com.google.api.services.pubsub.Pubsub Java Examples

@Override
public PubsubClient newClient(
    @Nullable String timestampAttribute, @Nullable String idAttribute, PubsubOptions options)
    throws IOException {
  Pubsub pubsub =
      new Builder(
              Transport.getTransport(),
              Transport.getJsonFactory(),
              chainHttpRequestInitializer(
                  options.getGcpCredential(),
                  // Do not log 404. It clutters the output and is possibly even required by the
                  // caller.
                  new RetryHttpRequestInitializer(ImmutableList.of(404))))
          .setRootUrl(options.getPubsubRootUrl())
          .setApplicationName(options.getAppName())
          .setGoogleClientRequestInitializer(options.getGoogleApiTrace())
          .build();
  return new PubsubJsonClient(timestampAttribute, idAttribute, pubsub);
}
 

/**
 * Builds a new Pubsub client and returns it.
 *
 * @param httpTransport HttpTransport for Pubsub client.
 * @param jsonFactory JsonFactory for Pubsub client.
 * @return Pubsub client.
 * @throws IOException when we can not get the default credentials.
 */
public static Pubsub getClient(final HttpTransport httpTransport,
                               final JsonFactory jsonFactory)
        throws IOException {
    Preconditions.checkNotNull(httpTransport);
    Preconditions.checkNotNull(jsonFactory);
    GoogleCredential credential = GoogleCredential.getApplicationDefault();
    if (credential.createScopedRequired()) {
        credential = credential.createScoped(PubsubScopes.all());
    }
    // Please use custom HttpRequestInitializer for automatic
    // retry upon failures.
    HttpRequestInitializer initializer =
            new RetryHttpInitializerWrapper(credential);
    return new Pubsub.Builder(httpTransport, jsonFactory, initializer)
            .setApplicationName(APPLICATION_NAME)
            .build();
}
 

/**
     * Setup authorization for local app based on private key.
     * See <a href="https://cloud.google.com/pubsub/configure">cloud.google.com/pubsub/configure</a>
     */
    private void createClient(String private_key_file, String email) throws IOException, GeneralSecurityException {
        HttpTransport transport = GoogleNetHttpTransport.newTrustedTransport();
        GoogleCredential credential = new GoogleCredential.Builder()
                .setTransport(transport)
                .setJsonFactory(JSON_FACTORY)
                .setServiceAccountScopes(PubsubScopes.all())
                .setServiceAccountId(email)
                .setServiceAccountPrivateKeyFromP12File(new File(private_key_file))
                .build();
        // Please use custom HttpRequestInitializer for automatic retry upon failures.
//        HttpRequestInitializer initializer = new RetryHttpInitializerWrapper(credential);
        pubsub = new Pubsub.Builder(transport, JSON_FACTORY, credential)
                .setApplicationName("eaipubsub")
                .build();
    }
 

/** Builds a new Pubsub client and returns it. */
public static Pubsub getClient(final HttpTransport httpTransport, final JsonFactory jsonFactory)
    throws IOException {
  checkNotNull(httpTransport);
  checkNotNull(jsonFactory);
  GoogleCredential credential =
      GoogleCredential.getApplicationDefault(httpTransport, jsonFactory);
  if (credential.createScopedRequired()) {
    credential = credential.createScoped(PubsubScopes.all());
  }
  if (credential.getClientAuthentication() != null) {
    System.out.println(
        "\n***Warning! You are not using service account credentials to "
            + "authenticate.\nYou need to use service account credentials for this example,"
            + "\nsince user-level credentials do not have enough pubsub quota,\nand so you will run "
            + "out of PubSub quota very quickly.\nSee "
            + "https://developers.google.com/identity/protocols/application-default-credentials.");
    System.exit(1);
  }
  HttpRequestInitializer initializer = new RetryHttpInitializerWrapper(credential);
  return new Pubsub.Builder(httpTransport, jsonFactory, initializer)
      .setApplicationName(APP_NAME)
      .build();
}
 

