Java Code Examples for reactor.core.publisher.Mono#create()

@Override
public Mono<Task> getTask(String taskId) {
    logger.debug("Getting Task information about taskId {}", taskId);
    return Mono.create(sink -> attachCallerId(jobManagementService, CLIENT_ID)
            .findTask(TaskId.newBuilder().setId(taskId).build(), new StreamObserver<Task>() {
                @Override
                public void onNext(Task task) {
                    sink.success(task);
                }

                @Override
                public void onError(Throwable t) {
                    logger.error("Error fetching task information for task ID = {}", taskId);
                    apiErrors.incrementAndGet();
                    sink.error(t);
                }

                @Override
                public void onCompleted() {

                }
            }));
}
 

@Override
public Mono<Boolean> send(TcpMessage message) {
    return Mono.<Boolean>create((sink) -> {
        if (socket == null) {
            sink.error(new SocketException("socket closed"));
            return;
        }
        socket.write(Buffer.buffer(message.getPayload()), r -> {
            keepAlive();
            if (r.succeeded()) {
                sink.success(true);
            } else {
                sink.error(r.cause());
            }
        });
    });
}
 

@Override
public void stop() throws WebServerException {
    if (server == null) {
        return;
    }

    Mono<Void> future = Mono.create(sink -> server.close(result -> {
        if (result.succeeded()) {
            sink.success();
        } else {
            sink.error(result.cause());
        }
    }));

    future
        .doOnTerminate(() -> server = null)
        .block(Duration.ofSeconds(5));
}
 

public Mono<T> submit(Mono<T> action) {
    Preconditions.checkState(!shutdownFlag, "ReactorQueue has been shutdown");
    Preconditions.checkNotNull(action);

    StackTraceElement[] stackTrace = Thread.currentThread().getStackTrace();

    return Mono.create(sink -> {
        metrics.onSubmit();

        ActionHandler actionHandler = new ActionHandler(action, sink, stackTrace);
        if (!actionHandlers.offer(actionHandler)) {
            metrics.onQueueFull();
            sink.error(actionHandler.newException(new IllegalStateException("Queue is full")));
            return;
        }
        metrics.setQueueSize(actionHandlers.size());

        if (shutdownFlag) {
            actionHandler.terminate();
        } else {
            worker.schedule(this::drain);
        }
    });
}
 

@Override
public Mono<Void> writeWith(Publisher<? extends DataBuffer> chunks) {
    Mono<Void> writeCompletion = Mono.create(sink -> {
        logger.debug("Subscribing to body publisher");
        Subscriber<DataBuffer> subscriber = new WriteStreamSubscriber.Builder<HttpClientRequest, DataBuffer>()
            .writeStream(delegate)
            .endHook(sink)
            .nextHandler((stream, value) -> stream.write(bufferConverter.toBuffer(value)))
            .build();
        chunks.subscribe(subscriber);
    });

    Mono<Void> endCompletion = Mono.create(sink -> {
        logger.debug("Completing request after writing");
        delegate.end();
        sink.success();
    });

    return doCommit(() -> writeCompletion.then(endCompletion));
}
 

@Override
public Mono<Boolean> send(EncodedMessage message) {
    return Mono.create(sink -> {
        if (!(message instanceof MqttMessage)) {
            sink.error(new UnsupportedOperationException("unsupported message type:" + message.getClass()));
            return;
        }
        MqttMessage mqtt = ((MqttMessage) message);

        client.publish(mqtt.getTopic()
                , Buffer.buffer(mqtt.getPayload())
                , MqttQoS.valueOf(mqtt.getQosLevel())
                , mqtt.isDup()
                , mqtt.isRetain(), result -> {
                    if (result.succeeded()) {
                        sink.success(true);
                    } else {
                        sink.error(result.cause());
                    }
                });

    });
}
 

@Override
public <X> Mono fromCompletionStage(CompletionStage<X> cs) {
    return Mono.create(sink -> cs.whenComplete((X v, Throwable e) -> {
        if (e != null) {
            sink.error(e instanceof CompletionException ? e.getCause() : e);
        } else if (v != null) {
            sink.success(v);
        } else {
            sink.success();
        }
    }));
}
 

public Mono<Connection> createConnection(Origin origin, ConnectionSettings connectionSettings, SslContext sslContext) {
    return Mono.create(sink -> {
        ChannelFuture channelFuture = openConnection(origin, connectionSettings);

        channelFuture.addListener(future -> {
            if (future.isSuccess()) {
                sink.success(new NettyConnection(origin, channelFuture.channel(), httpRequestOperationFactory,
                        httpConfig, sslContext, sendSni, sniHost));
            } else {
                sink.error(new OriginUnreachableException(origin, future.cause()));
            }
        });
    });
}
 

