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.web.reactive.function.client;
018
019import reactor.core.publisher.Mono;
020
021/**
022 * Represents a function that exchanges a {@linkplain ClientRequest request} for a (delayed)
023 * {@linkplain ClientResponse}. Can be used as an alternative to {@link WebClient}.
024 *
025 * <p>For example:
026 * <pre class="code">
027 * ExchangeFunction exchangeFunction = ExchangeFunctions.create(new ReactorClientHttpConnector());
028 * ClientRequest&lt;Void&gt; request = ClientRequest.method(HttpMethod.GET, "https://example.com/resource").build();
029 *
030 * Mono&lt;String&gt; result = exchangeFunction
031 *     .exchange(request)
032 *     .then(response -> response.bodyToMono(String.class));
033 * </pre>
034 *
035 * @author Arjen Poutsma
036 * @since 5.0
037 */
038@FunctionalInterface
039public interface ExchangeFunction {
040
041        /**
042         * Exchange the given request for a response mono.
043         * @param request the request to exchange
044         * @return the delayed response
045         */
046        Mono<ClientResponse> exchange(ClientRequest request);
047
048        /**
049         * Filters this exchange function with the given {@code ExchangeFilterFunction}, resulting in a
050         * filtered {@code ExchangeFunction}.
051         * @param filter the filter to apply to this exchange
052         * @return the filtered exchange
053         * @see ExchangeFilterFunction#apply(ExchangeFunction)
054         */
055        default ExchangeFunction filter(ExchangeFilterFunction filter) {
056                return filter.apply(this);
057        }
058
059}