import com.google.api.services.pubsub.model.AcknowledgeRequest; //导入依赖的package包/类
@Override
public void acknowledge(SubscriptionPath subscription, List<String> ackIds) throws IOException {
  AcknowledgeRequest request = new AcknowledgeRequest().setAckIds(ackIds);
  pubsub.projects()
        .subscriptions()
        .acknowledge(subscription.getPath(), request)
        .execute(); // ignore Empty result.
}
 

import com.google.api.services.pubsub.model.AcknowledgeRequest; //导入依赖的package包/类
private void ackPubsubMessage(String subscriptionName) {
  List<String> ackIds = ImmutableList.of(ackId);
  AcknowledgeRequest ackRequest = new AcknowledgeRequest().setAckIds(ackIds);
  try {
    pubsub.projects().subscriptions().acknowledge(subscriptionName, ackRequest).execute();
    logger.info("Successfully Acked Pubsub message");
  } catch (IOException e) {
    // we are unable to ack the message and it will get re-delivered(as a duplicate message).
    // since, we are only supporting QOS 1 for MQTT this is fine.
    logger.info("Unable to Ack Pubsub message");
  }
}
 

import com.google.api.services.pubsub.model.AcknowledgeRequest; //导入依赖的package包/类
private void ackPubsubMessage(List<String> ackIds) {
  AcknowledgeRequest ackRequest = new AcknowledgeRequest().setAckIds(ackIds);
  try {
    pubsub.projects().subscriptions().acknowledge(subscriptionName, ackRequest).execute();
    logger.info("Successfully Acked Pubsub message");
  } catch (IOException e) {
    // we are unable to ack the message and it will get re-delivered(as a duplicate message).
    // since, we are only supporting QOS 1 for MQTT this is fine.
    logger.info("Unable to Ack Pubsub message");
  }
}
 

import com.google.api.services.pubsub.model.AcknowledgeRequest; //导入依赖的package包/类
/**
 * Keeps pulling messages from the given subscription.
 *
 * @param client Cloud Pub/Sub client.
 * @param args Arguments as an array of String.
 * @throws IOException when Cloud Pub/Sub API calls fail.
 */
public static void pullMessages(final Pubsub client, final String[] args)
        throws IOException {
    Main.checkArgsLength(args, 3);
    String subscriptionName = PubsubUtils.getFullyQualifiedResourceName(
            PubsubUtils.ResourceType.SUBSCRIPTION, args[0], args[2]);
    PullRequest pullRequest = new PullRequest()
            .setReturnImmediately(false)
            .setMaxMessages(Main.BATCH_SIZE);

    do {
        PullResponse pullResponse;
        pullResponse = client.projects().subscriptions()
                .pull(subscriptionName, pullRequest)
                .execute();
        List<String> ackIds = new ArrayList<>(Main.BATCH_SIZE);
        List<ReceivedMessage> receivedMessages =
                pullResponse.getReceivedMessages();
        if (receivedMessages != null) {
            for (ReceivedMessage receivedMessage : receivedMessages) {
                PubsubMessage pubsubMessage =
                        receivedMessage.getMessage();
                if (pubsubMessage != null
                        && pubsubMessage.decodeData() != null) {
                    System.out.println(
                            new String(pubsubMessage.decodeData(),
                                    "UTF-8"));
                }
                ackIds.add(receivedMessage.getAckId());
            }
            AcknowledgeRequest ackRequest = new AcknowledgeRequest();
            ackRequest.setAckIds(ackIds);
            client.projects().subscriptions()
                    .acknowledge(subscriptionName, ackRequest)
                    .execute();
        }
    } while (System.getProperty(Main.LOOP_ENV_NAME) != null);
}
 

import com.google.api.services.pubsub.model.AcknowledgeRequest; //导入依赖的package包/类
@Override
public void run() {
	try {
		while (!pubsubReceiver.isStopped()) {

			final PullRequest pullRequest = new PullRequest().setReturnImmediately(false)
					.setMaxMessages(pubsubReceiver.getBatchSize());
			PullResponse pullResponse;
			pullResponse = pubsubClient.projects().subscriptions().pull(pubsubReceiver.getSubscription(), pullRequest)
					.execute();
			final List<ReceivedMessage> receivedMessages = pullResponse.getReceivedMessages();

			if (CollectionUtils.isNotEmpty(receivedMessages)) {

				final List<String> messages = new ArrayList<>(pubsubReceiver.getBatchSize());
				final List<String> ackIds = new ArrayList<>(pubsubReceiver.getBatchSize());
				for (final ReceivedMessage receivedMessage : receivedMessages) {
					final PubsubMessage pubsubMessage = receivedMessage.getMessage();

					if (pubsubMessage != null) {
						if (decodeData) {
							messages.add(new String(pubsubMessage.decodeData(), StandardCharsets.UTF_8));
						} else {
							messages.add(pubsubMessage.getData());
						}
					}
					ackIds.add(receivedMessage.getAckId());
				}

				if (CollectionUtils.isNotEmpty(messages)) {
					pubsubReceiver.store(messages.iterator());
				}

				final AcknowledgeRequest ackRequest = new AcknowledgeRequest().setAckIds(ackIds);
				pubsubClient.projects().subscriptions().acknowledge(pubsubReceiver.getSubscription(), ackRequest)
						.execute();
			}
		}
	} catch (Throwable t) {
		pubsubReceiver.restart(
				"Error while fetching messages from pubsub for subscription " + pubsubReceiver.getSubscription(), t);
	}

}