001/*
002 * Copyright 2002-2019 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
025/**
026 * Annotation that indicates a method parameter should be bound to a template variable
027 * in a destination template string. Supported on message handling methods such as
028 * {@link MessageMapping @MessageMapping}.
029 *
030 * <p>A {@code @DestinationVariable} template variable is always required.
031 *
032 * @author Brian Clozel
033 * @author Rossen Stoyanchev
034 * @since 4.0
035 * @see org.springframework.messaging.handler.annotation.MessageMapping
036 * @see org.springframework.messaging.simp.annotation.support.SimpAnnotationMethodMessageHandler
037 */
038@Target(ElementType.PARAMETER)
039@Retention(RetentionPolicy.RUNTIME)
040@Documented
041public @interface DestinationVariable {
042
043        /**
044         * The name of the destination template variable to bind to.
045         */
046        String value() default "";
047
048}