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}