@Override
public final Mono<? extends Connection> acquire(
		TransportConfig config,
		ConnectionObserver connectionObserver,
		@Nullable Supplier<? extends SocketAddress> remote,
		@Nullable AddressResolverGroup<?> resolverGroup) {
	Objects.requireNonNull(remote, "remoteAddress");
	Objects.requireNonNull(resolverGroup, "resolverGroup");
	return Mono.create(sink -> {
		SocketAddress remoteAddress = Objects.requireNonNull(remote.get(), "Remote Address supplier returned null");
		PoolKey holder = new PoolKey(remoteAddress, config.channelHash());
		PoolFactory<T> poolFactory = poolFactory(remoteAddress);
		InstrumentedPool<T> pool = channelPools.computeIfAbsent(holder, poolKey -> {
			if (log.isDebugEnabled()) {
				log.debug("Creating a new [{}] client pool [{}] for [{}]", name, poolFactory, remoteAddress);
			}

			InstrumentedPool<T> newPool = createPool(config, poolFactory, remoteAddress, resolverGroup);

			if (poolFactory.metricsEnabled || config.metricsRecorder() != null) {
				PooledConnectionProviderMetrics.registerMetrics(name,
						poolKey.hashCode() + "",
						Metrics.formatSocketAddress(remoteAddress),
						newPool.metrics());
			}
			return newPool;
		});

		pool.acquire(Duration.ofMillis(poolFactory.pendingAcquireTimeout))
		    .subscribe(createDisposableAcquire(connectionObserver, config.channelOperationsProvider(),
		            poolFactory.pendingAcquireTimeout, pool, sink));
	});
}
 

@Override
protected Mono<Void> writeWithInternal(Publisher<? extends DataBuffer> chunks) {
    return Mono.create(sink -> {
        logger.debug("Subscribing to body publisher");
        Subscriber<DataBuffer> subscriber = new WriteStreamSubscriber.Builder<HttpServerResponse, DataBuffer>()
            .writeStream(delegate)
            .endHook(sink)
            .nextHandler((stream, value) -> stream.write(bufferConverter.toBuffer(value)))
            .build();
        chunks.subscribe(subscriber);
    });
}
 

public <T> Mono<T> run(Mono<T> toRun, Function<Throwable, Mono<T>> fallback) {
	HystrixObservableCommand<T> command = createCommand(toRun, fallback);

	return Mono.create(s -> {
		Subscription sub = command.toObservable().subscribe(s::success, s::error, s::success);
		s.onCancel(sub::unsubscribe);
	});
}
 

public Mono<Long> deleteCity(Long id) {

        // 缓存存在，删除缓存
        String key = "city_" + id;
        boolean hasKey = redisTemplate.hasKey(key);
        if (hasKey) {
            redisTemplate.delete(key);

            LOGGER.info("CityHandler.deleteCity() : 从缓存中删除城市 ID >> " + id);
        }

        cityRepository.deleteById(id);
        return Mono.create(cityMonoSink -> cityMonoSink.success(id));
    }
 

/**
 * Binds the {@link ServerTransport} and returns a {@link Mono} of {@link DisposableServer}. If
 * {@link Mono} is cancelled, the underlying binding will be aborted. Once the {@link
 * DisposableServer} has been emitted and is not necessary anymore, disposing the main server
 * loop must be done by the user via {@link DisposableServer#dispose()}.
 *
 * @return a {@link Mono} of {@link DisposableServer}
 */
public Mono<? extends DisposableServer> bind() {
	CONF config = configuration();
	Objects.requireNonNull(config.bindAddress(), "bindAddress");

	Mono<? extends DisposableServer> mono =  Mono.create(sink -> {
		SocketAddress local = Objects.requireNonNull(config.bindAddress().get(), "Bind Address supplier returned null");
		if (local instanceof InetSocketAddress) {
			InetSocketAddress localInet = (InetSocketAddress) local;

			if (localInet.isUnresolved()) {
				local = AddressUtils.createResolved(localInet.getHostName(), localInet.getPort());
			}
		}

		boolean isDomainSocket = false;
		DisposableBind disposableServer;
		if (local instanceof DomainSocketAddress) {
			isDomainSocket = true;
			disposableServer = new UdsDisposableBind(sink, config, local);
		}
		else {
			disposableServer = new InetDisposableBind(sink, config, local);
		}

