Java 类com.amazonaws.services.kinesis.model.DescribeStreamRequest 实例源码

private void refreshShards() {
  DescribeStreamRequest describeStreamRequest = new DescribeStreamRequest();
  describeStreamRequest.setStreamName(streamName);
  String exclusiveStartShardId = null;
  List<Shard> shards = new ArrayList<>();

  do {
    describeStreamRequest.setExclusiveStartShardId(exclusiveStartShardId);
    DescribeStreamResult describeStreamResult = kinesisClient.describeStream(describeStreamRequest);
    shards.addAll(describeStreamResult.getStreamDescription().getShards());

    if (describeStreamResult.getStreamDescription().getHasMoreShards() && shards.size() > 0) {
      exclusiveStartShardId = shards.get(shards.size() - 1).getShardId();
    } else {
      exclusiveStartShardId = null;
    }
  } while (exclusiveStartShardId != null);

  this.shards = shards;
}

@Test
public void testProvisionProducerSuccessfulWithExistingStream() {
    AmazonKinesis amazonKinesisMock = mock(AmazonKinesis.class);
    KinesisBinderConfigurationProperties binderProperties = new KinesisBinderConfigurationProperties();
    KinesisStreamProvisioner provisioner = new KinesisStreamProvisioner(amazonKinesisMock, binderProperties);
    ExtendedProducerProperties<KinesisProducerProperties> extendedProducerProperties =
            new ExtendedProducerProperties<>(new KinesisProducerProperties());
    String name = "test-stream";

    DescribeStreamResult describeStreamResult = describeStreamResultWithShards(
            Collections.singletonList(new Shard()));

    when(amazonKinesisMock.describeStream(any(DescribeStreamRequest.class)))
            .thenReturn(describeStreamResult);

    ProducerDestination destination = provisioner.provisionProducerDestination(name, extendedProducerProperties);

    verify(amazonKinesisMock)
            .describeStream(any(DescribeStreamRequest.class));

    assertThat(destination.getName()).isEqualTo(name);
}

@Test
public void testProvisionConsumerSuccessfulWithExistingStream() {
    AmazonKinesis amazonKinesisMock = mock(AmazonKinesis.class);
    KinesisBinderConfigurationProperties binderProperties = new KinesisBinderConfigurationProperties();
    KinesisStreamProvisioner provisioner = new KinesisStreamProvisioner(amazonKinesisMock, binderProperties);

    ExtendedConsumerProperties<KinesisConsumerProperties> extendedConsumerProperties =
            new ExtendedConsumerProperties<>(new KinesisConsumerProperties());

    String name = "test-stream";
    String group = "test-group";

    DescribeStreamResult describeStreamResult =
            describeStreamResultWithShards(Collections.singletonList(new Shard()));

    when(amazonKinesisMock.describeStream(any(DescribeStreamRequest.class)))
            .thenReturn(describeStreamResult);

    ConsumerDestination destination =
            provisioner.provisionConsumerDestination(name, group, extendedConsumerProperties);

    verify(amazonKinesisMock)
            .describeStream(any(DescribeStreamRequest.class));

    assertThat(destination.getName()).isEqualTo(name);
}

@Before
public void setup() throws Exception {
    KinesisEndpoint endpoint = new KinesisEndpoint(null, "streamName", component);
    endpoint.setAmazonKinesisClient(kinesisClient);
    endpoint.setIteratorType(ShardIteratorType.LATEST);
    undertest = new KinesisConsumer(endpoint, processor);

    when(kinesisClient.getRecords(any(GetRecordsRequest.class)))
        .thenReturn(new GetRecordsResult()
            .withNextShardIterator("nextShardIterator")
        );
    when(kinesisClient.describeStream(any(DescribeStreamRequest.class)))
        .thenReturn(new DescribeStreamResult()
            .withStreamDescription(new StreamDescription()
                .withShards(new Shard().withShardId("shardId"))
            )
        );
    when(kinesisClient.getShardIterator(any(GetShardIteratorRequest.class)))
        .thenReturn(new GetShardIteratorResult()
            .withShardIterator("shardIterator")
        );
}

