Spring websocket：如何在 ChannelInterceptorAdapter 中轻松地将 Message<?> 的有效负载转换为 POJO

Question

我有一个 Spring 使用 websocket 的应用程序

我可以进行连接和发送消息等

@Controller是：

    @MessageMapping("/ws/notification")
    @SendTo("/topic/springframework.topic.websocket.reply")
    public NotificationReply handleNotification(Notification notification) {
     ...
    }

它工作正常。观察参数类型，Notification，是自定义对象

现在因为审计目的我有以下内容：

@Component
public class MessageChannelInterceptorAdapter extends ChannelInterceptorAdapter {

    @Override
    public void postSend(Message<?> message, MessageChannel channel, boolean sent) {

        StompHeaderAccessor stompHeaderAccessor = StompHeaderAccessor.wrap(message);

           ....

        switch(stompHeaderAccessor.getCommand()) {
            case CONNECT:
                logger.info("postSend ...");
                logger.info("STOMP Connect");
                break;
            ...
            case SEND:
                logger.info("postSend ...");
                logger.info("STOMP Send");
                printDetails(message, stompHeaderAccessor);
                break;

        ...
    } 


    private void printDetails(Message<?> message, StompHeaderAccessor stompHeaderAccessor) {
        logger.info("   {}", message.toString());
        logger.info("       Payload: {}", message.getPayload());
        logger.info("       Payload (String): {}", message.getPayload().toString());
        logger.info("           Payload (Class): {}", message.getPayload().getClass());

        if(stompHeaderAccessor.getDestination()!=null && stompHeaderAccessor.getDestination().equals("/app/ws/notification")) {
            logger.info("Aprrrr");
            Notification notification = (Notification) message.getPayload();
            logger.info("{}", notification);
        }

我得到：

ERROR o.s.w.s.m.StompSubProtocolHandler - 
Failed to send client message to application via MessageChannel in session 555qe12a. 
Sending STOMP ERROR to client. 
org.springframework.messaging.MessageDeliveryException: 
Failed to send message to ExecutorSubscribableChannel[clientInboundChannel]; 
nested exception is java.lang.ClassCastException: 
[B cannot be cast to com.manuel.jordan.websocket.message.Notification

我明白 [B 是 byte[]。

因此存在一种使用当前 Spring Framework API 将 Message<?> 有效载荷转换为特定 POJO 的简单方法？

记得在 class 中应用它是从 ChannelInterceptorAdapter

延伸出来的

Answer 1

AbstractMessageBrokerConfiguration 提供了这个 bean：

@Bean
public CompositeMessageConverter brokerMessageConverter() {

您需要将此 bean 注入您的 MessageChannelInterceptorAdapter 并调用其 fromMessage(Message<?> message, Class<?> targetClass):

Notification notification = (Notification) this.messageConverter.fromMessage(message, Notification.class);

Spring websocket：如何在 ChannelInterceptorAdapter 中轻松地将 Message<?> 的有效负载转换为 POJO

Spring websocket: how convert easily the Message<?>'s payload to POJO in ChannelInterceptorAdapter

spring

spring-websocket