/*
* 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 java.util.
Objects;
import java.util.function.
Supplier;
import reactor.core.
CoreSubscriber;
/**
* Defers the creation of the actual Publisher the Subscriber will be subscribed to.
*
* @param <T> the value type
*
* @see <a href="https://github.com/reactor/reactive-streams-commons">Reactive-Streams-Commons</a>
*/
final class
MonoDefer<T> extends
Mono<T> implements
SourceProducer<T> {
final
Supplier<? extends
Mono<? extends T>>
supplier;
MonoDefer(
Supplier<? extends
Mono<? extends T>>
supplier) {
this.
supplier =
Objects.
requireNonNull(
supplier, "supplier");
}
@
SuppressWarnings("unchecked")
public void
subscribe(
CoreSubscriber<? super T>
actual) {
Mono<? extends T>
p;
try {
p =
Objects.
requireNonNull(
supplier.
get(),
"The Mono returned by the supplier is null");
}
catch (
Throwable e) {
Operators.
error(
actual,
Operators.
onOperatorError(
e,
actual.
currentContext()));
return;
}
p.
subscribe(
actual);
}
@
Override
public
Object scanUnsafe(
Attr key) {
return null; //no particular key to be represented, still useful in hooks
}
}