Spring Websocket STOMP：发送 RECEIPT 帧

Question

我有一个基于 Spring 及其 SimpleBroker 实现的 Websocket-stomp 服务器（不使用外部代理）。

我想启用 STOMP RECEIPT 消息。

如何配置我的代码以自动发送这些？

Answer 1

在 STOMP 协议的 Spring 集成测试中，我们有以下代码：

    //SimpleBrokerMessageHandler doesn't support RECEIPT frame, hence we emulate it this way
    @Bean
    public ApplicationListener<SessionSubscribeEvent> webSocketEventListener(
            final AbstractSubscribableChannel clientOutboundChannel) {
        return event -> {
            Message<byte[]> message = event.getMessage();
            StompHeaderAccessor stompHeaderAccessor = StompHeaderAccessor.wrap(message);
            if (stompHeaderAccessor.getReceipt() != null) {
                stompHeaderAccessor.setHeader("stompCommand", StompCommand.RECEIPT);
                stompHeaderAccessor.setReceiptId(stompHeaderAccessor.getReceipt());
                clientOutboundChannel.send(
                        MessageBuilder.createMessage(new byte[0], stompHeaderAccessor.getMessageHeaders()));
            }
        };
    }

https://github.com/spring-projects/spring-integration/blob/master/spring-integration-stomp/src/test/java/org/springframework/integration/stomp/inbound/StompInboundChannelAdapterWebSocketIntegrationTests.java

Answer 2

类似Artem Bilan帖子的解决方案，使用分离类实现监听器。

@Component
public class SubscribeListener implements ApplicationListener<SessionSubscribeEvent> {
    @Autowired
    AbstractSubscribableChannel clientOutboundChannel;

    @Override
    public void onApplicationEvent(SessionSubscribeEvent event) {
        Message<byte[]> message = event.getMessage();
        StompHeaderAccessor stompHeaderAccessor = StompHeaderAccessor.wrap(message);

        if (stompHeaderAccessor.getReceipt() != null) {
            StompHeaderAccessor receipt = StompHeaderAccessor.create(StompCommand.RECEIPT);
            receipt.setReceiptId(stompHeaderAccessor.getReceipt());    
            receipt.setSessionId(stompHeaderAccessor.getSessionId());
            clientOutboundChannel.send(MessageBuilder.createMessage(new byte[0], receipt.getMessageHeaders()));
        }
    }
}

Answer 3

Artem Bilan 提供的答案仅适用于 SUBSCRIBE 帧。这是另一种捕获带有收据标头的任何传入帧的方法。只有带有@EnableWebSocketMessageBroker 注解的类需要扩展，其他类（如带有@Controller 注解的类）保持不变。

import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.Map;
import java.util.List;
import java.util.HashMap;
import java.util.ArrayList;

import org.springframework.context.annotation.Configuration;
import org.springframework.messaging.simp.config.MessageBrokerRegistry;
import org.springframework.web.socket.config.annotation.AbstractWebSocketMessageBrokerConfigurer;
import org.springframework.web.socket.config.annotation.EnableWebSocketMessageBroker;
import org.springframework.web.socket.config.annotation.StompEndpointRegistry;
import org.springframework.messaging.simp.config.SimpleBrokerRegistration;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageHeaders;
import org.springframework.messaging.support.ChannelInterceptorAdapter;
import org.springframework.messaging.support.GenericMessage;
import org.springframework.messaging.simp.config.ChannelRegistration;
import org.springframework.messaging.simp.SimpMessageType;
import org.springframework.messaging.simp.stomp.StompCommand;
import org.springframework.messaging.MessageChannel;
import org.springframework.beans.factory.annotation.Autowired;

@Configuration
@EnableWebSocketMessageBroker
public class WebSocketConfig extends AbstractWebSocketMessageBrokerConfigurer {

    private static final Logger LOGGER = Logger.getLogger( WebSocketConfig.class.getName() );
    private MessageChannel outChannel;

    @Override
    public void configureClientInboundChannel(ChannelRegistration registration) {
        registration.interceptors( new InboundMessageInterceptor() );
    }

    @Override
    public void configureClientOutboundChannel(ChannelRegistration registration) {
        registration.interceptors( new OutboundMessageInterceptor() );
    }

    @Override
    public void configureMessageBroker(MessageBrokerRegistry config) {
// prefixes are application-dependent
        config.enableSimpleBroker("/topic");
        config.setApplicationDestinationPrefixes("/app");
    }

    @Override
    public void registerStompEndpoints(StompEndpointRegistry registry) {
        registry.addEndpoint("/note");
    }


    class InboundMessageInterceptor extends ChannelInterceptorAdapter {

        @SuppressWarnings("unchecked")
        public Message preSend(Message message, MessageChannel channel) {
            LOGGER.log( Level.SEVERE, "preSend: "+message );
            GenericMessage genericMessage = (GenericMessage)message;
            MessageHeaders headers = genericMessage.getHeaders();
            String simpSessionId = (String)headers.get( "simpSessionId" );
            if( ( SimpMessageType.MESSAGE.equals( headers.get( "simpMessageType" ) ) &&
                  StompCommand.SEND.equals( headers.get( "stompCommand" ) ) ) ||
                ( SimpMessageType.SUBSCRIBE.equals( headers.get( "simpMessageType" ) ) &&
                  StompCommand.SUBSCRIBE.equals( headers.get( "stompCommand" ) ) ) &&
                ( simpSessionId != null ) ) {
                Map<String,List<String>> nativeHeaders = (Map<String,List<String>>)headers.get( "nativeHeaders" );
                if( nativeHeaders != null ) {
                    List<String> receiptList = nativeHeaders.get( "receipt" );
                    if( receiptList != null ) {
                        String rid = (String)receiptList.get(0);
                        LOGGER.log( Level.SEVERE, "receipt requested: "+rid );
                        sendReceipt( rid, simpSessionId );
                    }
                }
            }
            return message;
        }

