kafka.javaapi.message.ByteBufferMessageSet Java Examples

private boolean verifyMessage(String key, String message) {
    long lastMessageOffset = KafkaUtils.getOffset(simpleConsumer, kafkaConfig.topic, 0, OffsetRequest.LatestTime()) - 1;
    ByteBufferMessageSet messageAndOffsets = KafkaUtils.fetchMessages(kafkaConfig, simpleConsumer,
            new Partition(Broker.fromString(broker.getBrokerConnectionString()), 0), lastMessageOffset);
    MessageAndOffset messageAndOffset = messageAndOffsets.iterator().next();
    Message kafkaMessage = messageAndOffset.message();
    ByteBuffer messageKeyBuffer = kafkaMessage.key();
    String keyString = null;
    String messageString = new String(Utils.toByteArray(kafkaMessage.payload()));
    if (messageKeyBuffer != null) {
        keyString = new String(Utils.toByteArray(messageKeyBuffer));
    }
    assertEquals(key, keyString);
    assertEquals(message, messageString);
    return true;
}
 

/**
 * re-emit the batch described by the meta data provided
 *
 * @param attempt
 * @param collector
 * @param partition
 * @param meta
 */
private void reEmitPartitionBatch(TransactionAttempt attempt, TridentCollector collector, Partition partition, Map meta) {
    LOG.info("re-emitting batch, attempt " + attempt);
    String instanceId = (String) meta.get("instanceId");
    if (!_config.forceFromStart || instanceId.equals(_topologyInstanceId)) {
        SimpleConsumer consumer = _connections.register(partition);
        long offset = (Long) meta.get("offset");
        long nextOffset = (Long) meta.get("nextOffset");
        ByteBufferMessageSet msgs = fetchMessages(consumer, partition, offset);
        for (MessageAndOffset msg : msgs) {
            if (offset == nextOffset) {
                break;
            }
            if (offset > nextOffset) {
                throw new RuntimeException("Error when re-emitting batch. overshot the end offset");
            }
            emit(collector, msg.message());
            offset = msg.nextOffset();
        }
    }
}
 

/**
 * Creates an Iterator of FetchedMessage based on the given message set. The iterator would also updates
 * the offset while iterating.
 */
private Iterator<FetchedMessage> createFetchedMessages(ByteBufferMessageSet messageSet, final AtomicLong offset) {
  final Iterator<MessageAndOffset> messages = messageSet.iterator();
  return new AbstractIterator<FetchedMessage>() {
    @Override
    protected FetchedMessage computeNext() {
      while (messages.hasNext()) {
        MessageAndOffset message = messages.next();
        long msgOffset = message.offset();
        if (msgOffset < offset.get()) {
          LOG.trace("Received old offset {}, expecting {} on {}. Message Ignored.",
                    msgOffset, offset.get(), topicPart);
          continue;
        }

        fetchedMessage.setPayload(message.message().payload());
        fetchedMessage.setOffset(message.offset());
        fetchedMessage.setNextOffset(message.nextOffset());

        return fetchedMessage;
      }
      return endOfData();
    }
  };
}
 

public static void main(String[] args) throws Exception {
	final String topic = "topic1";
	String clientID = "DemoLowLevelConsumer1";
	SimpleConsumer simpleConsumer = new SimpleConsumer("kafka0", 9092, 100000, 64 * 1000000, clientID);
	FetchRequest req = new FetchRequestBuilder().clientId(clientID)
			.addFetch(topic, 0, 0L, 50).addFetch(topic, 1, 0L, 5000).addFetch(topic, 2, 0L, 1000000).build();
	FetchResponse fetchResponse = simpleConsumer.fetch(req);
	ByteBufferMessageSet messageSet = (ByteBufferMessageSet) fetchResponse.messageSet(topic, 0);
	for (MessageAndOffset messageAndOffset : messageSet) {
		ByteBuffer payload = messageAndOffset.message().payload();
		long offset = messageAndOffset.offset();
		byte[] bytes = new byte[payload.limit()];
		payload.get(bytes);
		System.out.println("Offset:" + offset + ", Payload:" + new String(bytes, "UTF-8"));
	}
}
 

