How to intercept Spring Cloud Stream messages?

Question

Spring allows interception of messages for many of their products, like RestTemplate and SpringMVC. Is it possible to intercept Spring Cloud Stream messages? For both incoming and outgoing messages.

Answer 1

Was able to intercept inbound and outbound Spring Cloud Stream messages using the GlobalChannelInterceptor annotation and ChannelInterceptor interface. See sample below.

import org.springframework.integration.config.GlobalChannelInterceptor;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageChannel;
import org.springframework.messaging.support.ChannelInterceptor;
import org.springframework.stereotype.Component;

@Component
@GlobalChannelInterceptor
public class Interceptor implements ChannelInterceptor {

    private final Logger log = LoggerFactory.getLogger(Interceptor.class);

    @Override
    public Message<?> preSend(Message<?> msg, MessageChannel mc) {
        log.info("In preSend");
        return msg;
    }

    @Override
    public void postSend(Message<?> msg, MessageChannel mc, boolean bln) {
        log.info("In postSend");
    }

    @Override
    public void afterSendCompletion(Message<?> msg, MessageChannel mc, boolean bln, Exception excptn) {
        log.info("In afterSendCompletion");
    }

    @Override
    public boolean preReceive(MessageChannel mc) {
        log.info("In preReceive");
        return true;
    }

    @Override
    public Message<?> postReceive(Message<?> msg, MessageChannel mc) {
        log.info("In postReceive");
        return msg;
    }

    @Override
    public void afterReceiveCompletion(Message<?> msg, MessageChannel mc, Exception excptn) {
        log.info("In afterReceiveCompletion");
    }

}