@Test
public void itObtainsAShardIteratorOnFirstPollForSequenceNumber() throws Exception {
    undertest.getEndpoint().setSequenceNumber("12345");
    undertest.getEndpoint().setIteratorType(ShardIteratorType.AFTER_SEQUENCE_NUMBER);

    undertest.poll();

    final ArgumentCaptor<DescribeStreamRequest> describeStreamReqCap = ArgumentCaptor.forClass(DescribeStreamRequest.class);
    final ArgumentCaptor<GetShardIteratorRequest> getShardIteratorReqCap = ArgumentCaptor.forClass(GetShardIteratorRequest.class);

    verify(kinesisClient).describeStream(describeStreamReqCap.capture());
    assertThat(describeStreamReqCap.getValue().getStreamName(), is("streamName"));

    verify(kinesisClient).getShardIterator(getShardIteratorReqCap.capture());
    assertThat(getShardIteratorReqCap.getValue().getStreamName(), is("streamName"));
    assertThat(getShardIteratorReqCap.getValue().getShardId(), is("shardId"));
    assertThat(getShardIteratorReqCap.getValue().getShardIteratorType(), is("AFTER_SEQUENCE_NUMBER"));
    assertThat(getShardIteratorReqCap.getValue().getStartingSequenceNumber(), is("12345"));

}

/**
 * Create the specified topic with the specified number of partitions
 */
public void createTopic(String topicName, int partitions) {
    LOGGER.info("Determining if  Kinesis topic: {} already exists...", topicName);
    try{
        final DescribeStreamRequest describeRequest = new DescribeStreamRequest();
        describeRequest.withStreamName(topicName);
        this.client.describeStream(describeRequest);

    }catch(ResourceNotFoundException rnf){
        LOGGER.info("Kinesis stream for topic: {} does not exist, creating now with shard count: {}",topicName, partitions);
        final CreateStreamRequest request = new CreateStreamRequest();
        request.withStreamName(topicName);
        request.withShardCount(partitions);
        this.client.createStream(request);
        this.waitForStreamToBecomeAvailable(topicName, DEFAULT_WAIT_TIME_MINUTES);
        LOGGER.info("Create topic completed for topic: {}", topicName);
    }    
}

private static void waitForStreamToBecomeAvailable(String myStreamName) throws InterruptedException {
    LOG.info("Waiting for " + myStreamName + " to become ACTIVE...");

    long startTime = System.currentTimeMillis();
    long endTime = startTime + TimeUnit.MINUTES.toMillis(5);
    while (System.currentTimeMillis() < endTime) {
        Thread.sleep( TimeUnit.SECONDS.toMillis(5));
        DescribeStreamRequest describeStreamRequest = new DescribeStreamRequest();
        describeStreamRequest.setStreamName(myStreamName);
        describeStreamRequest.setLimit(10);
        DescribeStreamResult describeStreamResponse = kinesisClient
                .describeStream(describeStreamRequest);

        String streamStatus = describeStreamResponse
                .getStreamDescription().getStreamStatus();
        if ("ACTIVE".equals(streamStatus)) {
            return;
        }
    }
}

private List<Shard> describeStream(String stream) {
    AmazonKinesisAsync amazonKinesis = localKinesisResource.getResource();

    String exclusiveStartShardId = null;

    DescribeStreamRequest describeStreamRequest = new DescribeStreamRequest()
            .withStreamName(stream);

    List<Shard> shardList = new ArrayList<>();

    while (true) {
        DescribeStreamResult describeStreamResult = null;

        describeStreamRequest.withExclusiveStartShardId(exclusiveStartShardId);
        describeStreamResult = amazonKinesis.describeStream(describeStreamRequest);
        StreamDescription streamDescription = describeStreamResult.getStreamDescription();
        if (StreamStatus.ACTIVE.toString().equals(streamDescription.getStreamStatus())) {
            shardList.addAll(streamDescription.getShards());

            if (streamDescription.getHasMoreShards()) {
                exclusiveStartShardId = shardList.get(shardList.size() - 1).getShardId();
                continue;
            }
            else {
                return shardList;
            }
        }
        try {
            Thread.sleep(100);
        }
        catch (InterruptedException e) {
            Thread.currentThread().interrupt();
            throw new IllegalStateException(e);
        }
    }
}

@Test
public void testProvisionConsumerExistingStreamUpdateShards() {
    AmazonKinesis amazonKinesisMock = mock(AmazonKinesis.class);
    ArgumentCaptor<UpdateShardCountRequest> updateShardCaptor =
            ArgumentCaptor.forClass(UpdateShardCountRequest.class);
    String name = "test-stream";
    String group = "test-group";
    int targetShardCount = 2;
    KinesisBinderConfigurationProperties binderProperties = new KinesisBinderConfigurationProperties();
    binderProperties.setMinShardCount(targetShardCount);
    binderProperties.setAutoAddShards(true);
    KinesisStreamProvisioner provisioner = new KinesisStreamProvisioner(amazonKinesisMock, binderProperties);

    ExtendedConsumerProperties<KinesisConsumerProperties> extendedConsumerProperties =
            new ExtendedConsumerProperties<>(new KinesisConsumerProperties());

    DescribeStreamResult describeOriginalStream =
            describeStreamResultWithShards(Collections.singletonList(new Shard()));