@Override
  public void run()
  {
    long offset = 0;
    while (isAlive) {
      // create a fetch request for topic “topic1”, partition 0, current offset, and fetch size of 1MB
      FetchRequest fetchRequest = new FetchRequestBuilder().clientId("default_client").addFetch("topic1", 1, offset, 1000000).build();

//      FetchRequest fetchRequest = new FetchRequest("topic1", 0, offset, 1000000);

      // get the message set from the consumer and print them out
      ByteBufferMessageSet messages = consumer.fetch(fetchRequest).messageSet("topic1", 1);
      Iterator<MessageAndOffset> itr = messages.iterator();

      while (itr.hasNext() && isAlive) {
        MessageAndOffset msg = itr.next();
        // advance the offset after consuming each message
        offset = msg.offset();
        logger.debug("consumed: {} offset: {}", byteBufferToString(msg.message().payload()).toString(), offset);
        receiveCount++;
      }
    }
  }
 

private void fill() {
    long start = System.nanoTime();
    ByteBufferMessageSet msgs = KafkaUtils.fetchMessages(_spoutConfig, _consumer, _partition, _emittedToOffset);
    long end = System.nanoTime();
    long millis = (end - start) / 1000000;
    _fetchAPILatencyMax.update(millis);
    _fetchAPILatencyMean.update(millis);
    _fetchAPICallCount.incr();
    int numMessages = countMessages(msgs);
    _fetchAPIMessageCount.incrBy(numMessages);

    if (numMessages > 0) {
        LOG.info("Fetched " + numMessages + " messages from: " + _partition);
    }
    for (MessageAndOffset msg : msgs) {
        _pending.add(_emittedToOffset);
        _waitingToEmit.add(new MessageAndRealOffset(msg.message(), _emittedToOffset));
        _emittedToOffset = msg.nextOffset();
    }
    if (numMessages > 0) {
        LOG.info("Added " + numMessages + " messages from: " + _partition + " to internal buffers");
    }
}
 

private Iterator<KafkaConsumerRecord> getIteratorFromFetchResponse(FetchResponse fetchResponse, KafkaPartition partition) {
  try {
    ByteBufferMessageSet messageBuffer = fetchResponse.messageSet(partition.getTopicName(), partition.getId());
    return Iterators.transform(messageBuffer.iterator(),
        new Function<kafka.message.MessageAndOffset, KafkaConsumerRecord>() {
          @Override
          public KafkaConsumerRecord apply(kafka.message.MessageAndOffset input) {
            return new Kafka08ConsumerRecord(input, partition.getTopicName(), partition.getId());
          }
        });
  } catch (Exception e) {
    log.warn(String.format("Failed to retrieve next message buffer for partition %s: %s."
        + "The remainder of this partition will be skipped.", partition, e));
    return null;
  }
}
 

private Iterable<MessageAndOffset> buildOffsetFilteringIterable(final ByteBufferMessageSet messageAndOffsets,
    final long startOffset, final long endOffset) {
  return Iterables.filter(messageAndOffsets, input -> {
    // Filter messages that are either null or have an offset ∉ [startOffset; endOffset[
    if (input == null || input.offset() < startOffset || (endOffset <= input.offset() && endOffset != -1)) {
      return false;
    }

    // Check the message's checksum
    // TODO We might want to have better handling of this situation, maybe try to fetch the message again?
    if (!input.message().isValid()) {
      LOGGER.warn("Discarded message with invalid checksum in partition {} of topic {}", _partition, _topic);
      return false;
    }

    return true;
  });
}
 

private void fillMessages() {

        ByteBufferMessageSet msgs;
        try {
            long start = System.currentTimeMillis();
            msgs = consumer.fetchMessages(partition, emittingOffset + 1);
            
            if (msgs == null) {
                LOG.error("fetch null message from offset {}", emittingOffset);
                return;
            }
            