        private void sendReceipt( String rid, String simpSessionId ) {
            if( outChannel != null ) {
                HashMap<String,Object> rcptHeaders = new HashMap<String,Object>();
                rcptHeaders.put( "simpMessageType", SimpMessageType.OTHER );
                rcptHeaders.put( "stompCommand", StompCommand.RECEIPT );
                rcptHeaders.put( "simpSessionId", simpSessionId );
                HashMap<String,List<String>> nativeHeaders = new HashMap<String,List<String>>();
                ArrayList<String> receiptElements = new ArrayList<String>();
                receiptElements.add( rid );
                nativeHeaders.put( "receipt-id", receiptElements );
                rcptHeaders.put( "nativeHeaders",nativeHeaders );
                GenericMessage<byte[]> rcptMsg = new GenericMessage<byte[]>( new byte[0],new MessageHeaders( rcptHeaders ) );
                outChannel.send( rcptMsg );
            } else
                LOGGER.log( Level.SEVERE, "receipt NOT sent" );
        }
    }

    class OutboundMessageInterceptor extends ChannelInterceptorAdapter {
        public void postSend(Message message,
            MessageChannel channel,
            boolean sent) {
            LOGGER.log( Level.SEVERE, "postSend: "+message );
            outChannel = channel;
        }
    }
}

确实，它比应有的复杂得多，并且获取 outChannel 也不是很优雅。但它有效。 :-)

Answer 4

以上所有都过早发送回执帧。 以下为您提供所需的内容。

参考：https://github.com/spring-projects/spring-framework/issues/21848

@Configuration
static class WebSocketConfig implements WebSocketMessageBrokerConfigurer {

    private MessageChannel outChannel;

    @Autowired
    public WebSocketConfig(MessageChannel clientOutboundChannel) {
        this.outChannel = clientOutboundChannel;
    }

    @Override
    public void configureClientInboundChannel(ChannelRegistration registration) {

        registration.interceptors(new ExecutorChannelInterceptor() {

            @Override
            public void afterMessageHandled(Message<?> inMessage,
                    MessageChannel inChannel, MessageHandler handler, Exception ex) {

                StompHeaderAccessor inAccessor = StompHeaderAccessor.wrap(inMessage);
                String receipt = inAccessor.getReceipt();
                if (StringUtils.isEmpty(receipt)) {
                    return;
                }

                StompHeaderAccessor outAccessor = StompHeaderAccessor.create(StompCommand.RECEIPT);
                outAccessor.setSessionId(inAccessor.getSessionId());
                outAccessor.setReceiptId(receipt);
                outAccessor.setLeaveMutable(true);

                Message<byte[]> outMessage =
                        MessageBuilder.createMessage(new byte[0], outAccessor.getMessageHeaders());

                outChannel.send(outMessage);
            }
        });
    }
} 

Answer 5

这就是我最终要做的。

@Configuration
@EnableWebSocketMessageBroker
public class WebSocketMessageBrokerConfigurer
        implements org.springframework.web.socket.config.annotation.WebSocketMessageBrokerConfigurer {
        private MessageChannel outChannel;

    @Override
    public void configureClientInboundChannel(ChannelRegistration registration) {

        registration.interceptors(new ExecutorChannelInterceptor() {

            @Override
            public void afterMessageHandled(Message<?> inMessage,
                                            MessageChannel inChannel, MessageHandler handler, Exception ex) {
                if(outChannel == null) {
                    return;
                }

                StompHeaderAccessor inAccessor = StompHeaderAccessor.wrap(inMessage);
                String receipt = inAccessor.getReceipt();
                if (StringUtils.isEmpty(receipt)) {
                    return;
                }

                StompHeaderAccessor outAccessor = StompHeaderAccessor.create(StompCommand.RECEIPT);
                outAccessor.setSessionId(inAccessor.getSessionId());
                outAccessor.setReceiptId(receipt);
                outAccessor.setLeaveMutable(true);

                Message<byte[]> outMessage =
                    MessageBuilder.createMessage(new byte[0], outAccessor.getMessageHeaders());

                outChannel.send(outMessage);
            }
        });
    }

    public void configureClientOutboundChannel(ChannelRegistration registration) {
        registration.interceptors(new ExecutorChannelInterceptor() {
            @Override
            public void afterMessageHandled(Message<?> message, MessageChannel channel, MessageHandler handler, @Nullable Exception ex) {
                outChannel = channel;
            }
        });
    }
}

对于测试，您还必须使用 taskScheduler 配置 stompClient。这样才能执行处理收据的任务。

stompClient.setTaskScheduler(taskScheduler);

然后需要配置Session 和Receiptable 对象。例如在订阅对象上使用addReceiptTask。

        @Override
        public void afterConnected(StompSession session, StompHeaders connectedHeaders) {
            session.setAutoReceipt(true);
            StompSession.Subscription subscription = session.subscribe(topic, this);
            subscription.addReceiptTask(() -> {
                logger.info("Receipt for subscription ID {}", subscription.getSubscriptionId());
                connectedFuture.complete(null);
            });
            logger.info("Stomp Subscription ID is '{}' for topic '{}'.",
                    subscription.getSubscriptionId(), topic);

        }

如您所见，还有一个 connectedFuture 在处理订阅收据时完成。这允许测试知道何时可以开始向客户端发送数据。