001/* 002 * Copyright 2002-2016 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.handler.annotation; 018 019import java.lang.annotation.Documented; 020import java.lang.annotation.ElementType; 021import java.lang.annotation.Retention; 022import java.lang.annotation.RetentionPolicy; 023import java.lang.annotation.Target; 024 025import org.springframework.messaging.Message; 026 027/** 028 * Annotation that indicates a method's return value should be converted to 029 * a {@link Message} if necessary and sent to the specified destination. 030 * 031 * <p>In a typical request/reply scenario, the incoming {@link Message} may 032 * convey the destination to use for the reply. In that case, that destination 033 * should take precedence. 034 * 035 * <p>The annotation may also be placed at class-level if the provider supports 036 * it to indicate that all related methods should use this destination if none 037 * is specified otherwise. 038 * 039 * @author Rossen Stoyanchev 040 * @author Stephane Nicoll 041 * @since 4.0 042 */ 043@Target({ElementType.METHOD, ElementType.TYPE}) 044@Retention(RetentionPolicy.RUNTIME) 045@Documented 046public @interface SendTo { 047 048 /** 049 * The destination for a message created from the return value of a method. 050 */ 051 String[] value() default {}; 052 053}