/** Builds a new Pubsub client and returns it. */
public static Pubsub getClient(final HttpTransport httpTransport, final JsonFactory jsonFactory)
    throws IOException {
  checkNotNull(httpTransport);
  checkNotNull(jsonFactory);
  GoogleCredential credential =
      GoogleCredential.getApplicationDefault(httpTransport, jsonFactory);
  if (credential.createScopedRequired()) {
    credential = credential.createScoped(PubsubScopes.all());
  }
  if (credential.getClientAuthentication() != null) {
    System.out.println(
        "\n***Warning! You are not using service account credentials to "
            + "authenticate.\nYou need to use service account credentials for this example,"
            + "\nsince user-level credentials do not have enough pubsub quota,\nand so you will run "
            + "out of PubSub quota very quickly.\nSee "
            + "https://developers.google.com/identity/protocols/application-default-credentials.");
    System.exit(1);
  }
  HttpRequestInitializer initializer = new RetryHttpInitializerWrapper(credential);
  return new Pubsub.Builder(httpTransport, jsonFactory, initializer)
      .setApplicationName(APP_NAME)
      .build();
}
 

/**
 * Creates a Cloud Pub/Sub topic if it doesn't exist.
 *
 * @param client Pubsub client object.
 * @throws IOException when API calls to Cloud Pub/Sub fails.
 */
private void setupTopic(final Pubsub client) throws IOException {
    String fullName = String.format("projects/%s/topics/%s",
            PubsubUtils.getProjectId(),
            PubsubUtils.getAppTopicName());

    try {
        client.projects().topics().get(fullName).execute();
    } catch (GoogleJsonResponseException e) {
        if (e.getStatusCode() == HttpStatusCodes.STATUS_CODE_NOT_FOUND) {
            // Create the topic if it doesn't exist
            client.projects().topics()
                    .create(fullName, new Topic())
                    .execute();
        } else {
            throw e;
        }
    }
}
 

@Override
public final void doGet(final HttpServletRequest req,
                        final HttpServletResponse resp)
        throws IOException {
    Pubsub client = PubsubUtils.getClient();
    String projectId = PubsubUtils.getProjectId();
    req.setAttribute("project", projectId);

    setupTopic(client);
    setupSubscription(client);

    req.setAttribute("topic", PubsubUtils.getAppTopicName());
    req.setAttribute("subscription", PubsubUtils.getAppSubscriptionName());
    req.setAttribute("subscriptionEndpoint",
            PubsubUtils.getAppEndpointUrl()
                    .replaceAll("token=[^&]*", "token=REDACTED"));
    RequestDispatcher rd = req.getRequestDispatcher("/WEB-INF/main.jsp");
    try {
        rd.forward(req, resp);
    } catch (ServletException e) {
        throw new IOException(e);
    }
}
 

@Override
public final void doPost(final HttpServletRequest req,
                         final HttpServletResponse resp)
        throws IOException {
    Pubsub client = PubsubUtils.getClient();
    String message = req.getParameter("message");
    if (!"".equals(message)) {
        String fullTopicName = String.format("projects/%s/topics/%s",
                PubsubUtils.getProjectId(),
                PubsubUtils.getAppTopicName());
        PubsubMessage pubsubMessage = new PubsubMessage();
        pubsubMessage.encodeData(message.getBytes("UTF-8"));
        PublishRequest publishRequest = new PublishRequest();
        publishRequest.setMessages(ImmutableList.of(pubsubMessage));

        client.projects().topics()
                .publish(fullTopicName, publishRequest)
                .execute();
    }
    resp.setStatus(HttpServletResponse.SC_NO_CONTENT);
    resp.getWriter().close();
}
 

/**
 * Constructor that will automatically instantiate a Google Cloud Pub/Sub instance.
 *
 * @throws IOException when the initialization of the Google Cloud Pub/Sub client fails.
 */
public GcloudPubsub() throws IOException {
  if (CLOUD_PUBSUB_PROJECT_ID == null) {
    throw new IllegalStateException(GCLOUD_PUBSUB_PROJECT_ID_NOT_SET_ERROR);
  }
  try {
    serverName = InetAddress.getLocalHost().getCanonicalHostName();
  } catch (UnknownHostException e) {
    throw new IllegalStateException("Unable to retrieve the hostname of the system");
  }
  HttpTransport httpTransport = checkNotNull(Utils.getDefaultTransport());
  JsonFactory jsonFactory = checkNotNull(Utils.getDefaultJsonFactory());
  GoogleCredential credential = GoogleCredential.getApplicationDefault(
      httpTransport, jsonFactory);
  if (credential.createScopedRequired()) {
    credential = credential.createScoped(PubsubScopes.all());
  }
  HttpRequestInitializer initializer =
      new RetryHttpInitializerWrapper(credential);
  pubsub = new Pubsub.Builder(httpTransport, jsonFactory, initializer).build();
  logger.info("Google Cloud Pub/Sub Initialization SUCCESS");
}
 

public PubSubClient(PubSubDatastoreProperties datastore, boolean runOnDataflow) {

