Class Publisher (1.122.2)

A Cloud Pub/Sub publisher, that is associated with a specific topic at creation.

A Publisher provides built-in capabilities to automatically handle batching of messages, controlling memory utilization, and retrying API calls on transient errors.

With customizable options that control:

• Message batching: such as number of messages or max batch byte size.
• Retries: such as the maximum duration of retries for a failing batch of messages.

Publisher will use the credentials set on the channel, which uses application default credentials through GoogleCredentials#getApplicationDefault by default.

The maximum size of one request. Defined by the API.

The maximum number of messages in one request. Defined by the API.

Constructs a new Builder using the given topic.

Example of creating a Publisher.

 String projectName = "my_project";
 String topicName = "my_topic";
 ProjectTopicName topic = ProjectTopicName.create(projectName, topicName);
 Publisher publisher = Publisher.newBuilder(topic).build();
 try {
   // ...
 } finally {
   // When finished with the publisher, make sure to shutdown to free up resources.
   publisher.shutdown();
   publisher.awaitTermination(1, TimeUnit.MINUTES);
 }
 

Constructs a new Builder using the given topic.

Example of creating a Publisher.

 String topic = "projects/my_project/topics/my_topic";
 Publisher publisher = Publisher.newBuilder(topic).build();
 try {
   // ...
 } finally {
   // When finished with the publisher, make sure to shutdown to free up resources.
   publisher.shutdown();
   publisher.awaitTermination(1, TimeUnit.MINUTES);
 }
 

Wait for all work has completed execution after a #shutdown() request, or the timeout occurs, or the current thread is interrupted.

Call this method to make sure all resources are freed properly.

The batching settings configured on this Publisher.

Topic which the publisher publishes to.

Topic which the publisher publishes to.

Schedules the publishing of a message. The publishing of the message may occur immediately or be delayed based on the publisher batching options.

This method blocks in the downcall if using LimitExceededBehavior.Block in the flow control settings.

Example of publishing a message.

 String message = "my_message";
 ByteString data = ByteString.copyFromUtf8(message);
 PubsubMessage pubsubMessage = PubsubMessage.newBuilder().setData(data).build();
 ApiFuture<String> messageIdFuture = publisher.publish(pubsubMessage);
 ApiFutures.addCallback(messageIdFuture, new ApiFutureCallback<String>() {
   public void onSuccess(String messageId) {
     System.out.println("published with message id: " + messageId);
   }

   public void onFailure(Throwable t) {
     System.out.println("failed to publish: " + t);
   }
 }, MoreExecutors.directExecutor());
 

Publish any outstanding batches if non-empty. This method sends buffered messages, but does not wait for the send operations to complete. To wait for messages to send, call get on the futures returned from publish.

There may be non-recoverable problems with a request for an ordering key. In that case, all subsequent requests will fail until this method is called. If the key is not currently paused, calling this method will be a no-op.

Schedules immediate publishing of any outstanding messages and waits until all are processed.

Sends remaining outstanding messages and prevents future calls to publish. This method should be invoked prior to deleting the Publisher object in order to ensure that no pending messages are lost.