Workaround for listening on PubSub subscriptions even when StreamingPull stops silently

PubSubServiceExcerpt.java

// ... other dependencies ...

import com.google.api.core.ApiService;
import com.google.common.util.concurrent.MoreExecutors;
import com.google.cloud.pubsub.v1.MessageReceiver;
import com.google.cloud.pubsub.v1.Subscriber;
import com.google.pubsub.v1.Subscription;

import org.springframework.stereotype.Service;

@Service
public class PubSubService {
    // ... other code ...
    
    private static final long listenerErrorRetryDelayMs = 5000; // 5 seconds
    private static final long listenerRestartIntervalMs = 300000; // 5 minutes
    
    private static void sleep(final long ms) {
        try {
            Thread.sleep(ms);
        } catch (final InterruptedException interrupted) {
            // ignore
        }
    }

    private void createSubscriberWithListener(
            final Subscription subscription,
            final MessageReceiver receiver
    ) {
        while (true) {
            final Thread listenerThread = Thread.currentThread();
            final Subscriber subscriber = Subscriber
              .newBuilder(subscription.getName(), receiver)
              .build();

            subscriber.addListener(
                new Subscriber.Listener() {
                    @Override
                    public void failed(final Subscriber.State from, final Throwable t) {
                        sleep(listenerErrorRetryDelayMs);
                        listenerThread.interrupt();
                    }
                },
                MoreExecutors.directExecutor()
            );

            subscriber.startAsync().awaitRunning();
            sleep(listenerRestartIntervalMs);

            if (subscriber.state() == ApiService.State.RUNNING) {
                subscriber.stopAsync().awaitTerminated();
            }
        }
    }
}