        Credentials credentials = null;
        if (runOnDataflow || datastore.serviceAccountFile.getValue() == null) {
            try {
                credentials = GoogleCredentials.getApplicationDefault().createScoped(PubsubScopes.all());
            } catch (IOException e) {
                throw TalendRuntimeException.createUnexpectedException(e);
            }
        } else {
            credentials = createCredentials(datastore);
        }
        this.PROJECT_NAME = datastore.projectName.getValue();
        this.client = new Pubsub.Builder(Transport.getTransport(), Transport.getJsonFactory(),
                chainHttpRequestInitializer(credentials,
                        // Do not log 404. It clutters the output and is possibly even required by the caller.
                        new RetryHttpRequestInitializer(ImmutableList.of(404)))).build();
    }
 

/**
 * Builds a new Pubsub client and returns it.
 *
 * @param httpTransport HttpTransport for Pubsub client.
 * @param jsonFactory JsonFactory for Pubsub client.
 * @return Pubsub client.
 * @throws IOException when we can not get the default credentials.
 */
public static Pubsub getClient(final HttpTransport httpTransport,
                               final JsonFactory jsonFactory)
         throws IOException {
    Preconditions.checkNotNull(httpTransport);
    Preconditions.checkNotNull(jsonFactory);
    GoogleCredential credential =
        GoogleCredential.getApplicationDefault(httpTransport, jsonFactory);
    if (credential.createScopedRequired()) {
        credential = credential.createScoped(PubsubScopes.all());
    }
    // Please use custom HttpRequestInitializer for automatic
    // retry upon failures.
    HttpRequestInitializer initializer =
        new RetryHttpInitializerWrapper(credential);
    return new Pubsub.Builder(httpTransport, jsonFactory, initializer)
            .setApplicationName(APP_NAME)
            .build();
}
 

/**
 * Lists existing topics in the project.
 *
 * @param client Cloud Pub/Sub client.
 * @param args Command line arguments.
 * @throws IOException when Cloud Pub/Sub API calls fail.
 */
public static void listTopics(final Pubsub client, final String[] args)
        throws IOException {
    String nextPageToken = null;
    boolean hasTopics = false;
    Pubsub.Projects.Topics.List listMethod =
            client.projects().topics().list("projects/" + args[0]);
    do {
        if (nextPageToken != null) {
            listMethod.setPageToken(nextPageToken);
        }
        ListTopicsResponse response = listMethod.execute();
        if (!response.isEmpty()) {
            for (Topic topic : response.getTopics()) {
                hasTopics = true;
                System.out.println(topic.getName());
            }
        }
        nextPageToken = response.getNextPageToken();
    } while (nextPageToken != null);
    if (!hasTopics) {
        System.out.println(String.format(
                "There are no topics in the project '%s'.", args[0]));
    }
}
 

/**
 * Publishes the given message to the given topic.
 *
 * @param client Cloud Pub/Sub client.
 * @param args Command line arguments.
 * @throws IOException when Cloud Pub/Sub API calls fail.
 */
public static void publishMessage(final Pubsub client, final String[] args)
        throws IOException {
    Main.checkArgsLength(args, 4);
    String topic = PubsubUtils.getFullyQualifiedResourceName(
            PubsubUtils.ResourceType.TOPIC, args[0], args[2]);
    String message = args[3];
    PubsubMessage pubsubMessage = new PubsubMessage()
            .encodeData(message.getBytes("UTF-8"));
    List<PubsubMessage> messages = ImmutableList.of(pubsubMessage);
    PublishRequest publishRequest = new PublishRequest();
    publishRequest.setMessages(messages);
    PublishResponse publishResponse = client.projects().topics()
            .publish(topic, publishRequest)
            .execute();
    List<String> messageIds = publishResponse.getMessageIds();
    if (messageIds != null) {
        for (String messageId : messageIds) {
            System.out.println("Published with a message id: " + messageId);
        }
    }
}
 

