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.web.servlet.mvc.method.annotation;
018
019import org.springframework.core.MethodParameter;
020import org.springframework.http.MediaType;
021import org.springframework.http.converter.HttpMessageConverter;
022import org.springframework.http.server.ServerHttpRequest;
023import org.springframework.http.server.ServerHttpResponse;
024
025/**
026 * Allows customizing the response after the execution of an {@code @ResponseBody}
027 * or a {@code ResponseEntity} controller method but before the body is written
028 * with an {@code HttpMessageConverter}.
029 *
030 * <p>Implementations may be registered directly with
031 * {@code RequestMappingHandlerAdapter} and {@code ExceptionHandlerExceptionResolver}
032 * or more likely annotated with {@code @ControllerAdvice} in which case they
033 * will be auto-detected by both.
034 *
035 * @author Rossen Stoyanchev
036 * @since 4.1
037 */
038public interface ResponseBodyAdvice<T> {
039
040        /**
041         * Whether this component supports the given controller method return type
042         * and the selected {@code HttpMessageConverter} type.
043         * @param returnType the return type
044         * @param converterType the selected converter type
045         * @return {@code true} if {@link #beforeBodyWrite} should be invoked;
046         * {@code false} otherwise
047         */
048        boolean supports(MethodParameter returnType, Class<? extends HttpMessageConverter<?>> converterType);
049
050        /**
051         * Invoked after an {@code HttpMessageConverter} is selected and just before
052         * its write method is invoked.
053         * @param body the body to be written
054         * @param returnType the return type of the controller method
055         * @param selectedContentType the content type selected through content negotiation
056         * @param selectedConverterType the converter type selected to write to the response
057         * @param request the current request
058         * @param response the current response
059         * @return the body that was passed in or a modified (possibly new) instance
060         */
061        T beforeBodyWrite(T body, MethodParameter returnType, MediaType selectedContentType,
062                        Class<? extends HttpMessageConverter<?>> selectedConverterType,
063                        ServerHttpRequest request, ServerHttpResponse response);
064
065}