001/* 002 * Copyright 2002-2015 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.messaging.converter; 018 019import org.springframework.messaging.Message; 020import org.springframework.messaging.MessageHeaders; 021 022/** 023 * A converter to turn the payload of a {@link Message} from serialized form to a typed 024 * Object and vice versa. The {@link MessageHeaders#CONTENT_TYPE} message header may be 025 * used to specify the media type of the message content. 026 * 027 * @author Mark Fisher 028 * @author Rossen Stoyanchev 029 * @since 4.0 030 */ 031public interface MessageConverter { 032 033 /** 034 * Convert the payload of a {@link Message} from a serialized form to a typed Object 035 * of the specified target class. The {@link MessageHeaders#CONTENT_TYPE} header 036 * should indicate the MIME type to convert from. 037 * <p>If the converter does not support the specified media type or cannot perform 038 * the conversion, it should return {@code null}. 039 * @param message the input message 040 * @param targetClass the target class for the conversion 041 * @return the result of the conversion, or {@code null} if the converter cannot 042 * perform the conversion 043 */ 044 Object fromMessage(Message<?> message, Class<?> targetClass); 045 046 /** 047 * Create a {@link Message} whose payload is the result of converting the given 048 * payload Object to serialized form. The optional {@link MessageHeaders} parameter 049 * may contain a {@link MessageHeaders#CONTENT_TYPE} header to specify the target 050 * media type for the conversion and it may contain additional headers to be added 051 * to the message. 052 * <p>If the converter does not support the specified media type or cannot perform 053 * the conversion, it should return {@code null}. 054 * @param payload the Object to convert 055 * @param headers optional headers for the message (may be {@code null}) 056 * @return the new message, or {@code null} if the converter does not support the 057 * Object type or the target media type 058 */ 059 Message<?> toMessage(Object payload, MessageHeaders headers); 060 061}