    DescribeStreamResult describeUpdatedStream =
            describeStreamResultWithShards(Arrays.asList(new Shard(), new Shard()));

    when(amazonKinesisMock.describeStream(any(DescribeStreamRequest.class)))
            .thenReturn(describeOriginalStream)
            .thenReturn(describeUpdatedStream);

    provisioner.provisionConsumerDestination(name, group, extendedConsumerProperties);

    verify(amazonKinesisMock, times(1))
            .updateShardCount(updateShardCaptor.capture());

    assertThat(updateShardCaptor.getValue().getStreamName()).isEqualTo(name);
    assertThat(updateShardCaptor.getValue().getScalingType()).isEqualTo(ScalingType.UNIFORM_SCALING.name());
    assertThat(updateShardCaptor.getValue().getTargetShardCount()).isEqualTo(targetShardCount);
}

@Test
public void testProvisionProducerSuccessfulWithNewStream() {
    AmazonKinesis amazonKinesisMock = mock(AmazonKinesis.class);
    KinesisBinderConfigurationProperties binderProperties = new KinesisBinderConfigurationProperties();
    KinesisStreamProvisioner provisioner = new KinesisStreamProvisioner(amazonKinesisMock, binderProperties);
    ExtendedProducerProperties<KinesisProducerProperties> extendedProducerProperties =
            new ExtendedProducerProperties<>(new KinesisProducerProperties());

    String name = "test-stream";
    Integer shards = 1;

    DescribeStreamResult describeStreamResult =
            describeStreamResultWithShards(Collections.singletonList(new Shard()));

    when(amazonKinesisMock.describeStream(any(DescribeStreamRequest.class)))
            .thenThrow(new ResourceNotFoundException("I got nothing"))
            .thenReturn(describeStreamResult);

    when(amazonKinesisMock.createStream(name, shards))
            .thenReturn(new CreateStreamResult());

    ProducerDestination destination = provisioner.provisionProducerDestination(name, extendedProducerProperties);

    verify(amazonKinesisMock, times(2))
            .describeStream(any(DescribeStreamRequest.class));

    verify(amazonKinesisMock)
            .createStream(name, shards);

    assertThat(destination.getName()).isEqualTo(name);
}

@Test
public void testProvisionProducerUpdateShards() {
    AmazonKinesis amazonKinesisMock = mock(AmazonKinesis.class);
    ArgumentCaptor<UpdateShardCountRequest> updateShardCaptor = ArgumentCaptor.forClass(UpdateShardCountRequest.class);
    String name = "test-stream";
    String group = "test-group";
    int targetShardCount = 2;
    KinesisBinderConfigurationProperties binderProperties = new KinesisBinderConfigurationProperties();
    binderProperties.setMinShardCount(targetShardCount);
    binderProperties.setAutoAddShards(true);
    KinesisStreamProvisioner provisioner = new KinesisStreamProvisioner(amazonKinesisMock, binderProperties);

    ExtendedConsumerProperties<KinesisConsumerProperties> extendedConsumerProperties =
            new ExtendedConsumerProperties<>(new KinesisConsumerProperties());

    DescribeStreamResult describeOriginalStream =
            describeStreamResultWithShards(Collections.singletonList(new Shard()));

    DescribeStreamResult describeUpdatedStream =
            describeStreamResultWithShards(Arrays.asList(new Shard(), new Shard()));

    when(amazonKinesisMock.describeStream(any(DescribeStreamRequest.class)))
            .thenReturn(describeOriginalStream)
            .thenReturn(describeUpdatedStream);

    provisioner.provisionConsumerDestination(name, group, extendedConsumerProperties);

    verify(amazonKinesisMock, times(1))
            .updateShardCount(updateShardCaptor.capture());
    assertThat(updateShardCaptor.getValue().getStreamName()).isEqualTo(name);
    assertThat(updateShardCaptor.getValue().getScalingType()).isEqualTo(ScalingType.UNIFORM_SCALING.name());
    assertThat(updateShardCaptor.getValue().getTargetShardCount()).isEqualTo(targetShardCount);
}

@Test
public void testProvisionConsumerSuccessfulWithNewStream() {
    AmazonKinesis amazonKinesisMock = mock(AmazonKinesis.class);
    KinesisBinderConfigurationProperties binderProperties = new KinesisBinderConfigurationProperties();
    KinesisStreamProvisioner provisioner = new KinesisStreamProvisioner(amazonKinesisMock, binderProperties);
    int instanceCount = 1;
    int concurrency = 1;

    ExtendedConsumerProperties<KinesisConsumerProperties> extendedConsumerProperties =
            new ExtendedConsumerProperties<>(new KinesisConsumerProperties());
    extendedConsumerProperties.setInstanceCount(instanceCount);
    extendedConsumerProperties.setConcurrency(concurrency);

    String name = "test-stream";
    String group = "test-group";

    DescribeStreamResult describeStreamResult =
            describeStreamResultWithShards(Collections.singletonList(new Shard()));


    when(amazonKinesisMock.describeStream(any(DescribeStreamRequest.class)))
            .thenThrow(new ResourceNotFoundException("I got nothing"))
            .thenReturn(describeStreamResult);

    when(amazonKinesisMock.createStream(name, instanceCount * concurrency))
            .thenReturn(new CreateStreamResult());

    ConsumerDestination destination = provisioner.provisionConsumerDestination(name, group,
            extendedConsumerProperties);

    verify(amazonKinesisMock, times(2))
            .describeStream(any(DescribeStreamRequest.class));

    verify(amazonKinesisMock)
            .createStream(name, instanceCount * concurrency);

    assertThat(destination.getName()).isEqualTo(name);
}

@Override
public void start(Map<String, String> settings) {
  log.info("start()");
  this.settings = settings;
  this.config = new KinesisSourceConnectorConfig(settings);
  this.kinesisClient = this.kinesisClientFactory.create(this.config);

  DescribeStreamRequest describeStreamRequest = new DescribeStreamRequest()
      .withStreamName(this.config.kinesisStreamName);

  DescribeStreamResult describeStreamResult = this.kinesisClient.describeStream(describeStreamRequest);
  this.streamDescription = describeStreamResult.getStreamDescription();
}

@Test
public void start() {
  final DescribeStreamRequest expectedDescribeStreamRequest = new DescribeStreamRequest()
      .withStreamName(TestData.EXPECTED_STREAM_NAME);

  final int SHARD_COUNT = 50;
  List<Shard> shards = new ArrayList<>(SHARD_COUNT);
  for (int i = 0; i < SHARD_COUNT; i++) {
    String shardId = String.format("%03d", i);
    final Shard shard = new Shard()
        .withShardId(shardId);
    shards.add(shard);
  }


  final StreamDescription streamDescription = new StreamDescription()
      .withStreamName(TestData.EXPECTED_STREAM_NAME)
      .withShards(shards);

  final DescribeStreamResult expectedStreamRequest = new DescribeStreamResult()
      .withStreamDescription(streamDescription);

  when(this.kinesisClient.describeStream(any(DescribeStreamRequest.class))).thenReturn(expectedStreamRequest);
  this.connector.start(TestData.settings());

  List<Map<String, String>> taskConfigs = this.connector.taskConfigs(SHARD_COUNT);
  assertEquals(SHARD_COUNT, taskConfigs.size());
  verify(this.kinesisClient, atLeastOnce()).describeStream(expectedDescribeStreamRequest);
}

private String getShardItertor() {
    // either return a cached one or get a new one via a GetShardIterator request.
    if (currentShardIterator == null) {
        String shardId;

        //If ShardId supplied use it, else choose first one
        if (!getEndpoint().getShardId().isEmpty()) {
            shardId = getEndpoint().getShardId();
        } else {
            DescribeStreamRequest req1 = new DescribeStreamRequest()
                    .withStreamName(getEndpoint().getStreamName());
            DescribeStreamResult res1 = getClient().describeStream(req1);
            shardId = res1.getStreamDescription().getShards().get(0).getShardId();
        }
        LOG.debug("ShardId is: {}", shardId);

        GetShardIteratorRequest req = new GetShardIteratorRequest()
                .withStreamName(getEndpoint().getStreamName())
                .withShardId(shardId)
                .withShardIteratorType(getEndpoint().getIteratorType());

        if (hasSequenceNumber()) {
            req.withStartingSequenceNumber(getEndpoint().getSequenceNumber());
        }

        GetShardIteratorResult result = getClient().getShardIterator(req);
        currentShardIterator = result.getShardIterator();
    }
    LOG.debug("Shard Iterator is: {}", currentShardIterator);
    return currentShardIterator;
}

@Test
public void itObtainsAShardIteratorOnFirstPoll() throws Exception {
    undertest.poll();

    final ArgumentCaptor<DescribeStreamRequest> describeStreamReqCap = ArgumentCaptor.forClass(DescribeStreamRequest.class);
    final ArgumentCaptor<GetShardIteratorRequest> getShardIteratorReqCap = ArgumentCaptor.forClass(GetShardIteratorRequest.class);

    verify(kinesisClient).describeStream(describeStreamReqCap.capture());
    assertThat(describeStreamReqCap.getValue().getStreamName(), is("streamName"));

    verify(kinesisClient).getShardIterator(getShardIteratorReqCap.capture());
    assertThat(getShardIteratorReqCap.getValue().getStreamName(), is("streamName"));
    assertThat(getShardIteratorReqCap.getValue().getShardId(), is("shardId"));
    assertThat(getShardIteratorReqCap.getValue().getShardIteratorType(), is("LATEST"));
}

@Test
public void itDoesNotMakeADescribeStreamRequestIfShardIdIsSet() throws Exception {
    undertest.getEndpoint().setShardId("shardIdPassedAsUrlParam");

    undertest.poll();

    verify(kinesisClient, never()).describeStream(any(DescribeStreamRequest.class));

    final ArgumentCaptor<GetShardIteratorRequest> getShardIteratorReqCap = ArgumentCaptor.forClass(GetShardIteratorRequest.class);

    verify(kinesisClient).getShardIterator(getShardIteratorReqCap.capture());
    assertThat(getShardIteratorReqCap.getValue().getStreamName(), is("streamName"));
    assertThat(getShardIteratorReqCap.getValue().getShardId(), is("shardIdPassedAsUrlParam"));
    assertThat(getShardIteratorReqCap.getValue().getShardIteratorType(), is("LATEST"));
}

@Test
public void itUsesTheShardIteratorOnSubsiquentPolls() throws Exception {
    undertest.poll();
    undertest.poll();

    final ArgumentCaptor<GetRecordsRequest> getRecordsReqCap = ArgumentCaptor.forClass(GetRecordsRequest.class);

    verify(kinesisClient, times(1)).describeStream(any(DescribeStreamRequest.class));
    verify(kinesisClient, times(1)).getShardIterator(any(GetShardIteratorRequest.class));
    verify(kinesisClient, times(2)).getRecords(getRecordsReqCap.capture());
    assertThat(getRecordsReqCap.getAllValues().get(0).getShardIterator(), is("shardIterator"));
    assertThat(getRecordsReqCap.getAllValues().get(1).getShardIterator(), is("nextShardIterator"));
}

/**
 * Helper method to determine if an Amazon Kinesis stream exists.
 * 
 * @param kinesisClient
 *        The {@link AmazonKinesisClient} with Amazon Kinesis read privileges
 * @param streamName
 *        The Amazon Kinesis stream to check for
 * @return true if the Amazon Kinesis stream exists, otherwise return false
 */
private static boolean streamExists(AmazonKinesisClient kinesisClient, String streamName) {
    DescribeStreamRequest describeStreamRequest = new DescribeStreamRequest();
    describeStreamRequest.setStreamName(streamName);
    try {
        kinesisClient.describeStream(describeStreamRequest);
        return true;
    } catch (ResourceNotFoundException e) {
        return false;
    }
}

/**
 * Return the state of a Amazon Kinesis stream.
 * 
 * @param kinesisClient
 *        The {@link AmazonKinesisClient} with Amazon Kinesis read privileges
 * @param streamName
 *        The Amazon Kinesis stream to get the state of
 * @return String representation of the Stream state
 */
private static String streamState(AmazonKinesisClient kinesisClient, String streamName) {
    DescribeStreamRequest describeStreamRequest = new DescribeStreamRequest();
    describeStreamRequest.setStreamName(streamName);
    try {
        return kinesisClient.describeStream(describeStreamRequest).getStreamDescription().getStreamStatus();
    } catch (AmazonServiceException e) {
        return null;
    }
}

private static boolean streamActive(AmazonKinesis client, String streamName) {
  try {
    DescribeStreamRequest describeStreamRequest = new DescribeStreamRequest();
    describeStreamRequest.setStreamName(streamName);
    DescribeStreamResult describeStreamResult = client.describeStream(describeStreamRequest);
    String streamStatus = describeStreamResult.getStreamDescription().getStreamStatus();
    if ("ACTIVE".equals(streamStatus)) {
      return true;
    }
  } catch (Exception e) {
    return false;
  }
  return false;
}

/**
 * Internal method to retrieve the stream description and get the shards from AWS.
 *
 * Gets from the internal cache unless not yet created or too old.
 *
 * @param streamName
 * @return
 */
protected InternalStreamDescription getStreamDescription(String streamName)
{
    InternalStreamDescription desc = this.streamMap.get(streamName);
    if (desc == null || System.currentTimeMillis() - desc.getCreateTimeStamp() >= MAX_CACHE_AGE_MILLIS) {
        desc = new InternalStreamDescription(streamName);

        DescribeStreamRequest describeStreamRequest = clientManager.getDescribeStreamRequest();
        describeStreamRequest.setStreamName(streamName);

        // Collect shards from Kinesis
        String exclusiveStartShardId = null;
        List<Shard> shards = new ArrayList<>();
        do {
            describeStreamRequest.setExclusiveStartShardId(exclusiveStartShardId);
            DescribeStreamResult describeStreamResult = clientManager.getClient().describeStream(describeStreamRequest);

            String streamStatus = describeStreamResult.getStreamDescription().getStreamStatus();
            if (!streamStatus.equals("ACTIVE") && !streamStatus.equals("UPDATING")) {
                throw new ResourceNotFoundException("Stream not Active");
            }

            desc.addAllShards(describeStreamResult.getStreamDescription().getShards());

            if (describeStreamResult.getStreamDescription().getHasMoreShards() && (shards.size() > 0)) {
                exclusiveStartShardId = shards.get(shards.size() - 1).getShardId();
            }
            else {
                exclusiveStartShardId = null;
            }
        } while (exclusiveStartShardId != null);

        this.streamMap.put(streamName, desc);
    }

    return desc;
}

@Override
public DescribeStreamResult describeStream(DescribeStreamRequest describeStreamRequest) throws AmazonServiceException, AmazonClientException
{
    InternalStream theStream = this.getStream(describeStreamRequest.getStreamName());
    if (theStream != null) {
        StreamDescription desc = new StreamDescription();
        desc = desc.withStreamName(theStream.getStreamName()).withStreamStatus(theStream.getStreamStatus()).withStreamARN(theStream.getStreamARN());

        if (describeStreamRequest.getExclusiveStartShardId() == null || describeStreamRequest.getExclusiveStartShardId().isEmpty()) {
            desc.setShards(this.getShards(theStream));
            desc.setHasMoreShards(false);
        }
        else {
            // Filter from given shard Id, or may not have any more
            String startId = describeStreamRequest.getExclusiveStartShardId();
            desc.setShards(this.getShards(theStream, startId));
            desc.setHasMoreShards(false);
        }

        DescribeStreamResult result = new DescribeStreamResult();
        result = result.withStreamDescription(desc);
        return result;
    }
    else {
        throw new AmazonClientException("This stream does not exist!");
    }
}

private String checkStreamStatus(String streamName)
{
    DescribeStreamRequest describeStreamRequest = new DescribeStreamRequest();
    describeStreamRequest.setStreamName(streamName);

    StreamDescription streamDescription = amazonKinesisClient.describeStream(describeStreamRequest).getStreamDescription();
    return streamDescription.getStreamStatus();
}

/**
 * Helper method to determine if an Amazon Kinesis stream exists.
 * 
 * @param kinesisClient
 *        The {@link AmazonKinesisClient} with Amazon Kinesis read privileges
 * @param streamName
 *        The Amazon Kinesis stream to check for
 * @return true if the Amazon Kinesis stream exists, otherwise return false
 */
private static boolean streamExists(AmazonKinesisClient kinesisClient, String streamName) {
    DescribeStreamRequest describeStreamRequest = new DescribeStreamRequest();
    describeStreamRequest.setStreamName(streamName);
    try {
        kinesisClient.describeStream(describeStreamRequest);
        return true;
    } catch (ResourceNotFoundException e) {
        return false;
    }
}

/**
 * Return the state of a Amazon Kinesis stream.
 * 
 * @param kinesisClient
 *        The {@link AmazonKinesisClient} with Amazon Kinesis read privileges
 * @param streamName
 *        The Amazon Kinesis stream to get the state of
 * @return String representation of the Stream state
 */
private static String streamState(AmazonKinesisClient kinesisClient, String streamName) {
    DescribeStreamRequest describeStreamRequest = new DescribeStreamRequest();
    describeStreamRequest.setStreamName(streamName);
    try {
        return kinesisClient.describeStream(describeStreamRequest).getStreamDescription().getStreamStatus();
    } catch (AmazonServiceException e) {
        return null;
    }
}

/**
 * Wait up to the specified time for the stream to be created
 * @param topic
 * @param minutesToWait
 */
private void waitForStreamToBecomeAvailable(final String topic, final int minutesToWait) {

    /** Ask for no more than 10 shards at a time -- this is an optional parameter **/
    final int shardsToQuery =  10;

    LOGGER.info("Waiting for topic {} to become ACTIVE...", topic);

    final long startTime = System.currentTimeMillis();
    final long endTime = startTime + (minutesToWait * 60L * 1000L);
    final long sleepTime = (1000L * 10L);

    while (System.currentTimeMillis() < endTime) {
        try {
            Thread.sleep(sleepTime);
        } catch (InterruptedException e) {
            // Ignore interruption (doesn't impact stream creation)
        }
        try {

            final DescribeStreamRequest describeStreamRequest = new DescribeStreamRequest();
            describeStreamRequest.setStreamName(topic);
            describeStreamRequest.setLimit(shardsToQuery);
            /** stream response **/
            final DescribeStreamResult describeStreamResponse = this.client.describeStream(describeStreamRequest);
            final String streamStatus = describeStreamResponse.getStreamDescription().getStreamStatus();
            LOGGER.info("Topic: {} Current state: {}", topic, streamStatus);
            if (streamStatus.equals("ACTIVE")) {
                return;
            }
        } catch (AmazonServiceException ase) {
            if (ase.getErrorCode().equalsIgnoreCase("ResourceNotFoundException") == false) {
                throw ase;
            }
            throw new RuntimeException("Stream " + topic + " never became active");
        }
    }
 }

public static void createStream(AmazonKinesisClient client, String streamName) throws Exception {

        client.createStream(streamName, 1);

        Waiter<DescribeStreamRequest> waiter = client.waiters().streamExists();
        DescribeStreamRequest request = new DescribeStreamRequest().withStreamName(streamName);
        Assert.assertNotNull("Cannot obtain stream description", request);
        Future<Void> future = waiter.runAsync(new WaiterParameters<DescribeStreamRequest>(request), new NoOpWaiterHandler());
        future.get(1, TimeUnit.MINUTES);
    }

@Override
public DescribeStreamResult describeStream(DescribeStreamRequest describeStreamRequest) {
  throw new RuntimeException("Not implemented");
}

/**
 * Get metainfo for a Kinesis stream, which contains information about which shards this Kinesis stream possess.
 *
 * <p>This method is using a "full jitter" approach described in AWS's article,
 * <a href="https://www.awsarchitectureblog.com/2015/03/backoff.html">"Exponential Backoff and Jitter"</a>.
 * This is necessary because concurrent calls will be made by all parallel subtask's fetcher. This
 * jitter backoff approach will help distribute calls across the fetchers over time.
 *
 * @param streamName the stream to describe
 * @param startShardId which shard to start with for this describe operation (earlier shard's infos will not appear in result)
 * @return the result of the describe stream operation
 */
private DescribeStreamResult describeStream(String streamName, @Nullable String startShardId) throws InterruptedException {
    final DescribeStreamRequest describeStreamRequest = new DescribeStreamRequest();
    describeStreamRequest.setStreamName(streamName);
    describeStreamRequest.setExclusiveStartShardId(startShardId);

    DescribeStreamResult describeStreamResult = null;

    // Call DescribeStream, with full-jitter backoff (if we get LimitExceededException).
    int attemptCount = 0;
    while (describeStreamResult == null) { // retry until we get a result
        try {
            describeStreamResult = kinesisClient.describeStream(describeStreamRequest);
        } catch (LimitExceededException le) {
            long backoffMillis = fullJitterBackoff(
                describeStreamBaseBackoffMillis, describeStreamMaxBackoffMillis, describeStreamExpConstant, attemptCount++);
            LOG.warn("Got LimitExceededException when describing stream " + streamName + ". Backing off for "
                + backoffMillis + " millis.");
            Thread.sleep(backoffMillis);
        } catch (ResourceNotFoundException re) {
            throw new RuntimeException("Error while getting stream details", re);
        }
    }

    String streamStatus = describeStreamResult.getStreamDescription().getStreamStatus();
    if (!(streamStatus.equals(StreamStatus.ACTIVE.toString()) || streamStatus.equals(StreamStatus.UPDATING.toString()))) {
        if (LOG.isWarnEnabled()) {
            LOG.warn("The status of stream " + streamName + " is " + streamStatus + "; result of the current " +
                "describeStream operation will not contain any shard information.");
        }
    }

    // Kinesalite (mock implementation of Kinesis) does not correctly exclude shards before the exclusive
    // start shard id in the returned shards list; check if we need to remove these erroneously returned shards
    if (startShardId != null) {
        List<Shard> shards = describeStreamResult.getStreamDescription().getShards();
        Iterator<Shard> shardItr = shards.iterator();
        while (shardItr.hasNext()) {
            if (StreamShardHandle.compareShardIds(shardItr.next().getShardId(), startShardId) <= 0) {
                shardItr.remove();
            }
        }
    }

    return describeStreamResult;
}

/**
 * Get metainfo for a Kinesis stream, which contains information about which shards this Kinesis stream possess.
 *
 * This method is using a "full jitter" approach described in AWS's article,
 * <a href="https://www.awsarchitectureblog.com/2015/03/backoff.html">"Exponential Backoff and Jitter"</a>.
 * This is necessary because concurrent calls will be made by all parallel subtask's fetcher. This
 * jitter backoff approach will help distribute calls across the fetchers over time.
 *
 * @param streamName the stream to describe
 * @param startShardId which shard to start with for this describe operation (earlier shard's infos will not appear in result)
 * @return the result of the describe stream operation
 */
private DescribeStreamResult describeStream(String streamName, @Nullable String startShardId) throws InterruptedException {
    final DescribeStreamRequest describeStreamRequest = new DescribeStreamRequest();
    describeStreamRequest.setStreamName(streamName);
    describeStreamRequest.setExclusiveStartShardId(startShardId);

