PubSub with spring: know the message is publish or not? - spring-boot

Question

My publisher code look like this:
public abstract class PubSubPublisher {
private static final Logger LOGGER = LoggerFactory.getLogger(PubSubPublisher.class);
private final PubSubTemplate pubSubTemplate;
protected PubSubPublisher(PubSubTemplate pubSubTemplate) {
this.pubSubTemplate = pubSubTemplate;
}
protected abstract String topic(String topicName);
public void publish(String topicName, String message) throws StatusRuntimeException {
LOGGER.info("Publishing to topic [{}]. Message: [{}]", topicName, message);
pubSubTemplate.publish(topicName, message);
}
}
My Component
#Component
public class HelloPubSubPublisher extends PubSubPublisher {
#Autowired
public HelloPubSubPublisher(PubSubTemplate pubSubTemplate) throws StatusRuntimeException{
super(pubSubTemplate);
}
#Override
protected String topic(String topicName) {
return topicName;
}
}
Now on my service layer how do i get weather i successful publish the message to topic or not, note all the google api are async which i am using.
try {
publisher.publish(topicName, payload);
}catch (Exception e) {
LOGGER.error("ioException occured: "+e);
throw new TopicNotFoundException();
}
Unfortunately, I am not able to capture the any error, program cursor is not going into the catch block.
Ultimately, I wanted to know weather the code is push the message into topic if not then I have to log it and throw that error to client, which is not happen with my current code with proper exception handling.
Any help or guidance is appreciated, thanks.

Answer 1

Using the function publish() you should be able to capture a future where you can check if the message was published or not.
You have an example of it on Google's PubSub documentation:
// Once published, returns a server-assigned message id (unique within the topic)
ApiFuture<String> future = publisher.publish(pubsubMessage);
// Add an asynchronous callback to handle success / failure
ApiFutures.addCallback(
future,
new ApiFutureCallback<String>() {
#Override
public void onFailure(Throwable throwable) {
if (throwable instanceof ApiException) {
ApiException apiException = ((ApiException) throwable);
// details on the API exception
System.out.println(apiException.getStatusCode().getCode());
System.out.println(apiException.isRetryable());
}
System.out.println("Error publishing message : " + message);
}
#Override
public void onSuccess(String messageId) {
// Once published, returns server-assigned message ids (unique within the topic)
System.out.println(messageId);
}
},
MoreExecutors.directExecutor());