001/*
002 * Copyright 2002-2017 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.messaging.handler.invocation;
018
019import java.util.concurrent.CompletableFuture;
020import java.util.concurrent.CompletionStage;
021
022import org.springframework.core.MethodParameter;
023import org.springframework.lang.UsesJava8;
024import org.springframework.util.concurrent.CompletableToListenableFutureAdapter;
025import org.springframework.util.concurrent.ListenableFuture;
026
027/**
028 * Support for {@link CompletableFuture} (and as of 4.3.7 also {@link CompletionStage})
029 * as a return value type.
030 *
031 * @author Sebastien Deleuze
032 * @author Juergen Hoeller
033 * @since 4.2
034 */
035@UsesJava8
036public class CompletableFutureReturnValueHandler extends AbstractAsyncReturnValueHandler {
037
038        @Override
039        public boolean supportsReturnType(MethodParameter returnType) {
040                return CompletionStage.class.isAssignableFrom(returnType.getParameterType());
041        }
042
043        @Override
044        @SuppressWarnings("unchecked")
045        public ListenableFuture<?> toListenableFuture(Object returnValue, MethodParameter returnType) {
046                return new CompletableToListenableFutureAdapter<Object>((CompletionStage<Object>) returnValue);
047        }
048
049}