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https://github.com/googleapis/java-pubsub

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Host: GitHub
URL: https://github.com/googleapis/java-pubsub
Owner: googleapis
License: apache-2.0
Created: 2019-08-20T22:07:36.000Z (over 5 years ago)
Default Branch: main
Last Pushed: 2024-10-24T02:29:29.000Z (2 months ago)
Last Synced: 2024-10-24T09:10:07.557Z (2 months ago)
Language: Java
Size: 7.44 MB
Stars: 128
Watchers: 57
Forks: 90
Open Issues: 26
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- Contributing: CONTRIBUTING.md
- License: LICENSE
- Code of conduct: CODE_OF_CONDUCT.md
- Codeowners: .github/CODEOWNERS
- Security: SECURITY.md
Awesome Lists containing this project

README

        # Google Cloud Pub/Sub Client for Java

Java idiomatic client for [Cloud Pub/Sub][product-docs].

[![Maven][maven-version-image]][maven-version-link]

![Stability][stability-image]

- [Product Documentation][product-docs]

- [Client Library Documentation][javadocs]

## Quickstart

If you are using Maven with [BOM][libraries-bom], add this to your pom.xml file:

```xml

  

    

      com.google.cloud

      libraries-bom

      26.51.0

      pom

      import

    

  

  

    com.google.cloud

    google-cloud-pubsub

  

```

If you are using Maven without the BOM, add this to your dependencies:

```xml

  com.google.cloud

  google-cloud-pubsub

  1.134.2

```

If you are using Gradle 5.x or later, add this to your dependencies:

```Groovy

implementation platform('com.google.cloud:libraries-bom:26.51.0')

implementation 'com.google.cloud:google-cloud-pubsub'

```

If you are using Gradle without BOM, add this to your dependencies:

```Groovy

implementation 'com.google.cloud:google-cloud-pubsub:1.135.0'

```

If you are using SBT, add this to your dependencies:

```Scala

libraryDependencies += "com.google.cloud" % "google-cloud-pubsub" % "1.135.0"

```

## Authentication

See the [Authentication][authentication] section in the base directory's README.

## Authorization

The client application making API calls must be granted [authorization scopes][auth-scopes] required for the desired Cloud Pub/Sub APIs, and the authenticated principal must have the [IAM role(s)][predefined-iam-roles] required to access GCP resources using the Cloud Pub/Sub API calls.

## Getting Started

### Prerequisites

You will need a [Google Cloud Platform Console][developer-console] project with the Cloud Pub/Sub [API enabled][enable-api].

You will need to [enable billing][enable-billing] to use Google Cloud Pub/Sub.

[Follow these instructions][create-project] to get your project set up. You will also need to set up the local development environment by

[installing the Google Cloud Command Line Interface][cloud-cli] and running the following commands in command line:

`gcloud auth login` and `gcloud config set project [YOUR PROJECT ID]`.

### Installation and setup

You'll need to obtain the `google-cloud-pubsub` library.  See the [Quickstart](#quickstart) section

to add `google-cloud-pubsub` as a dependency in your code.

## About Cloud Pub/Sub

[Cloud Pub/Sub][product-docs] is designed to provide reliable, many-to-many, asynchronous messaging between applications. Publisher applications can send messages to a topic and other applications can subscribe to that topic to receive the messages. By decoupling senders and receivers, Google Cloud Pub/Sub allows developers to communicate between independently written applications.

See the [Cloud Pub/Sub client library docs][javadocs] to learn how to

use this Cloud Pub/Sub Client Library.

