org.springframework.util.concurrent.ListenableFuture Maven / Gradle / Ivy
/*
* Copyright 2002-2018 the original author or authors.
*
* 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
*
* https://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 org.springframework.util.concurrent;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.Future;
/**
* Extend {@link Future} with the capability to accept completion callbacks.
* If the future has completed when the callback is added, the callback is
* triggered immediately.
*
* Inspired by {@code com.google.common.util.concurrent.ListenableFuture}.
*
* @author Arjen Poutsma
* @author Sebastien Deleuze
* @author Juergen Hoeller
* @since 4.0
* @param the result type returned by this Future's {@code get} method
*/
public interface ListenableFuture extends Future {
/**
* Register the given {@code ListenableFutureCallback}.
* @param callback the callback to register
*/
void addCallback(ListenableFutureCallback callback);
/**
* Java 8 lambda-friendly alternative with success and failure callbacks.
* @param successCallback the success callback
* @param failureCallback the failure callback
* @since 4.1
*/
void addCallback(SuccessCallback successCallback, FailureCallback failureCallback);
/**
* Expose this {@link ListenableFuture} as a JDK {@link CompletableFuture}.
* @since 5.0
*/
default CompletableFuture completable() {
CompletableFuture completable = new DelegatingCompletableFuture<>(this);
addCallback(completable::complete, completable::completeExceptionally);
return completable;
}
}