            int count = 0;
            for (MessageAndOffset msg : msgs) {
                count += 1;
                emittingMessages.add(msg);
                emittingOffset = msg.offset();
                pendingOffsets.add(emittingOffset);
                LOG.debug("fillmessage fetched a message:{}, offset:{}", msg.message().toString(), msg.offset());
            }
            long end = System.currentTimeMillis();
            LOG.info("fetch message from partition:"+partition+", offset:" + emittingOffset+", size:"+msgs.sizeInBytes()+", count:"+count +", time:"+(end-start));
        } catch (Exception e) {
            e.printStackTrace();
            LOG.error(e.getMessage(),e);
        }
    }
 

public void testFetch()
{
	expect(mockConsumer.fetch(anyObject(FetchRequest.class))).andReturn(new ByteBufferMessageSet(Collections.EMPTY_LIST));	
	replay(mockConsumer, mockCurator);		
	client.fetch("my_topic", 0, 1717, 1024);
	verify(mockConsumer, mockCurator);
}
 

private Map doEmitNewPartitionBatch(SimpleConsumer consumer, Partition partition, TridentCollector collector, Map lastMeta) {
    long offset;
    if (lastMeta != null) {
        String lastInstanceId = null;
        Map lastTopoMeta = (Map) lastMeta.get("topology");
        if (lastTopoMeta != null) {
            lastInstanceId = (String) lastTopoMeta.get("id");
        }
        if (_config.forceFromStart && !_topologyInstanceId.equals(lastInstanceId)) {
            offset = KafkaUtils.getOffset(consumer, _config.topic, partition.partition, _config.startOffsetTime);
        } else {
            offset = (Long) lastMeta.get("nextOffset");
        }
    } else {
        offset = KafkaUtils.getOffset(consumer, _config.topic, partition.partition, _config);
    }
    ByteBufferMessageSet msgs = fetchMessages(consumer, partition, offset);
    long endoffset = offset;
    for (MessageAndOffset msg : msgs) {
        emit(collector, msg.message());
        endoffset = msg.nextOffset();
    }
    Map newMeta = new HashMap();
    newMeta.put("offset", offset);
    newMeta.put("nextOffset", endoffset);
    newMeta.put("instanceId", _topologyInstanceId);
    newMeta.put("partition", partition.partition);
    newMeta.put("broker", ImmutableMap.of("host", partition.host.host, "port", partition.host.port));
    newMeta.put("topic", _config.topic);
    newMeta.put("topology", ImmutableMap.of("name", _topologyName, "id", _topologyInstanceId));
    return newMeta;
}
 

private ByteBufferMessageSet fetchMessages(SimpleConsumer consumer, Partition partition, long offset) {
    long start = System.nanoTime();
    ByteBufferMessageSet msgs = KafkaUtils.fetchMessages(_config, consumer, partition, offset);
    long end = System.nanoTime();
    long millis = (end - start) / 1000000;
    _kafkaMeanFetchLatencyMetric.update(millis);
    _kafkaMaxFetchLatencyMetric.update(millis);
    return msgs;
}
 

private int countMessages(ByteBufferMessageSet messageSet) {
    int counter = 0;
    for (MessageAndOffset messageAndOffset : messageSet) {
        counter = counter + 1;
    }
    return counter;
}
 

public static ByteBufferMessageSet fetchMessages(KafkaConfig config, SimpleConsumer consumer, Partition partition, long offset) {
    ByteBufferMessageSet msgs = null;
    String topic = config.topic;
    int partitionId = partition.partition;
    for (int errors = 0; errors < 2 && msgs == null; errors++) {
        FetchRequestBuilder builder = new FetchRequestBuilder();
        FetchRequest fetchRequest = builder.addFetch(topic, partitionId, offset, config.fetchSizeBytes).
                clientId(config.clientId).build();
        FetchResponse fetchResponse;
        try {
            fetchResponse = consumer.fetch(fetchRequest);
        } catch (Exception e) {
            if (e instanceof ConnectException) {
                throw new FailedFetchException(e);
            } else {
                throw new RuntimeException(e);
            }
        }
        if (fetchResponse.hasError()) {
            KafkaError error = KafkaError.getError(fetchResponse.errorCode(topic, partitionId));
            if (error.equals(KafkaError.OFFSET_OUT_OF_RANGE) && config.useStartOffsetTimeIfOffsetOutOfRange && errors == 0) {
                long startOffset = getOffset(consumer, topic, partitionId, config.startOffsetTime);
                LOG.warn("Got fetch request with offset out of range: [" + offset + "]; " +
                        "retrying with default start offset time from configuration. " +
                        "configured start offset time: [" + config.startOffsetTime + "] offset: [" + startOffset + "]");
                offset = startOffset;
            } else {
                String message = "Error fetching data from [" + partition + "] for topic [" + topic + "]: [" + error + "]";
                LOG.error(message);
                throw new FailedFetchException(message);
            }
        } else {
            msgs = fetchResponse.messageSet(topic, partitionId);
        }
    }
    return msgs;
}
 