		ConnectionObserver childObs =
				new ChildObserver(config.defaultChildObserver().then(config.childObserver()));
		Acceptor acceptor = new Acceptor(config.childEventLoopGroup(), config.channelInitializer(childObs, null, true),
				config.childOptions, config.childAttrs, isDomainSocket);
		TransportConnector.bind(config, new AcceptorInitializer(acceptor), local, isDomainSocket)
		                  .subscribe(disposableServer);
	});

	if (config.doOnBind() != null) {
		mono = mono.doOnSubscribe(s -> config.doOnBind().accept(config));
	}
	return mono;
}
 

public Mono<Long> save(City city) {
    return Mono.create(cityMonoSink -> cityMonoSink.success(cityRepository.save(city)));
}
 

public Mono<Long> deleteCity(Long id) {
    cityRepository.deleteById(id);
    return Mono.create(cityMonoSink -> cityMonoSink.success(id));
}
 

@Override
public Mono<Connection> createConnection(Origin origin, ConnectionSettings connectionPoolConfiguration) {
    return Mono.create(sink -> {
        sink.success(new StubConnection(origin));
    });
}
 

@RequestMapping(method = RequestMethod.POST)
public Mono<Long> createCity(@RequestBody City city) {
    return Mono.create(cityMonoSink -> cityMonoSink.success(cityService.saveCity(city)));
}
 

@RequestMapping(value = "/{id}", method = RequestMethod.GET)
public Mono<City> findOneCity(@PathVariable("id") Long id) {
    return Mono.create(cityMonoSink -> cityMonoSink.success(cityService.findCityById(id)));
}
 

@Override
protected Mono<Object> afterMono(Method method, Mono<Object> result, Long aLong) {
    long methodExitTime = clock.wallTime();

    return Mono.create(sink -> {
        long subscriptionTime = clock.wallTime();

        registry.counter(
                RESULT_SUBSCRIPTION_COUNT_METRIC_NAME,
                tags(
                        "method", method.getName(),
                        "subscriptionStage", "subscribed"
                )
        ).increment();
        reportSubscriptionExecutionTime(method, methodExitTime, subscriptionTime);

        AtomicBoolean emittedValue = new AtomicBoolean();
        Disposable subscription = result
                .doOnCancel(() -> {
                    registry.counter(
                            RESULT_SUBSCRIPTION_COUNT_METRIC_NAME,
                            tags(
                                    "method", method.getName(),
                                    "subscriptionStage", "unsubscribed"
                            )
                    ).increment();
                }).subscribe(
                        next -> {
                            emittedValue.set(true);
                            registry.counter(
                                    RESULT_SUBSCRIPTION_COUNT_METRIC_NAME,
                                    tags(
                                            "method", method.getName(),
                                            "subscriptionStage", "onSuccess",
                                            "monoWithValue", "true"
                                    )
                            ).increment();
                            reportExecutionTime(method, subscriptionTime, TAG_STATUS_SUCCESS, TAG_CALL_STAGE_ON_MONO_SUCCESS);

                            sink.success(next);
                        },
                        error -> {
                            registry.counter(
                                    RESULT_SUBSCRIPTION_COUNT_METRIC_NAME,
                                    tags(
                                            "method", method.getName(),
                                            "subscriptionStage", "onError",
                                            "exception", getExceptionName(error)
                                    )
                            ).increment();
                            reportExecutionTime(method, subscriptionTime, TAG_STATUS_ERROR, TAG_CALL_STAGE_ON_MONO_SUCCESS);

                            sink.error(error);
                        },
                        () -> {
                            if (!emittedValue.get()) {
                                registry.counter(
                                        RESULT_SUBSCRIPTION_COUNT_METRIC_NAME,
                                        tags(
                                                "method", method.getName(),
                                                "subscriptionStage", "onSuccess",
                                                "monoWithValue", "false"
                                        )
                                ).increment();
                                reportExecutionTime(method, subscriptionTime, TAG_STATUS_SUCCESS, TAG_CALL_STAGE_ON_MONO_SUCCESS);

                                sink.success();
                            }
                        }
                );

        sink.onCancel(subscription);
    });
}
 

@RequestMapping(method = RequestMethod.PUT)
public Mono<Long> modifyCity(@RequestBody City city) {
    return Mono.create(cityMonoSink -> cityMonoSink.success(cityService.updateCity(city)));
}