001/* 002 * Copyright 2002-2015 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; 018 019import java.util.Map; 020 021import org.springframework.messaging.MessagingException; 022import org.springframework.messaging.core.MessagePostProcessor; 023import org.springframework.messaging.core.MessageSendingOperations; 024 025/** 026 * A specialization of {@link MessageSendingOperations} with methods for use with 027 * the Spring Framework support for Simple Messaging Protocols (like STOMP). 028 * 029 * <p>For more on user destinations see 030 * {@link org.springframework.messaging.simp.user.UserDestinationResolver 031 * UserDestinationResolver}. 032 * 033 * <p>Generally it is expected the user is the one authenticated with the 034 * WebSocket session (or by extension the user authenticated with the 035 * handshake request that started the session). However if the session is 036 * not authenticated, it is also possible to pass the session id (if known) 037 * in place of the user name. Keep in mind though that in that scenario, 038 * you must use one of the overloaded methods that accept headers making sure the 039 * {@link org.springframework.messaging.simp.SimpMessageHeaderAccessor#setSessionId 040 * sessionId} header has been set accordingly. 041 * 042 * @author Rossen Stoyanchev 043 * @since 4.0 044 */ 045public interface SimpMessageSendingOperations extends MessageSendingOperations<String> { 046 047 /** 048 * Send a message to the given user. 049 * @param user the user that should receive the message. 050 * @param destination the destination to send the message to. 051 * @param payload the payload to send 052 */ 053 void convertAndSendToUser(String user, String destination, Object payload) throws MessagingException; 054 055 /** 056 * Send a message to the given user. 057 * <p>By default headers are interpreted as native headers (e.g. STOMP) and 058 * are saved under a special key in the resulting Spring 059 * {@link org.springframework.messaging.Message Message}. In effect when the 060 * message leaves the application, the provided headers are included with it 061 * and delivered to the destination (e.g. the STOMP client or broker). 062 * <p>If the map already contains the key 063 * {@link org.springframework.messaging.support.NativeMessageHeaderAccessor#NATIVE_HEADERS "nativeHeaders"} 064 * or was prepared with 065 * {@link org.springframework.messaging.simp.SimpMessageHeaderAccessor SimpMessageHeaderAccessor} 066 * then the headers are used directly. A common expected case is providing a 067 * content type (to influence the message conversion) and native headers. 068 * This may be done as follows: 069 * <pre class="code"> 070 * SimpMessageHeaderAccessor accessor = SimpMessageHeaderAccessor.create(); 071 * accessor.setContentType(MimeTypeUtils.TEXT_PLAIN); 072 * accessor.setNativeHeader("foo", "bar"); 073 * accessor.setLeaveMutable(true); 074 * MessageHeaders headers = accessor.getMessageHeaders(); 075 * messagingTemplate.convertAndSendToUser(user, destination, payload, headers); 076 * </pre> 077 * <p><strong>Note:</strong> if the {@code MessageHeaders} are mutable as in 078 * the above example, implementations of this interface should take notice and 079 * update the headers in the same instance (rather than copy or re-create it) 080 * and then set it immutable before sending the final message. 081 * @param user the user that should receive the message (must not be {@code null}) 082 * @param destination the destination to send the message to (must not be {@code null}) 083 * @param payload the payload to send (may be {@code null}) 084 * @param headers the message headers (may be {@code null}) 085 */ 086 void convertAndSendToUser(String user, String destination, Object payload, Map<String, Object> headers) 087 throws MessagingException; 088 089 /** 090 * Send a message to the given user. 091 * @param user the user that should receive the message (must not be {@code null}) 092 * @param destination the destination to send the message to (must not be {@code null}) 093 * @param payload the payload to send (may be {@code null}) 094 * @param postProcessor a postProcessor to post-process or modify the created message 095 */ 096 void convertAndSendToUser(String user, String destination, Object payload, 097 MessagePostProcessor postProcessor) throws MessagingException; 098 099 /** 100 * Send a message to the given user. 101 * <p>See {@link #convertAndSend(Object, Object, java.util.Map)} for important 102 * notes regarding the input headers. 103 * @param user the user that should receive the message 104 * @param destination the destination to send the message to 105 * @param payload the payload to send 106 * @param headers the message headers 107 * @param postProcessor a postProcessor to post-process or modify the created message 108 */ 109 void convertAndSendToUser(String user, String destination, Object payload, Map<String, Object> headers, 110 MessagePostProcessor postProcessor) throws MessagingException; 111 112}