@Test
public void fetchMessage() throws Exception {
    String value = "test";
    createTopicAndSendMessage(value);
    long offset = KafkaUtils.getOffset(simpleConsumer, config.topic, 0, OffsetRequest.LatestTime()) - 1;
    ByteBufferMessageSet messageAndOffsets = KafkaUtils.fetchMessages(config, simpleConsumer,
            new Partition(Broker.fromString(broker.getBrokerConnectionString()), 0), offset);
    String message = new String(Utils.toByteArray(messageAndOffsets.iterator().next().message().payload()));
    assertThat(message, is(equalTo(value)));
}
 

@Test
public void fetchMessagesWithInvalidOffsetAndDefaultHandlingEnabled() throws Exception {
    config = new KafkaConfig(brokerHosts, "newTopic");
    String value = "test";
    createTopicAndSendMessage(value);
    ByteBufferMessageSet messageAndOffsets = KafkaUtils.fetchMessages(config, simpleConsumer,
            new Partition(Broker.fromString(broker.getBrokerConnectionString()), 0), -99);
    String message = new String(Utils.toByteArray(messageAndOffsets.iterator().next().message().payload()));
    assertThat(message, is(equalTo(value)));
}
 

@Test
public void generateTuplesWithKeyAndKeyValueScheme() {
    config.scheme = new KeyValueSchemeAsMultiScheme(new StringKeyValueScheme());
    String value = "value";
    String key = "key";
    createTopicAndSendMessage(key, value);
    ByteBufferMessageSet messageAndOffsets = getLastMessage();
    for (MessageAndOffset msg : messageAndOffsets) {
        Iterable<List<Object>> lists = KafkaUtils.generateTuples(config, msg.message());
        assertEquals(ImmutableMap.of(key, value), lists.iterator().next().get(0));
    }
}
 

@Test
public void generateTuplesWithValueSchemeAndKeyValueMessage() {
    config.scheme = new SchemeAsMultiScheme(new StringScheme());
    String value = "value";
    String key = "key";
    createTopicAndSendMessage(key, value);
    ByteBufferMessageSet messageAndOffsets = getLastMessage();
    for (MessageAndOffset msg : messageAndOffsets) {
        Iterable<List<Object>> lists = KafkaUtils.generateTuples(config, msg.message());
        assertEquals(value, lists.iterator().next().get(0));
    }
}
 

private void runGetValueOnlyTuplesTest() {
    String value = "value";
    createTopicAndSendMessage(null, value);
    ByteBufferMessageSet messageAndOffsets = getLastMessage();
    for (MessageAndOffset msg : messageAndOffsets) {
        Iterable<List<Object>> lists = KafkaUtils.generateTuples(config, msg.message());
        assertEquals(value, lists.iterator().next().get(0));
    }
}
 

public List<byte[]> execute() throws Exception {
  FetchRequest req = 
      new FetchRequestBuilder().
      clientId(name).
      addFetch(topic, partitionMetadata.partitionId(), currentOffset, fetchSize).
      minBytes(1).
      maxWait(maxWait).
      build();
  
