/*
 * Copyright (c) 2011-2017 Pivotal Software Inc, All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package reactor.core.publisher;

import reactor.core.CoreSubscriber;

Represents an never publisher which only calls onSubscribe.

This Publisher is effectively stateless and only a single instance exists. Use the instance() method to obtain a properly type-parametrized view of it.

See Also:
/** * Represents an never publisher which only calls onSubscribe. * <p> * This Publisher is effectively stateless and only a single instance exists. * Use the {@link #instance()} method to obtain a properly type-parametrized view of it. * * @see <a href="https://github.com/reactor/reactive-streams-commons">Reactive-Streams-Commons</a> */
final class MonoNever extends Mono<Object> implements SourceProducer<Object> { static final Mono<Object> INSTANCE = new MonoNever(); MonoNever() { // deliberately no op } @Override public void subscribe(CoreSubscriber<? super Object> actual) { actual.onSubscribe(Operators.emptySubscription()); } @Override public Object scanUnsafe(Attr key) { return null; //no particular key to be represented, still useful in hooks }
Returns a properly parametrized instance of this never Publisher.
Type parameters:
  • <T> – the value type
Returns:a properly parametrized instance of this never Publisher
/** * Returns a properly parametrized instance of this never Publisher. * * @param <T> the value type * @return a properly parametrized instance of this never Publisher */
@SuppressWarnings("unchecked") static <T> Mono<T> instance() { return (Mono<T>) INSTANCE; } }