#### Creating a topic

With Pub/Sub you can create topics. A topic is a named resource to which messages are sent by

publishers. Add the following imports at the top of your file:

```java

import com.google.cloud.pubsub.v1.TopicAdminClient;

import com.google.pubsub.v1.TopicName;

```

Then, to create the topic, use the following code:

```java

TopicName topic = TopicName.of("test-project", "test-topic");

try (TopicAdminClient topicAdminClient = TopicAdminClient.create()) {

  topicAdminClient.createTopic(topic);

}

```

#### Publishing messages

With Pub/Sub you can publish messages to a topic. Add the following import at the top of your file:

```java

import com.google.api.core.ApiFuture;

import com.google.api.core.ApiFutureCallback;

import com.google.api.core.ApiFutures;

import com.google.cloud.pubsub.v1.Publisher;

import com.google.common.util.concurrent.MoreExecutors;

import com.google.protobuf.ByteString;

import com.google.pubsub.v1.PubsubMessage;

```

Then, to publish messages asynchronously, use the following code:

```java

Publisher publisher = null;

try {

  publisher = Publisher.newBuilder(topic).build();

  ByteString data = ByteString.copyFromUtf8("my-message");

  PubsubMessage pubsubMessage = PubsubMessage.newBuilder().setData(data).build();

  ApiFuture messageIdFuture = publisher.publish(pubsubMessage);

  ApiFutures.addCallback(messageIdFuture, new ApiFutureCallback() {

    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());

  //...

} finally {

  if (publisher != null) {

    publisher.shutdown();

    publisher.awaitTermination(1, TimeUnit.MINUTES);

  }

}

```

#### Creating a subscription

With Pub/Sub you can create subscriptions. A subscription represents the stream of messages from a

single, specific topic. Add the following imports at the top of your file:

```java

import com.google.cloud.pubsub.v1.SubscriptionAdminClient;

import com.google.pubsub.v1.PushConfig;

import com.google.pubsub.v1.SubscriptionName;

import com.google.pubsub.v1.TopicName;

```

Then, to create the subscription, use the following code:

```java

TopicName topic = TopicName.of("test-project", "test-topic");

SubscriptionName subscription = SubscriptionName.of("test-project", "test-subscription");

try (SubscriptionAdminClient subscriptionAdminClient = SubscriptionAdminClient.create()) {

  subscriptionAdminClient.createSubscription(subscription, topic, PushConfig.getDefaultInstance(), 0);

}

```

#### Pulling messages

With Pub/Sub you can pull messages from a subscription. Add the following imports at the top of your

file:

```java

import com.google.cloud.pubsub.v1.AckReplyConsumer;

import com.google.cloud.pubsub.v1.MessageReceiver;

import com.google.cloud.pubsub.v1.Subscriber;

import com.google.common.util.concurrent.MoreExecutors;

import com.google.pubsub.v1.PubsubMessage;

import com.google.pubsub.v1.SubscriptionName;

import com.google.pubsub.v1.TopicName;

```

Then, to pull messages asynchronously, use the following code:

```java

SubscriptionName subscription = SubscriptionName.of("test-project", "test-subscription");

MessageReceiver receiver =

  new MessageReceiver() {

    @Override

    public void receiveMessage(PubsubMessage message, AckReplyConsumer consumer) {

      System.out.println("got message: " + message.getData().toStringUtf8());

      consumer.ack();

    }

  };

Subscriber subscriber = null;

try {

  subscriber = Subscriber.newBuilder(subscription.toString(), receiver).build();

  subscriber.addListener(

    new Subscriber.Listener() {

      @Override

      public void failed(Subscriber.State from, Throwable failure) {

        // Handle failure. This is called when the Subscriber encountered a fatal error and is shutting down.

        System.err.println(failure);

      }

    },

    MoreExecutors.directExecutor());

  subscriber.startAsync().awaitRunning();

  //...

} finally {

  if (subscriber != null) {

    subscriber.stopAsync();

  }

}

```

#### Complete source code

In [CreateTopicAndPublishMessages.java](https://github.com/googleapis/google-cloud-java/tree/master/google-cloud-examples/src/main/java/com/google/cloud/examples/pubsub/snippets/CreateTopicAndPublishMessages.java) and [CreateSubscriptionAndConsumeMessages.java](https://github.com/googleapis/google-cloud-java/tree/master/google-cloud-examples/src/main/java/com/google/cloud/examples/pubsub/snippets/CreateSubscriptionAndConsumeMessages.java) we put together all the code shown above into two programs. The programs assume that you are running on Compute Engine, App Engine Flexible or from your own desktop.

