf.complete("Hello")).start();
    await().untilAtomic(done, is(true));
}
 
Example 15
@Test
public void createFromFutureGoingToBeFailed() {
    CompletableFuture<String> cf = new CompletableFuture<>();
    CompletionStage<Optional<String>> stage = ReactiveStreams.fromCompletionStage(cf).findFirst().run();

    AtomicBoolean done = new AtomicBoolean();
    stage.whenComplete((res, err) -> {
        assertThat(err).isNotNull().hasMessageContaining("Expected");
        assertThat(res).isNull();
        done.set(true);
    });

    new Thread(() -> cf.completeExceptionally(new Exception("Expected"))).start();
    await().untilAtomic(done, is(true));
}
 
Example 16
/**
 * Returns a future that is completed when the stage is completed and has the same value or exception
 * as the completed stage. It's supposed to be equivalent to calling 
 * {@link CompletionStage#toCompletableFuture()} but works with any CompletionStage
 * and doesn't throw {@link java.lang.UnsupportedOperationException}.
 * 
 * @param <U> The type of the future result
 * @param stage Stage to convert to a future
 * @return Future converted from stage
 */
public static <U> CompletableFuture<U> toCompletableFuture(CompletionStage<U> stage) {
    CompletableFuture<U> future = new CompletableFuture<>();
    stage.whenComplete((v, e) -> {
        if (e != null) {
            future.completeExceptionally(e);
        }
        else {
            future.complete(v);
        }
    });
    return future;
}
 
Example 17
protected static void test(TestContext context, CompletionStage<?> cs) {
	// this will be added to TestContext in the next vert.x release
	Async async = context.async();
	cs.whenComplete( (res, err) -> {
		if ( err != null ) {
			context.fail( err );
		}
		else {
			async.complete();
		}
	} );
}
 
Example 18
@Test
public void cancellationBeforeListen() throws InterruptedException {
    CompletionStage<String> stage = source.toCompletionStage();
    AtomicReference<Throwable> causeRef = new AtomicReference<>();
    CountDownLatch latch = new CountDownLatch(1);
    stage.toCompletableFuture().cancel(true);
    stage.whenComplete((s, t) -> {
        causeRef.set(t);
        latch.countDown();
    });
    assertTrue(latch.await(100, MILLISECONDS));
}
 
Example 19
Source Project: ditto   File: DittoService.java    License: Eclipse Public License 2.0 5 votes vote down vote up
private void startAkkaManagement(final ActorSystem actorSystem) {
    logger.info("Starting AkkaManagement ...");
    final AkkaManagement akkaManagement = AkkaManagement.get(actorSystem);
    final CompletionStage<Uri> startPromise = akkaManagement.start();
    startPromise.whenComplete((uri, throwable) -> {
        if (null != throwable) {
            logger.error("Error during start of AkkaManagement: <{}>!", throwable.getMessage(), throwable);
        } else {
            logger.info("Started AkkaManagement on URI <{}>.", uri);
        }
    });
}
 
Example 20
@Test
public void createFromFutureGoingToBeFailed() {
    CompletableFuture<String> cf = new CompletableFuture<>();
    CompletionStage<Optional<String>> stage = ReactiveStreams.fromCompletionStage(cf).findFirst().run();

    AtomicBoolean done = new AtomicBoolean();
    stage.whenComplete((res, err) -> {
        assertThat(err).isNotNull().hasMessageContaining("Expected");
        assertThat(res).isNull();
        done.set(true);
    });

    new Thread(() -> cf.completeExceptionally(new Exception("Expected"))).start();
    await().untilAtomic(done, is(true));
}