/**
 * Creates a new 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 createSubscription(final Pubsub client,
                                      final String[] args)
        throws IOException {
    Main.checkArgsLength(args, 4);
    String subscriptionName = PubsubUtils.getFullyQualifiedResourceName(
            PubsubUtils.ResourceType.SUBSCRIPTION, args[0], args[2]);
    Subscription subscription = new Subscription()
            .setTopic(PubsubUtils.getFullyQualifiedResourceName(
                    PubsubUtils.ResourceType.TOPIC, args[0], args[3]));
    if (args.length == 5) {
        subscription = subscription.setPushConfig(
            new PushConfig().setPushEndpoint(args[4]));
    }
    subscription = client.projects().subscriptions()
            .create(subscriptionName, subscription)
            .execute();
    System.out.printf(
            "Subscription %s was created.\n", subscription.getName());
    System.out.println(subscription.toPrettyString());
}
 

public static Pubsub createPubsubClient(String serviceAccountEmail, String privateKeyFilePath)
    throws IOException, GeneralSecurityException {
  HttpTransport transport = GoogleNetHttpTransport.newTrustedTransport();
  GoogleCredential credential = new GoogleCredential.Builder()
      .setTransport(transport)
      .setJsonFactory(JSON_FACTORY)
      .setServiceAccountScopes(PubsubScopes.all())

      // Obtain this from the "APIs & auth" -> "Credentials"
      // section in the Google Developers Console:
      // https://console.developers.google.com/
      // (and put the e-mail address into your system property obviously)
      .setServiceAccountId(serviceAccountEmail)

      // Download this file from "APIs & auth" -> "Credentials"
      // section in the Google Developers Console:
      // https://console.developers.google.com/
      .setServiceAccountPrivateKeyFromP12File(new File(privateKeyFilePath))
      .build();


  // Please use custom HttpRequestInitializer for automatic
  // retry upon failures.  We provide a simple reference
  // implementation in the "Retry Handling" section.
  HttpRequestInitializer initializer =
      new RetryHttpInitializerWrapper(credential);
  return new Pubsub.Builder(transport, JSON_FACTORY, initializer)
      .setApplicationName("PubSub Example")
      .build();
}
 

/** Returns a LocalController using default application credentials. */
public static LocalController newLocalController(
    String projectName, Map<ClientParams, Integer> clients, ScheduledExecutorService executor) {
  try {
    HttpTransport transport = GoogleNetHttpTransport.newTrustedTransport();
    JsonFactory jsonFactory = new JacksonFactory();
    GoogleCredential credential = GoogleCredential.getApplicationDefault(transport, jsonFactory);
    if (credential.createScopedRequired()) {
      credential =
          credential.createScoped(
              Collections.singletonList("https://www.googleapis.com/auth/cloud-platform"));
    }
    Pubsub pubsub =
        new Pubsub.Builder(transport, jsonFactory, credential)
            .setApplicationName("Cloud Pub/Sub Loadtest Framework")
            .build();
    ArrayList<ResourceController> controllers = new ArrayList<>();
    ArrayList<ComputeResourceController> computeControllers = new ArrayList<>();
    clients.forEach(
        (params, numWorkers) -> {
          ComputeResourceController computeController =
              new LocalComputeResourceController(params, numWorkers, executor);
          controllers.add(computeController);
          computeControllers.add(computeController);
        });
    controllers.add(
        new PubsubResourceController(
            projectName, Client.TOPIC, ImmutableList.of(Client.SUBSCRIPTION), executor, pubsub));
    return new LocalController(executor, controllers, computeControllers);
  } catch (Throwable t) {
    log.error("Unable to initialize GCE: ", t);
    return null;
  }
}
 

PubsubPublisher(Context context, String appname, String project, String topic,
                int credentialResourceId) throws IOException {
    mContext = context;
    mAppname = appname;
    mTopic = "projects/" + project + "/topics/" + topic;

    mHandlerThread = new HandlerThread("pubsubPublisherThread");
    mHandlerThread.start();
    mHandler = new Handler(mHandlerThread.getLooper());