## Samples

Samples are in the [`samples/`](https://github.com/googleapis/java-pubsub/tree/main/samples) directory.

| Sample                      | Source Code                       | Try it |

| --------------------------- | --------------------------------- | ------ |

| Commit Avro Schema Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/CommitAvroSchemaExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/CommitAvroSchemaExample.java) |

| Commit Proto Schema Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/CommitProtoSchemaExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/CommitProtoSchemaExample.java) |

| Create Avro Schema Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/CreateAvroSchemaExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/CreateAvroSchemaExample.java) |

| Create Big Query Subscription Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/CreateBigQuerySubscriptionExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/CreateBigQuerySubscriptionExample.java) |

| Create Cloud Storage Subscription Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/CreateCloudStorageSubscriptionExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/CreateCloudStorageSubscriptionExample.java) |

| Create Proto Schema Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/CreateProtoSchemaExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/CreateProtoSchemaExample.java) |

| Create Pull Subscription Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/CreatePullSubscriptionExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/CreatePullSubscriptionExample.java) |

| Create Push Subscription Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/CreatePushSubscriptionExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/CreatePushSubscriptionExample.java) |

| Create Subscription With Dead Letter Policy Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/CreateSubscriptionWithDeadLetterPolicyExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/CreateSubscriptionWithDeadLetterPolicyExample.java) |

| Create Subscription With Exactly Once Delivery | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/CreateSubscriptionWithExactlyOnceDelivery.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/CreateSubscriptionWithExactlyOnceDelivery.java) |

| Create Subscription With Filtering | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/CreateSubscriptionWithFiltering.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/CreateSubscriptionWithFiltering.java) |

| Create Subscription With Ordering | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/CreateSubscriptionWithOrdering.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/CreateSubscriptionWithOrdering.java) |

| Create Topic Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/CreateTopicExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/CreateTopicExample.java) |

| Create Topic With Cloud Storage Ingestion Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/CreateTopicWithCloudStorageIngestionExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/CreateTopicWithCloudStorageIngestionExample.java) |

| Create Topic With Kinesis Ingestion Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/CreateTopicWithKinesisIngestionExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/CreateTopicWithKinesisIngestionExample.java) |

| Create Topic With Schema Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/CreateTopicWithSchemaExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/CreateTopicWithSchemaExample.java) |

| Create Topic With Schema Revisions Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/CreateTopicWithSchemaRevisionsExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/CreateTopicWithSchemaRevisionsExample.java) |

| Create Unwrapped Push Subscription Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/CreateUnwrappedPushSubscriptionExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/CreateUnwrappedPushSubscriptionExample.java) |

| Delete Schema Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/DeleteSchemaExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/DeleteSchemaExample.java) |

| Delete Schema Revision Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/DeleteSchemaRevisionExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/DeleteSchemaRevisionExample.java) |

| Delete Subscription Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/DeleteSubscriptionExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/DeleteSubscriptionExample.java) |

| Delete Topic Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/DeleteTopicExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/DeleteTopicExample.java) |

| Detach Subscription Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/DetachSubscriptionExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/DetachSubscriptionExample.java) |

| Get Schema Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/GetSchemaExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/GetSchemaExample.java) |

| Get Schema Revision Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/GetSchemaRevisionExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/GetSchemaRevisionExample.java) |

| Get Subscription Policy Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/GetSubscriptionPolicyExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/GetSubscriptionPolicyExample.java) |

| Get Topic Policy Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/GetTopicPolicyExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/GetTopicPolicyExample.java) |

| List Schema Revisions Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/ListSchemaRevisionsExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/ListSchemaRevisionsExample.java) |

