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.client;
018
019import java.io.IOException;
020import java.lang.reflect.Type;
021
022import org.springframework.http.client.ClientHttpRequest;
023
024/**
025 * Callback interface for code that operates on a {@link ClientHttpRequest}.
026 * Allows manipulating the request headers, and write to the request body.
027 *
028 * <p>Used internally by the {@link RestTemplate}, but also useful for
029 * application code. There several available factory methods:
030 * <ul>
031 * <li>{@link RestTemplate#acceptHeaderRequestCallback(Class)}
032 * <li>{@link RestTemplate#httpEntityCallback(Object)}
033 * <li>{@link RestTemplate#httpEntityCallback(Object, Type)}
034 * </ul>
035 *
036 * @author Arjen Poutsma
037 * @see RestTemplate#execute
038 * @since 3.0
039 */
040@FunctionalInterface
041public interface RequestCallback {
042
043        /**
044         * Gets called by {@link RestTemplate#execute} with an opened {@code ClientHttpRequest}.
045         * Does not need to care about closing the request or about handling errors:
046         * this will all be handled by the {@code RestTemplate}.
047         * @param request the active HTTP request
048         * @throws IOException in case of I/O errors
049         */
050        void doWithRequest(ClientHttpRequest request) throws IOException;
051
052}