    InputStream jsonCredentials = mContext.getResources().openRawResource(credentialResourceId);
    final GoogleCredential credentials;
    try {
        credentials = GoogleCredential.fromStream(jsonCredentials).createScoped(
                Collections.singleton(PubsubScopes.PUBSUB));
    } finally {
        try {
            jsonCredentials.close();
        } catch (IOException e) {
            Log.e(TAG, "Error closing input stream", e);
        }
    }
    mHandler.post(new Runnable() {
        @Override
        public void run() {
            mHttpTransport = AndroidHttp.newCompatibleTransport();
            JsonFactory jsonFactory = JacksonFactory.getDefaultInstance();
            mPubsub = new Pubsub.Builder(mHttpTransport, jsonFactory, credentials)
                    .setApplicationName(mAppname).build();
        }
    });
}
 

public PubsubResourceController(
    String project,
    String topic,
    List<String> subscriptions,
    ScheduledExecutorService executor,
    Pubsub pubsub) {
  super(executor);
  this.project = project;
  this.topic = topic;
  this.subscriptions = subscriptions;
  this.pubsub = pubsub;
}
 

/**
 * Creates a Cloud Pub/Sub subscription if it doesn't exist.
 *
 * @param client Pubsub client object.
 * @throws IOException when API calls to Cloud Pub/Sub fails.
 */
private void setupSubscription(final Pubsub client) throws IOException {
    String fullName = String.format("projects/%s/subscriptions/%s",
            PubsubUtils.getProjectId(),
            PubsubUtils.getAppSubscriptionName());

    try {
        client.projects().subscriptions().get(fullName).execute();
    } catch (GoogleJsonResponseException e) {
        if (e.getStatusCode() == HttpStatusCodes.STATUS_CODE_NOT_FOUND) {
            // Create the subscription if it doesn't exist
            String fullTopicName = String.format("projects/%s/topics/%s",
                    PubsubUtils.getProjectId(),
                    PubsubUtils.getAppTopicName());
            PushConfig pushConfig = new PushConfig()
                    .setPushEndpoint(PubsubUtils.getAppEndpointUrl());
            Subscription subscription = new Subscription()
                    .setTopic(fullTopicName)
                    .setPushConfig(pushConfig);
            client.projects().subscriptions()
                    .create(fullName, subscription)
                    .execute();
        } else {
            throw e;
        }
    }
}
 

/**
 * Creates a Cloud Pub/Sub client.
 */
public Pubsub createPubsubClient()
  throws IOException, GeneralSecurityException {
  HttpTransport transport = GoogleNetHttpTransport.newTrustedTransport();
  GoogleCredential credential = GoogleCredential.getApplicationDefault();
  HttpRequestInitializer initializer =
      new RetryHttpInitializerWrapper(credential);
  return new Pubsub.Builder(transport, JSON_FACTORY, initializer).build();
}
 

/**
 * Fetches news and publishes them to the specified Cloud Pub/Sub topic.
 */
public static void main(String[] args) throws Exception {
  // Get options from command-line.
  if (args.length < 1) {
    System.out.println("Please specify the output Pubsub topic.");
    return;
  }

  String newsTopic = new String(args[0]);

  System.out.println("Output Pubsub topic: " + newsTopic);

  NewsInjector injector = new NewsInjector(null, "");
  // Create a Pubsub.
  Pubsub client = injector.createPubsubClient();

  injector = new NewsInjector(client, newsTopic);

  while (true) {
    // Fetch news.
    injector.publishNews();

    try {
      //thread to sleep for the specified number of milliseconds
      Thread.sleep(20000);
    } catch ( java.lang.InterruptedException ie) {
      ;
    }
  }
}
 

/**
 * Creates a Cloud Pub/Sub client.
 */
public Pubsub createPubsubClient()
  throws IOException, GeneralSecurityException {
  HttpTransport transport = GoogleNetHttpTransport.newTrustedTransport();
  GoogleCredential credential = GoogleCredential.getApplicationDefault();
  HttpRequestInitializer initializer =
      new RetryHttpInitializerWrapper(credential);
  return new Pubsub.Builder(transport, JSON_FACTORY, initializer).build();
}
 