  FetchResponse fetchResponse = consumer.fetch(req);
  if(fetchResponse.hasError()) {
    short errorCode = fetchResponse.errorCode(topic, partitionMetadata.partitionId());
    String msg = "Kafka error code = " + errorCode + ", Partition  " + partitionMetadata.partitionId() ;
    throw new Exception(msg);
  }
  List<byte[]> holder = new ArrayList<byte[]>();
  ByteBufferMessageSet messageSet = fetchResponse.messageSet(topic, partitionMetadata.partitionId());
  int count = 0;
  for(MessageAndOffset messageAndOffset : messageSet) {
    if (messageAndOffset.offset() < currentOffset) continue; //old offset, ignore
    ByteBuffer payload = messageAndOffset.message().payload();
    byte[] bytes = new byte[payload.limit()];
    payload.get(bytes);
    holder.add(bytes);
    currentOffset = messageAndOffset.nextOffset();
    count++;
    if(count == maxRead) break;
  }
  return holder ;
}
 

private int dispatch(FetchResponse response) {
   int numDispatched = 0;
   for(TopicAndPartition tap: new ArrayList<>(offsets.keySet())) {
      short errorCode = response.errorCode(tap.topic(), tap.partition());
      if(errorCode != 0) {
         logger.warn("Error reading from topic: [{}] partition: [{}]", tap.topic(), tap.partition(), ErrorMapping.exceptionFor(errorCode));
         continue;
      }

      ByteBufferMessageSet message = response.messageSet(tap.topic(), tap.partition());
      for(MessageAndOffset mao: message) {
         Long offset = offsets.get(tap);
         if(offset != null && offset > mao.offset()) {
            // skip older offsets
            continue;
         }
         KafkaConsumer handler = handlers.computeIfAbsent(tap, handlerFactory);
         if(handler == null) {
            logger.debug("No handler for topic: [{}] partition: [{}], this partition won't be processed", tap.topic(), tap.partition());
            offsets.remove(tap);
            handlers.remove(tap);
            break;
         }
         if(handler.apply(tap, mao.message())) {
            numDispatched++;
            offsets.put(tap, mao.nextOffset());
         }
         else {
            logger.debug("Done processing topic: [{}] partition: [{}]", tap.topic(), tap.partition());
            offsets.remove(tap);
            handlers.remove(tap);
            break;
         }
      }
   }

   return numDispatched;
}
 

void processNonEmptyMessageSet(ByteBufferMessageSet msgs)
{
	logger.debug("Processing {} bytes of messages ...", msgs.validBytes());
	BulkRequestBuilder bulkRequestBuilder = client.prepareBulk();
	handleMessages(bulkRequestBuilder, msgs);
	executeBuilder(bulkRequestBuilder);
	offset += msgs.validBytes();
	kafka.saveOffset(riverConfig.topic, riverConfig.partition, offset);
}
 

void handleMessages(BulkRequestBuilder bulkRequestBuilder, ByteBufferMessageSet msgs)
{
	long numMsg = 0;
	for(MessageAndOffset mo : msgs)
	{
		++numMsg;
		++stats.numMessages;
		try {
			msgHandler.handle(bulkRequestBuilder, mo.message());
		} catch (Exception e) {
			logger.warn("Failed handling message", e);
		}
	}
	logger.debug("handleMessages processed {} messages", numMsg);
}
 

@Override
public ByteBufferMessageSet messageSet(String topic, int partition) {
  if (errorMap.containsKey(new TopicAndPartition(topic, partition))) {
    throw new IllegalArgumentException();
  } else {
    // TODO Maybe generate dummy messages here?
    return new ByteBufferMessageSet(Collections.<Message>emptyList());
  }
}
 

private Iterator<MessageAndOffset> getIteratorFromFetchResponse(FetchResponse fetchResponse,
    KafkaPartition partition) {
  try {
    ByteBufferMessageSet messageBuffer = fetchResponse.messageSet(partition.getTopicName(), partition.getId());
    return messageBuffer.iterator();
  } catch (Exception e) {
    LOG.warn(String.format("Failed to retrieve next message buffer for partition %s: %s."
        + "The remainder of this partition will be skipped.", partition, e));
    return null;
  }
}
 

/**
 * Calls the message callback with the given message set.
 */
private void invokeCallback(ByteBufferMessageSet messages, AtomicLong offset) {
  long savedOffset = offset.get();
  try {
    offset.set(callback.onReceived(createFetchedMessages(messages, offset)));
  } catch (Throwable t) {
    LOG.error("Callback throws exception. Retry from offset {} for {}", startOffset, topicPart, t);
    offset.set(savedOffset);
  }
}
 