| List Schemas Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/ListSchemasExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/ListSchemasExample.java) |

| List Subscriptions In Project Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/ListSubscriptionsInProjectExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/ListSubscriptionsInProjectExample.java) |

| List Subscriptions In Topic Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/ListSubscriptionsInTopicExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/ListSubscriptionsInTopicExample.java) |

| List Topics Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/ListTopicsExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/ListTopicsExample.java) |

| Open Telemetry Publisher Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/OpenTelemetryPublisherExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/OpenTelemetryPublisherExample.java) |

| Open Telemetry Subscriber Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/OpenTelemetrySubscriberExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/OpenTelemetrySubscriberExample.java) |

| Optimistic Subscribe Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/OptimisticSubscribeExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/OptimisticSubscribeExample.java) |

| Publish Avro Records Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/PublishAvroRecordsExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/PublishAvroRecordsExample.java) |

| Publish Protobuf Messages Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/PublishProtobufMessagesExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/PublishProtobufMessagesExample.java) |

| Publish With Batch Settings Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/PublishWithBatchSettingsExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/PublishWithBatchSettingsExample.java) |

| Publish With Concurrency Control Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/PublishWithConcurrencyControlExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/PublishWithConcurrencyControlExample.java) |

| Publish With Custom Attributes Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/PublishWithCustomAttributesExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/PublishWithCustomAttributesExample.java) |

| Publish With Error Handler Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/PublishWithErrorHandlerExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/PublishWithErrorHandlerExample.java) |

| Publish With Flow Control Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/PublishWithFlowControlExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/PublishWithFlowControlExample.java) |

| Publish With Grpc Compression Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/PublishWithGrpcCompressionExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/PublishWithGrpcCompressionExample.java) |

| Publish With Ordering Keys | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/PublishWithOrderingKeys.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/PublishWithOrderingKeys.java) |

| Publish With Retry Settings Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/PublishWithRetrySettingsExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/PublishWithRetrySettingsExample.java) |

| Publisher Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/PublisherExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/PublisherExample.java) |

| Receive Messages With Delivery Attempts Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/ReceiveMessagesWithDeliveryAttemptsExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/ReceiveMessagesWithDeliveryAttemptsExample.java) |

| Remove Dead Letter Policy Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/RemoveDeadLetterPolicyExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/RemoveDeadLetterPolicyExample.java) |

| Resume Publish With Ordering Keys | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/ResumePublishWithOrderingKeys.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/ResumePublishWithOrderingKeys.java) |

| Rollback Schema Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/RollbackSchemaExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/RollbackSchemaExample.java) |

| Set Subscription Policy Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/SetSubscriptionPolicyExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/SetSubscriptionPolicyExample.java) |

| Set Topic Policy Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/SetTopicPolicyExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/SetTopicPolicyExample.java) |

| Subscribe Async Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/SubscribeAsyncExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/SubscribeAsyncExample.java) |

| Subscribe Sync Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/SubscribeSyncExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/SubscribeSyncExample.java) |

| Subscribe Sync With Lease Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/SubscribeSyncWithLeaseExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/SubscribeSyncWithLeaseExample.java) |

| Subscribe With Avro Schema Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/SubscribeWithAvroSchemaExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/SubscribeWithAvroSchemaExample.java) |

| Subscribe With Avro Schema Revisions Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/SubscribeWithAvroSchemaRevisionsExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/SubscribeWithAvroSchemaRevisionsExample.java) |

| Subscribe With Concurrency Control Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/SubscribeWithConcurrencyControlExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/SubscribeWithConcurrencyControlExample.java) |

| Subscribe With Custom Attributes Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/SubscribeWithCustomAttributesExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/SubscribeWithCustomAttributesExample.java) |

| Subscribe With Error Listener Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/SubscribeWithErrorListenerExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/SubscribeWithErrorListenerExample.java) |

