Question

我在heroku上运行了一个spring boot应用程序。我利用websocket在特定用户的客户端和服务器之间发送消息。我使用Spring Boot的SimpMessagingTemplate.convertAndSendToUser来发送和接收消息，当用户需要从服务器获取消息时，该方法很好用。我使用Heroku会话亲缘关系，这意味着即使我扩大了会话数量，用户和websocket仍然共享同一会话。

我需要一个用户向另一个用户发送消息时出现问题。如果两个用户都共享会话，则效果很好，但是如果消息不会通过，则效果不佳。

是否可以使用SimpMessagingTemple在不同的会话中从一个用户向另一个用户发送消息？还是我需要使用消息代理，例如Redis。

我当时正在考虑使用StringRedisTemplate实现发送消息的方法，但是不确定如何向特定用户发送消息。

    private SimpMessagingTemplate messagingTemplate;
    @Autowired
    public MessageController(SimpMessagingTemplate messagingTemplate) {
        this.messagingTemplate = messagingTemplate;
    }

    @MessageMapping("/secured/user-in")
    public void sendToDevice(Message msg, @AuthenticationPrincipal User principal) throws Exception {

        if (msg.getTo() != null) {
        String email = msg.getTo();
        Message out = new Message();
        out.setMsg(msg.getMsg());
        out.setFrom(msg.getFrom());
        out.setTo(msg.getTo());
        out.setSentTime(new Date());
        out.setStatus(msg.getStatus());
        messagingTemplate.convertAndSendToUser(email, "/secured/topic", out);
        }       

    }

JS

function connect() {
    var socket = new SockJS('/secured/user-in');
    ST.stompClient = Stomp.over(socket);
    var headers = {};
    headers[ST.getHeader()] = ST.getToken();

    ST.getStompClient().connect(headers, function (frame) {
        retries = 1;
        console.log('Connected: ' + frame);
        ST.getStompClient().subscribe('/user/secured/topic', function (event){

            var msg = JSON.parse(event.body);
            showMessage(msg.msg); 

        });

    }); 

}

更新1

我想我可以像here一样做类似的事情：

    SimpMessageHeaderAccessor headerAccessor = SimpMessageHeaderAccessor
.create(SimpMessageType.MESSAGE);
    headerAccessor.setSessionId(sessionId);
    headerAccessor.setLeaveMutable(true);

    messagingTemplate.convertAndSendToUser(sessionId,"/queue/something", payload, 
    headerAccessor.getMessageHeaders());

但是如何获取另一个用户的会话ID，我正在使用Redis存储会话信息：@EnableRedisHttpSession

Answer 1

我的术语有点混乱，我试图通过另一个dyno而不是会话将消息发送给另一个用户。

最终使用redis sub / pub。

因此，当控制器接收到消息时，该消息将发布到redis，并且redis MessageListenerAdapter会调用convertAndSendToUser方法。

@MessageMapping("/secured/user-in")
public void sendToDevice(Message msg, @AuthenticationPrincipal User principal) throws Exception {
    publishMessageToRedis(msg);
}

private void publishMessageToRedis(Message message) throws JsonProcessingException {
    ObjectMapper objectMapper = new ObjectMapper();
    String messageString = objectMapper.writeValueAsString(message);
    stringRedisTemplate.convertAndSend("message", messageString);

}

redis配置

@Bean
RedisMessageListenerContainer container( MessageListenerAdapter chatMessageListenerAdapter) throws URISyntaxException {

    RedisMessageListenerContainer container = new RedisMessageListenerContainer();
    container.setConnectionFactory(connectionFactory());
    container.addMessageListener(chatMessageListenerAdapter,  new PatternTopic("message"));
    return container;
}

@Bean("chatMessageListenerAdapter")
MessageListenerAdapter chatMessageListenerAdapter(RedisReceiver redisReceiver) {
    return new MessageListenerAdapter(redisReceiver, "receiveChatMessage");
}

public class RedisReceiver {
    private static final Logger LOG = LogManager.getLogger(RedisReceiver.class);
    private final WebSocketMessageService webSocketMessageService;

    @Autowired
    public RedisReceiver(WebSocketMessageService webSocketMessageService) {
        this.webSocketMessageService = webSocketMessageService;
    }

    // Invoked when message is publish to "chat" channel
    public void receiveChatMessage(String messageStr) throws IOException {

        ObjectMapper objectMapper = new ObjectMapper();
        Message message = objectMapper.readValue(messageStr, Message.class);
        webSocketMessageService.sendChatMessage(message);

    }

}

@Service
public class WebSocketMessageService {

    private final SimpMessagingTemplate template;
    private static final Logger LOG = LogManager.getLogger(WebSocketMessageService.class);

    public WebSocketMessageService(SimpMessagingTemplate template) {

        this.template = template;
    }

    public void sendChatMessage(Message message) {
        template.convertAndSendToUser(message.getTo(), "/secured/topic", message);
    }

}

解决方案基于此git repository

通过测功机向用户发送Websocket消息

1 个答案: