Examples with State utilities.State used on opensource projects

Example 1 with State

use of utilities.State in project java-pubsub by googleapis.

the class SubscribeWithAvroSchemaExample method subscribeWithAvroSchemaExample.

public static void subscribeWithAvroSchemaExample(String projectId, String subscriptionId) {
    ProjectSubscriptionName subscriptionName = ProjectSubscriptionName.of(projectId, subscriptionId);
    // Prepare a reader for the encoded Avro records.
    SpecificDatumReader<State> reader = new SpecificDatumReader<>(State.getClassSchema());
    // Instantiate an asynchronous message receiver.
    MessageReceiver receiver = (PubsubMessage message, AckReplyConsumer consumer) -> {
        ByteString data = message.getData();
        // Get the schema encoding type.
        String encoding = message.getAttributesMap().get("googclient_schemaencoding");
        // Send the message data to a byte[] input stream.
        InputStream inputStream = new ByteArrayInputStream(data.toByteArray());
        Decoder decoder = null;
        // based on the schema encoding type.
        block: try {
            switch(encoding) {
                case "BINARY":
                    decoder = DecoderFactory.get().directBinaryDecoder(inputStream, /*reuse=*/
                    null);
                    System.out.println("Receiving a binary-encoded message:");
                    break;
                case "JSON":
                    decoder = DecoderFactory.get().jsonDecoder(State.getClassSchema(), inputStream);
                    System.out.println("Receiving a JSON-encoded message:");
                    break;
                default:
                    break block;
            }
            // Obtain an object of the generated Avro class using the decoder.
            State state = reader.read(null, decoder);
            System.out.println(state.getName() + " is abbreviated as " + state.getPostAbbr());
        } catch (IOException e) {
            System.err.println(e);
        }
        // Ack the message.
        consumer.ack();
    };
    Subscriber subscriber = null;
    try {
        subscriber = Subscriber.newBuilder(subscriptionName, receiver).build();
        subscriber.startAsync().awaitRunning();
        System.out.printf("Listening for messages on %s:\n", subscriptionName.toString());
        subscriber.awaitTerminated(30, TimeUnit.SECONDS);
    } catch (TimeoutException timeoutException) {
        subscriber.stopAsync();
    }
}

Example 2 with State

use of utilities.State in project java-pubsub by googleapis.

the class PublishAvroRecordsExample method publishAvroRecordsExample.

public static void publishAvroRecordsExample(String projectId, String topicId) throws IOException, ExecutionException, InterruptedException {
    Encoding encoding = null;
    TopicName topicName = TopicName.of(projectId, topicId);
    // Get the topic encoding type.
    try (TopicAdminClient topicAdminClient = TopicAdminClient.create()) {
        encoding = topicAdminClient.getTopic(topicName).getSchemaSettings().getEncoding();
    }
    // Instantiate an avro-tools-generated class defined in `us-states.avsc`.
    State state = State.newBuilder().setName("Alaska").setPostAbbr("AK").build();
    Publisher publisher = null;
    block: try {
        publisher = Publisher.newBuilder(topicName).build();
        // Prepare to serialize the object to the output stream.
        ByteArrayOutputStream byteStream = new ByteArrayOutputStream();
        Encoder encoder = null;
        // Prepare an appropriate encoder for publishing to the topic.
        switch(encoding) {
            case BINARY:
                System.out.println("Preparing a BINARY encoder...");
                encoder = EncoderFactory.get().directBinaryEncoder(byteStream, /*reuse=*/
                null);
                break;
            case JSON:
                System.out.println("Preparing a JSON encoder...");
                encoder = EncoderFactory.get().jsonEncoder(State.getClassSchema(), byteStream);
                break;
            default:
                break block;
        }
        // Encode the object and write it to the output stream.
        state.customEncode(encoder);
        encoder.flush();
        // Publish the encoded object as a Pub/Sub message.
        ByteString data = ByteString.copyFrom(byteStream.toByteArray());
        PubsubMessage message = PubsubMessage.newBuilder().setData(data).build();
        System.out.println("Publishing message: " + message);
        ApiFuture<String> future = publisher.publish(message);
        System.out.println("Published message ID: " + future.get());
    } finally {
        if (publisher != null) {
            publisher.shutdown();
            publisher.awaitTermination(1, TimeUnit.MINUTES);
        }
    }
}