/** Returns a Pubsub client builder using the specified {@link PubsubOptions}. */
private static Pubsub.Builder newPubsubClient(PubsubOptions options) {
  return new Pubsub.Builder(
          Transport.getTransport(),
          Transport.getJsonFactory(),
          chainHttpRequestInitializer(
              options.getGcpCredential(),
              // Do not log 404. It clutters the output and is possibly even required by the
              // caller.
              new RetryHttpRequestInitializer(ImmutableList.of(404))))
      .setRootUrl(options.getPubsubRootUrl())
      .setApplicationName(options.getAppName())
      .setGoogleClientRequestInitializer(options.getGoogleApiTrace());
}
 

/**
 * Deletes a topic with the given name.
 *
 * @param client Cloud Pub/Sub client.
 * @param args Command line arguments.
 * @throws IOException when Cloud Pub/Sub API calls fail.
 */
public static void deleteTopic(final Pubsub client, final String[] args)
        throws IOException {
    Main.checkArgsLength(args, 3);
    String topicName = PubsubUtils.getFullyQualifiedResourceName(
            PubsubUtils.ResourceType.TOPIC, args[0], args[2]);
    client.projects().topics().delete(topicName).execute();
    System.out.printf("Topic %s was deleted.\n", topicName);
}
 

/** Create a topic if it doesn't exist. */
public static void createTopic(Pubsub client, String fullTopicName) throws IOException {
  System.out.println("fullTopicName " + fullTopicName);
  try {
    client.projects().topics().get(fullTopicName).execute();
  } catch (GoogleJsonResponseException e) {
    if (e.getStatusCode() == HttpStatusCodes.STATUS_CODE_NOT_FOUND) {
      Topic topic = client.projects().topics().create(fullTopicName, new Topic()).execute();
      System.out.printf("Topic %s was created.%n", topic.getName());
    }
  }
}
 

/**
 * Creates a new topic with a given name.
 *
 * @param client Cloud Pub/Sub client.
 * @param args Command line arguments.
 * @throws IOException when Cloud Pub/Sub API calls fail.
 */
public static void createTopic(final Pubsub client, final String[] args)
        throws IOException {
    Main.checkArgsLength(args, 3);
    String topicName = PubsubUtils.getFullyQualifiedResourceName(
            PubsubUtils.ResourceType.TOPIC, args[0], args[2]);
    Topic topic = client.projects().topics()
            .create(topicName, new Topic())
            .execute();
    System.out.printf("Topic %s was created.\n", topic.getName());
}
 

/**
 * Deletes a subscription with a given name.
 *
 * @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 deleteSubscription(final Pubsub client,
                                      final String[] args)
        throws IOException {
    Main.checkArgsLength(args, 3);
    String subscriptionName = PubsubUtils.getFullyQualifiedResourceName(
            PubsubUtils.ResourceType.SUBSCRIPTION, args[0], args[2]);
    client.projects().subscriptions().delete(subscriptionName).execute();
    System.out.printf("Subscription %s was deleted.\n", subscriptionName);
}
 

/**
 * 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);
}
 

/**
 * Lists existing subscriptions within a project.
 *
 * @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 listSubscriptions(final Pubsub client,
                                     final String[] args)
        throws IOException {
    String nextPageToken = null;
    boolean hasSubscriptions = false;
    Pubsub.Projects.Subscriptions.List listMethod =
            client.projects().subscriptions().list("projects/" + args[0]);
    do {
        if (nextPageToken != null) {
            listMethod.setPageToken(nextPageToken);
        }
        ListSubscriptionsResponse response = listMethod.execute();
        if (!response.isEmpty()) {
            for (Subscription subscription : response.getSubscriptions()) {
                hasSubscriptions = true;
                System.out.println(subscription.toPrettyString());
            }
        }
        nextPageToken = response.getNextPageToken();
    } while (nextPageToken != null);
    if (!hasSubscriptions) {
        System.out.println(String.format(
                "There are no subscriptions in the project '%s'.",
                args[0]));
    }
}
 

/**
 * Creates a topic <code>/projects/</code>appName<code>/topics/</code>topicName if it does not already exist.
 */
Topic createTopic(String topicName) throws IOException {
    String topic = getTopic(topicName);
    Pubsub.Projects.Topics topics = pubsub.projects().topics();
    ListTopicsResponse list = topics.list(project).execute();
    if (list.getTopics() == null || !list.getTopics().contains(new Topic().setName(topic))) {
        return topics.create(topic, new Topic()).execute();
    } else {
        return new Topic().setName(topic);
    }
}