/**
 * Sleeps if the message set is empty.
 * @return {@code true} if it is empty, {@code false} otherwise.
 */
private boolean sleepIfEmpty(ByteBufferMessageSet messages) {
  if (Iterables.isEmpty(messages)) {
    LOG.trace("No message fetched. Sleep for {} ms before next fetch.", EMPTY_FETCH_WAIT);
    try {
      TimeUnit.MILLISECONDS.sleep(EMPTY_FETCH_WAIT);
    } catch (InterruptedException e) {
      // It's interrupted from stop, ok to ignore.
    }
    return true;
  }
  return false;
}
 

private static void printMessages(ByteBufferMessageSet messageSet) throws UnsupportedEncodingException {
    for (MessageAndOffset messageAndOffset : messageSet) {
        ByteBuffer payload = messageAndOffset.message().payload();
        byte[] bytes = new byte[payload.limit()];
        payload.get(bytes);
        System.out.println(new String(bytes, "UTF-8"));
    }
}
 

public void update(ByteBufferMessageSet bbms) {
   boolean anyMatches = false;
   V value = null;
   for(MessageAndOffset mao: bbms) {
      anyMatches = true;

      value = factory.apply(mao.message());
      logger.trace("Scanning for [{}] in [{}] at [{}]@[{},{},{}]: ", target, tap.partition(), value, startOffset, mao.offset(), endOffset);
      int delta = target.compareTo(value);
      if(delta == 0) {
         logger.debug("Found exact offset for partition: [{}] value: [{}]", tap.partition(), value);
         this.offset = mao.offset();
         return;
      }
      else if(delta > 0) { // not far enough
         this.startOffset = mao.offset();
      }
      else if(delta < 0) { // too far
         this.endOffset = mao.offset();
         break; // don't process the next message or we'll think we're past the end
      }
   }

   if((endOffset - startOffset) < 2) {
      logger.debug("Found offset for partition: [{}] value: [{}]", tap.partition(), value);
      this.offset = this.endOffset; // start with the next message after value
   }
   else if(!anyMatches) {
      logger.debug("Reached the end of partition [{}] using offset [{}]", tap.partition(), endOffset);
      this.offset = this.endOffset;
   }
}
 

public ByteBufferMessageSet fetchMessages(int partition, long offset) throws IOException {

        String topic = config.topic;
        FetchRequest req = new FetchRequestBuilder().clientId(config.clientId).addFetch(topic, partition, offset, config.fetchMaxBytes)
                .maxWait(config.fetchWaitMaxMs).build();
        FetchResponse fetchResponse = null;
        SimpleConsumer simpleConsumer = null;
        try {
            simpleConsumer = findLeaderConsumer(partition);
            if (simpleConsumer == null) {
                // LOG.error(message);
                return null;
            }
            fetchResponse = simpleConsumer.fetch(req);
        } catch (Exception e) {
            if (e instanceof ConnectException || e instanceof SocketTimeoutException || e instanceof IOException
                    || e instanceof UnresolvedAddressException) {
                LOG.warn("Network error when fetching messages:", e);
                if (simpleConsumer != null) {
                    String host = simpleConsumer.host();
                    int port = simpleConsumer.port();
                    simpleConsumer = null;
                    throw new KafkaException("Network error when fetching messages: " + host + ":" + port + " , " + e.getMessage(), e);
                }

            } else {
                throw new RuntimeException(e);
            }
        }
        if (fetchResponse.hasError()) {
            short code = fetchResponse.errorCode(topic, partition);
            if (code == ErrorMapping.OffsetOutOfRangeCode() && config.resetOffsetIfOutOfRange) {
                long startOffset = getOffset(topic, partition, config.startOffsetTime);
                offset = startOffset;
            }
            if(leaderBroker != null) {
                LOG.error("fetch data from kafka topic[" + config.topic + "] host[" + leaderBroker.host() + ":" + leaderBroker.port() + "] partition["
                    + partition + "] error:" + code);
            }else {
                
            }
            return null;
        } else {
            ByteBufferMessageSet msgs = fetchResponse.messageSet(topic, partition);
            return msgs;
        }
    }