| Subscribe With Exactly Once Consumer With Response Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/SubscribeWithExactlyOnceConsumerWithResponseExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/SubscribeWithExactlyOnceConsumerWithResponseExample.java) |

| Subscribe With Flow Control Settings Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/SubscribeWithFlowControlSettingsExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/SubscribeWithFlowControlSettingsExample.java) |

| Subscribe With Proto Schema Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/SubscribeWithProtoSchemaExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/SubscribeWithProtoSchemaExample.java) |

| Test Subscription Permissions Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/TestSubscriptionPermissionsExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/TestSubscriptionPermissionsExample.java) |

| Test Topic Permissions Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/TestTopicPermissionsExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/TestTopicPermissionsExample.java) |

| Update Dead Letter Policy Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/UpdateDeadLetterPolicyExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/UpdateDeadLetterPolicyExample.java) |

| Update Push Configuration Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/UpdatePushConfigurationExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/UpdatePushConfigurationExample.java) |

| Update Topic Schema Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/UpdateTopicSchemaExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/UpdateTopicSchemaExample.java) |

| Update Topic Type Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/UpdateTopicTypeExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/UpdateTopicTypeExample.java) |

| Use Pub Sub Emulator Example | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/pubsub/UsePubSubEmulatorExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/pubsub/UsePubSubEmulatorExample.java) |

| State | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/utilities/State.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/utilities/State.java) |

| State Proto | [source code](https://github.com/googleapis/java-pubsub/blob/main/samples/snippets/src/main/java/utilities/StateProto.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-pubsub&page=editor&open_in_editor=samples/snippets/src/main/java/utilities/StateProto.java) |

## Troubleshooting

To get help, follow the instructions in the [shared Troubleshooting document][troubleshooting].

## Transport

Cloud Pub/Sub uses both gRPC and HTTP/JSON for the transport layer.

## Supported Java Versions

Java 8 or above is required for using this client.

Google's Java client libraries,

[Google Cloud Client Libraries][cloudlibs]

and

[Google Cloud API Libraries][apilibs],

follow the

[Oracle Java SE support roadmap][oracle]

(see the Oracle Java SE Product Releases section).

### For new development

In general, new feature development occurs with support for the lowest Java

LTS version covered by  Oracle's Premier Support (which typically lasts 5 years

from initial General Availability). If the minimum required JVM for a given

library is changed, it is accompanied by a [semver][semver] major release.

Java 11 and (in September 2021) Java 17 are the best choices for new

development.

### Keeping production systems current

Google tests its client libraries with all current LTS versions covered by

Oracle's Extended Support (which typically lasts 8 years from initial

General Availability).

#### Legacy support

Google's client libraries support legacy versions of Java runtimes with long

term stable libraries that don't receive feature updates on a best efforts basis

as it may not be possible to backport all patches.

Google provides updates on a best efforts basis to apps that continue to use

Java 7, though apps might need to upgrade to current versions of the library

that supports their JVM.

#### Where to find specific information

The latest versions and the supported Java versions are identified on

the individual GitHub repository `github.com/GoogleAPIs/java-SERVICENAME`

and on [google-cloud-java][g-c-j].

## Versioning

This library follows [Semantic Versioning](http://semver.org/).

## Contributing

Contributions to this library are always welcome and highly encouraged.

See [CONTRIBUTING][contributing] for more information how to get started.

Please note that this project is released with a Contributor Code of Conduct. By participating in

this project you agree to abide by its terms. See [Code of Conduct][code-of-conduct] for more

information.

## License

Apache 2.0 - See [LICENSE][license] for more information.

## CI Status

Java Version | Status

------------ | ------

Java 8 | [![Kokoro CI][kokoro-badge-image-2]][kokoro-badge-link-2]

Java 8 OSX | [![Kokoro CI][kokoro-badge-image-3]][kokoro-badge-link-3]

Java 8 Windows | [![Kokoro CI][kokoro-badge-image-4]][kokoro-badge-link-4]

Java 11 | [![Kokoro CI][kokoro-badge-image-5]][kokoro-badge-link-5]

Java is a registered trademark of Oracle and/or its affiliates.

