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.http.codec; 018 019import java.util.List; 020import java.util.Map; 021 022import org.springframework.core.ResolvableType; 023import org.springframework.core.codec.Encoder; 024import org.springframework.core.codec.Hints; 025import org.springframework.http.MediaType; 026import org.springframework.http.server.reactive.ServerHttpRequest; 027import org.springframework.http.server.reactive.ServerHttpResponse; 028import org.springframework.lang.Nullable; 029 030/** 031 * Extension of {@code Encoder} exposing extra methods relevant in the context 032 * of HTTP request or response body encoding. 033 * 034 * @author Rossen Stoyanchev 035 * @since 5.0 036 * @param <T> the type of elements in the input stream 037 */ 038public interface HttpMessageEncoder<T> extends Encoder<T> { 039 040 /** 041 * Return "streaming" media types for which flushing should be performed 042 * automatically vs at the end of the input stream. 043 */ 044 List<MediaType> getStreamingMediaTypes(); 045 046 /** 047 * Get decoding hints based on the server request or annotations on the 048 * target controller method parameter. 049 * @param actualType the actual source type to encode, possibly a reactive 050 * wrapper and sourced from {@link org.springframework.core.MethodParameter}, 051 * i.e. providing access to method annotations. 052 * @param elementType the element type within {@code Flux/Mono} that we're 053 * trying to encode. 054 * @param request the current request 055 * @param response the current response 056 * @return a Map with hints, possibly empty 057 */ 058 default Map<String, Object> getEncodeHints(ResolvableType actualType, ResolvableType elementType, 059 @Nullable MediaType mediaType, ServerHttpRequest request, ServerHttpResponse response) { 060 061 return Hints.none(); 062 } 063 064}