001/* 002 * Copyright 2002-2018 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * https://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.util.concurrent; 018 019import java.util.concurrent.CompletableFuture; 020import java.util.concurrent.CompletionStage; 021import java.util.concurrent.ExecutionException; 022import java.util.concurrent.TimeUnit; 023import java.util.concurrent.TimeoutException; 024 025/** 026 * Adapts a {@link CompletableFuture} or {@link CompletionStage} into a 027 * Spring {@link ListenableFuture}. 028 * 029 * @author Sebastien Deleuze 030 * @author Juergen Hoeller 031 * @since 4.2 032 * @param <T> the result type returned by this Future's {@code get} method 033 */ 034public class CompletableToListenableFutureAdapter<T> implements ListenableFuture<T> { 035 036 private final CompletableFuture<T> completableFuture; 037 038 private final ListenableFutureCallbackRegistry<T> callbacks = new ListenableFutureCallbackRegistry<>(); 039 040 041 /** 042 * Create a new adapter for the given {@link CompletionStage}. 043 * @since 4.3.7 044 */ 045 public CompletableToListenableFutureAdapter(CompletionStage<T> completionStage) { 046 this(completionStage.toCompletableFuture()); 047 } 048 049 /** 050 * Create a new adapter for the given {@link CompletableFuture}. 051 */ 052 public CompletableToListenableFutureAdapter(CompletableFuture<T> completableFuture) { 053 this.completableFuture = completableFuture; 054 this.completableFuture.whenComplete((result, ex) -> { 055 if (ex != null) { 056 this.callbacks.failure(ex); 057 } 058 else { 059 this.callbacks.success(result); 060 } 061 }); 062 } 063 064 065 @Override 066 public void addCallback(ListenableFutureCallback<? super T> callback) { 067 this.callbacks.addCallback(callback); 068 } 069 070 @Override 071 public void addCallback(SuccessCallback<? super T> successCallback, FailureCallback failureCallback) { 072 this.callbacks.addSuccessCallback(successCallback); 073 this.callbacks.addFailureCallback(failureCallback); 074 } 075 076 @Override 077 public CompletableFuture<T> completable() { 078 return this.completableFuture; 079 } 080 081 082 @Override 083 public boolean cancel(boolean mayInterruptIfRunning) { 084 return this.completableFuture.cancel(mayInterruptIfRunning); 085 } 086 087 @Override 088 public boolean isCancelled() { 089 return this.completableFuture.isCancelled(); 090 } 091 092 @Override 093 public boolean isDone() { 094 return this.completableFuture.isDone(); 095 } 096 097 @Override 098 public T get() throws InterruptedException, ExecutionException { 099 return this.completableFuture.get(); 100 } 101 102 @Override 103 public T get(long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException { 104 return this.completableFuture.get(timeout, unit); 105 } 106 107}