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.http.client;
018
019import java.io.IOException;
020
021import org.springframework.http.HttpRequest;
022import org.springframework.util.concurrent.ListenableFuture;
023
024/**
025 * Intercepts client-side HTTP requests. Implementations of this interface can be
026 * {@linkplain org.springframework.web.client.AsyncRestTemplate#setInterceptors registered}
027 * with the {@link org.springframework.web.client.AsyncRestTemplate} as to modify
028 * the outgoing {@link HttpRequest} and/or register to modify the incoming
029 * {@link ClientHttpResponse} with help of a
030 * {@link org.springframework.util.concurrent.ListenableFutureAdapter}.
031 *
032 * <p>The main entry point for interceptors is {@link #intercept}.
033 *
034 * @author Jakub Narloch
035 * @author Rossen Stoyanchev
036 * @since 4.3
037 * @see org.springframework.web.client.AsyncRestTemplate
038 * @see org.springframework.http.client.support.InterceptingAsyncHttpAccessor
039 * @deprecated as of Spring 5.0, in favor of
040 * {@link org.springframework.web.reactive.function.client.ExchangeFilterFunction}
041 */
042@Deprecated
043public interface AsyncClientHttpRequestInterceptor {
044
045        /**
046         * Intercept the given request, and return a response future. The given
047         * {@link AsyncClientHttpRequestExecution} allows the interceptor to pass on
048         * the request to the next entity in the chain.
049         * <p>An implementation might follow this pattern:
050         * <ol>
051         * <li>Examine the {@linkplain HttpRequest request} and body</li>
052         * <li>Optionally {@linkplain org.springframework.http.client.support.HttpRequestWrapper
053         * wrap} the request to filter HTTP attributes.</li>
054         * <li>Optionally modify the body of the request.</li>
055         * <li>One of the following:
056         * <ul>
057         * <li>execute the request through {@link ClientHttpRequestExecution}</li>
058         * <li>don't execute the request to block the execution altogether</li>
059         * </ul>
060         * <li>Optionally adapt the response to filter HTTP attributes with the help of
061         * {@link org.springframework.util.concurrent.ListenableFutureAdapter
062         * ListenableFutureAdapter}.</li>
063         * </ol>
064         * @param request the request, containing method, URI, and headers
065         * @param body the body of the request
066         * @param execution the request execution
067         * @return the response future
068         * @throws IOException in case of I/O errors
069         */
070        ListenableFuture<ClientHttpResponse> intercept(HttpRequest request, byte[] body,
071                        AsyncClientHttpRequestExecution execution) throws IOException;
072
073}