    DescribeStreamResult describeStreamResult = null;

    // Call DescribeStream, with full-jitter backoff (if we get LimitExceededException).
    int attemptCount = 0;
    while (describeStreamResult == null) { // retry until we get a result
        try {
            describeStreamResult = kinesisClient.describeStream(describeStreamRequest);
        } catch (LimitExceededException le) {
            long backoffMillis = fullJitterBackoff(
                describeStreamBaseBackoffMillis, describeStreamMaxBackoffMillis, describeStreamExpConstant, attemptCount++);
            LOG.warn("Got LimitExceededException when describing stream " + streamName + ". Backing off for "
                + backoffMillis + " millis.");
            Thread.sleep(backoffMillis);
        } catch (ResourceNotFoundException re) {
            throw new RuntimeException("Error while getting stream details", re);
        }
    }

    String streamStatus = describeStreamResult.getStreamDescription().getStreamStatus();
    if (!(streamStatus.equals(StreamStatus.ACTIVE.toString()) || streamStatus.equals(StreamStatus.UPDATING.toString()))) {
        if (LOG.isWarnEnabled()) {
            LOG.warn("The status of stream " + streamName + " is " + streamStatus + "; result of the current " +
                "describeStream operation will not contain any shard information.");
        }
    }

    // Kinesalite (mock implementation of Kinesis) does not correctly exclude shards before the exclusive
    // start shard id in the returned shards list; check if we need to remove these erroneously returned shards
    if (startShardId != null) {
        List<Shard> shards = describeStreamResult.getStreamDescription().getShards();
        Iterator<Shard> shardItr = shards.iterator();
        while (shardItr.hasNext()) {
            if (KinesisStreamShard.compareShardIds(shardItr.next().getShardId(), startShardId) <= 0) {
                shardItr.remove();
            }
        }
    }

    return describeStreamResult;
}

@Override
public DescribeStreamRequest getDescribeStreamRequest()
{
    return new DescribeStreamRequest();
}

@Override
public DescribeStreamRequest getDescribeStreamRequest()
{
    return new DescribeStreamRequest();
}

public static void main(String[] args) {
    AmazonKinesisClient kinesisClient = Helper.setupKinesisClient();

    // Retrieve the Shards from a Stream
    DescribeStreamRequest describeStreamRequest = new DescribeStreamRequest();
    describeStreamRequest.setStreamName(Helper.properties().getProperty("kinesisStreamName"));
    DescribeStreamResult describeStreamResult;
    List<Shard> shards = new ArrayList<>();
    String lastShardId = null;

    do {
        describeStreamRequest.setExclusiveStartShardId(lastShardId);
        describeStreamResult = kinesisClient.describeStream(describeStreamRequest);
        shards.addAll(describeStreamResult.getStreamDescription().getShards());
        if (shards.size() > 0) {
            lastShardId = shards.get(shards.size() - 1).getShardId();
        }
    } while (describeStreamResult.getStreamDescription().getHasMoreShards());

    // Get Data from the Shards in a Stream
    // Hard-coded to use only 1 shard
    String shardIterator;
    GetShardIteratorRequest getShardIteratorRequest = new GetShardIteratorRequest();
    getShardIteratorRequest.setStreamName(Helper.properties().getProperty("kinesisStreamName"));
    getShardIteratorRequest.setShardId(shards.get(0).getShardId());
    getShardIteratorRequest.setShardIteratorType("TRIM_HORIZON");

    GetShardIteratorResult getShardIteratorResult = kinesisClient.getShardIterator(getShardIteratorRequest);
    shardIterator = getShardIteratorResult.getShardIterator();

    // Continuously read data records from shard.
    List<Record> records;
    while (true) {
        // Create new GetRecordsRequest with existing shardIterator.
        // Set maximum records to return to 1000.
        GetRecordsRequest getRecordsRequest = new GetRecordsRequest();
        getRecordsRequest.setShardIterator(shardIterator);
        getRecordsRequest.setLimit(1000);

        GetRecordsResult result = kinesisClient.getRecords(getRecordsRequest);

        // Put result into record list. Result may be empty.
        records = result.getRecords();

        // Print records
        for (Record record : records) {
            ByteBuffer byteBuffer = record.getData();
            System.out.println(String.format("Seq No: %s - %s", record.getSequenceNumber(),
                    new String(byteBuffer.array())));
        }

        try {
            Thread.sleep(1000);
        } catch (InterruptedException exception) {
            throw new RuntimeException(exception);
        }

        shardIterator = result.getNextShardIterator();
    }
}

DescribeStreamRequest getDescribeStreamRequest();