Quarkus Reactive Messaging - Exception Handler

We use Quarkus Messaging (with the "smallrye-jms" extension in order to connect to IBM MQ) with a converter to transform the messages received in strings, into a Java object.

When receiving an incoming message in "queue_A", we must produce a message in one of the following 2 destinations:

• "queue_A_error": if a problem is encountered during the conversion of the incoming message. The new message to be produced in this destination is a message whose payload is a string in JSON format (containing the original payload, as well as the list of all the errors encountered).
• "queue_B": with a message containing the original object serialized in JSON

How can we implement this error handling use-case with Quarkus Messaging?

You could do something like this:

@Inject @Channel("queue_A_error") 
Emitter<MyErrorMsg> emitter;

@Inject 
ObjectMapper mapper;

@Incoming("incoming_queue")
@Outgoing("queue_B")
public MyMessage handleMsg(String payload) {
  try {
     return this.mapper.readValue(payload, MyMessage.class);
  } catch (Exception e) {
     this.emitter.send(new MyErrorMsg(payload, e));
     return null;
  }
}

Note, I didn't test this code and I hope it helps you.

Edit: @JYC, I see that it is also possible to intercept incoming messages, see this link: https://smallrye.io/smallrye-reactive-messaging/4.25.0/concepts/decorators/#incominginterceptor

This can be handy if you want to globally implement error handling.

Edit 2: another option is to configure a DLQ:

mp.messaging.incoming.your-channel-name.dead-letter-queue=your-dead-letter-queue-name