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.simp.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.core.annotation.AliasFor;
026
027/**
028 * Annotation that indicates that the return value of a message-handling method
029 * should be sent as a {@link org.springframework.messaging.Message} to the specified
030 * destination(s) prepended with <code>"/user/{username}"</code> where the user name
031 * is extracted from the headers of the input message being handled.
032 *
033 * <p>The annotation may also be placed at class-level in which case all methods
034 * in the class where the annotation applies will inherit it.
035
036 * @author Rossen Stoyanchev
037 * @author Sam Brannen
038 * @since 4.0
039 * @see org.springframework.messaging.simp.annotation.support.SendToMethodReturnValueHandler
040 * @see org.springframework.messaging.simp.user.UserDestinationMessageHandler
041 * @see org.springframework.messaging.simp.SimpMessageHeaderAccessor#getUser()
042 */
043@Target({ElementType.METHOD, ElementType.TYPE})
044@Retention(RetentionPolicy.RUNTIME)
045@Documented
046public @interface SendToUser {
047
048        /**
049         * Alias for {@link #destinations}.
050         * @see #destinations
051         */
052        @AliasFor("destinations")
053        String[] value() default {};
054
055        /**
056         * One or more destinations to send a message to.
057         * <p>If left unspecified, a default destination is selected based on the
058         * destination of the input message being handled.
059         * @since 4.2
060         * @see #value
061         * @see org.springframework.messaging.simp.annotation.support.SendToMethodReturnValueHandler
062         */
063        @AliasFor("value")
064        String[] destinations() default {};
065
066        /**
067         * Whether messages should be sent to all sessions associated with the user
068         * or only to the session of the input message being handled.
069         * <p>By default, this is set to {@code true} in which case messages are
070         * broadcast to all sessions.
071     */
072    boolean broadcast() default true;
073
074}