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.messaging.core; 018 019import org.springframework.lang.Nullable; 020import org.springframework.messaging.Message; 021import org.springframework.messaging.MessagingException; 022 023/** 024 * Operations for receiving messages from a destination. 025 * 026 * @author Mark Fisher 027 * @author Rossen Stoyanchev 028 * @since 4.0 029 * @param <D> the type of destination 030 * @see GenericMessagingTemplate 031 */ 032public interface MessageReceivingOperations<D> { 033 034 /** 035 * Receive a message from a default destination. 036 * @return the received message, possibly {@code null} if the message could not 037 * be received, for example due to a timeout 038 */ 039 @Nullable 040 Message<?> receive() throws MessagingException; 041 042 /** 043 * Receive a message from the given destination. 044 * @param destination the target destination 045 * @return the received message, possibly {@code null} if the message could not 046 * be received, for example due to a timeout 047 */ 048 @Nullable 049 Message<?> receive(D destination) throws MessagingException; 050 051 /** 052 * Receive a message from a default destination and convert its payload to the 053 * specified target class. 054 * @param targetClass the target class to convert the payload to 055 * @return the converted payload of the reply message, possibly {@code null} if 056 * the message could not be received, for example due to a timeout 057 */ 058 @Nullable 059 <T> T receiveAndConvert(Class<T> targetClass) throws MessagingException; 060 061 /** 062 * Receive a message from the given destination and convert its payload to the 063 * specified target class. 064 * @param destination the target destination 065 * @param targetClass the target class to convert the payload to 066 * @return the converted payload of the reply message, possibly {@code null} if 067 * the message could not be received, for example due to a timeout 068 */ 069 @Nullable 070 <T> T receiveAndConvert(D destination, Class<T> targetClass) throws MessagingException; 071 072}