[product-docs]: https://cloud.google.com/pubsub/docs/

[javadocs]: https://cloud.google.com/java/docs/reference/google-cloud-pubsub/latest/history

[kokoro-badge-image-1]: http://storage.googleapis.com/cloud-devrel-public/java/badges/java-pubsub/java7.svg

[kokoro-badge-link-1]: http://storage.googleapis.com/cloud-devrel-public/java/badges/java-pubsub/java7.html

[kokoro-badge-image-2]: http://storage.googleapis.com/cloud-devrel-public/java/badges/java-pubsub/java8.svg

[kokoro-badge-link-2]: http://storage.googleapis.com/cloud-devrel-public/java/badges/java-pubsub/java8.html

[kokoro-badge-image-3]: http://storage.googleapis.com/cloud-devrel-public/java/badges/java-pubsub/java8-osx.svg

[kokoro-badge-link-3]: http://storage.googleapis.com/cloud-devrel-public/java/badges/java-pubsub/java8-osx.html

[kokoro-badge-image-4]: http://storage.googleapis.com/cloud-devrel-public/java/badges/java-pubsub/java8-win.svg

[kokoro-badge-link-4]: http://storage.googleapis.com/cloud-devrel-public/java/badges/java-pubsub/java8-win.html

[kokoro-badge-image-5]: http://storage.googleapis.com/cloud-devrel-public/java/badges/java-pubsub/java11.svg

[kokoro-badge-link-5]: http://storage.googleapis.com/cloud-devrel-public/java/badges/java-pubsub/java11.html

[stability-image]: https://img.shields.io/badge/stability-stable-green

[maven-version-image]: https://img.shields.io/maven-central/v/com.google.cloud/google-cloud-pubsub.svg

[maven-version-link]: https://central.sonatype.com/artifact/com.google.cloud/google-cloud-pubsub/1.135.0

[authentication]: https://github.com/googleapis/google-cloud-java#authentication

[auth-scopes]: https://developers.google.com/identity/protocols/oauth2/scopes

[predefined-iam-roles]: https://cloud.google.com/iam/docs/understanding-roles#predefined_roles

[iam-policy]: https://cloud.google.com/iam/docs/overview#cloud-iam-policy

[developer-console]: https://console.developers.google.com/

[create-project]: https://cloud.google.com/resource-manager/docs/creating-managing-projects

[cloud-cli]: https://cloud.google.com/cli

[troubleshooting]: https://github.com/googleapis/google-cloud-java/blob/main/TROUBLESHOOTING.md

[contributing]: https://github.com/googleapis/java-pubsub/blob/main/CONTRIBUTING.md

[code-of-conduct]: https://github.com/googleapis/java-pubsub/blob/main/CODE_OF_CONDUCT.md#contributor-code-of-conduct

[license]: https://github.com/googleapis/java-pubsub/blob/main/LICENSE

[enable-billing]: https://cloud.google.com/apis/docs/getting-started#enabling_billing

[enable-api]: https://console.cloud.google.com/flows/enableapi?apiid=pubsub.googleapis.com

[libraries-bom]: https://github.com/GoogleCloudPlatform/cloud-opensource-java/wiki/The-Google-Cloud-Platform-Libraries-BOM

[shell_img]: https://gstatic.com/cloudssh/images/open-btn.png

[semver]: https://semver.org/

[cloudlibs]: https://cloud.google.com/apis/docs/client-libraries-explained

[apilibs]: https://cloud.google.com/apis/docs/client-libraries-explained#google_api_client_libraries

[oracle]: https://www.oracle.com/java/technologies/java-se-support-roadmap.html

[g-c-j]: http://github.com/googleapis/google-cloud-java