spring HttpMessageWriter 源码

spring HttpMessageWriter 代码

文件路径：/spring-web/src/main/java/org/springframework/http/codec/HttpMessageWriter.java

/*
 * Copyright 2002-2021 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.http.codec;

import java.util.Collections;
import java.util.List;
import java.util.Map;

import org.reactivestreams.Publisher;
import reactor.core.publisher.Mono;

import org.springframework.core.MethodParameter;
import org.springframework.core.ResolvableType;
import org.springframework.http.MediaType;
import org.springframework.http.ReactiveHttpOutputMessage;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.lang.Nullable;

/**
 * Strategy for encoding a stream of objects of type {@code <T>} and writing
 * the encoded stream of bytes to an {@link ReactiveHttpOutputMessage}.
 *
 * @author Rossen Stoyanchev
 * @author Arjen Poutsma
 * @author Sebastien Deleuze
 * @since 5.0
 * @param <T> the type of objects in the input stream
 */
public interface HttpMessageWriter<T> {

	/**
	 * Return the list of media types supported by this Writer. The list may not
	 * apply to every possible target element type and calls to this method should
	 * typically be guarded via {@link #canWrite(ResolvableType, MediaType)
	 * canWrite(elementType, null)}. The list may also exclude media types
	 * supported only for a specific element type. Alternatively, use
	 * {@link #getWritableMediaTypes(ResolvableType)} for a more precise list.
	 * @return the general list of supported media types
	 */
	List<MediaType> getWritableMediaTypes();

	/**
	 * Return the list of media types supported by this Writer for the given type
	 * of element. This list may differ from {@link #getWritableMediaTypes()}
	 * if the Writer doesn't support the element type, or if it supports it
	 * only for a subset of media types.
	 * @param elementType the type of element to encode
	 * @return the list of media types supported for the given class
	 * @since 5.3.4
	 */
	default List<MediaType> getWritableMediaTypes(ResolvableType elementType) {
		return (canWrite(elementType, null) ? getWritableMediaTypes() : Collections.emptyList());
	}

	/**
	 * Whether the given object type is supported by this writer.
	 * @param elementType the type of object to check
	 * @param mediaType the media type for the write (possibly {@code null})
	 * @return {@code true} if writable, {@code false} otherwise
	 */
	boolean canWrite(ResolvableType elementType, @Nullable MediaType mediaType);

	/**
	 * Write a given stream of object to the output message.
	 * @param inputStream the objects to write
	 * @param elementType the type of objects in the stream which must have been
	 * previously checked via {@link #canWrite(ResolvableType, MediaType)}
	 * @param mediaType the content type for the write (possibly {@code null} to
	 * indicate that the default content type of the writer must be used)
	 * @param message the message to write to
	 * @param hints additional information about how to encode and write
	 * @return indicates completion or error
	 */
	Mono<Void> write(Publisher<? extends T> inputStream, ResolvableType elementType,
			@Nullable MediaType mediaType, ReactiveHttpOutputMessage message, Map<String, Object> hints);

	/**
	 * Server-side only alternative to
	 * {@link #write(Publisher, ResolvableType, MediaType, ReactiveHttpOutputMessage, Map)}
	 * with additional context available.
	 * @param actualType the actual return type of the method that returned the
	 * value; for annotated controllers, the {@link MethodParameter} can be
	 * accessed via {@link ResolvableType#getSource()}.
	 * @param elementType the type of Objects in the input stream
	 * @param mediaType the content type to use (possibly {@code null} indicating
	 * the default content type of the writer should be used)
	 * @param request the current request
	 * @param response the current response
	 * @return a {@link Mono} that indicates completion of writing or error
	 */
	default Mono<Void> write(Publisher<? extends T> inputStream, ResolvableType actualType,
			ResolvableType elementType, @Nullable MediaType mediaType, ServerHttpRequest request,
			ServerHttpResponse response, Map<String, Object> hints) {

		return write(inputStream, elementType, mediaType, response, hints);
	}

}

相关信息

spring 源码目录

相关文章

spring ClientCodecConfigurer 源码

spring CodecConfigurer 源码

spring CodecConfigurerFactory 源码

spring CodecConfigurerRuntimeHints 源码

spring DecoderHttpMessageReader 源码

spring EncoderHttpMessageWriter 源码

spring FormHttpMessageReader 源码

spring FormHttpMessageWriter 源码

spring HttpMessageDecoder 源码

spring HttpMessageEncoder 源码