io.vertx.kafka.client.consumer

Interface KafkaConsumer<K,V>

All Superinterfaces:

ReadStream<KafkaConsumerRecord<K,V>>, StreamBase

public interface KafkaConsumer<K,V>
extends ReadStream<KafkaConsumerRecord<K,V>>

Vert.x Kafka consumer.

You receive Kafka records by providing a handler(Handler). As messages arrive the handler will be called with the records.

The pause() and resume() provides global control over reading the records from the consumer.

The pause(Set) and resume(Set) provides finer grained control over reading records for specific Topic/Partition, these are Kafka's specific operations.

Method Summary

Modifier and Type	Method and Description
KafkaConsumer<K,V>	assign(Set<TopicPartition> topicPartitions) Manually assign a list of partition to this consumer.
KafkaConsumer<K,V>	assign(Set<TopicPartition> topicPartitions, Handler<AsyncResult<Void>> completionHandler) Manually assign a list of partition to this consumer.
KafkaConsumer<K,V>	assign(TopicPartition topicPartition) Manually assign a partition to this consumer.
KafkaConsumer<K,V>	assign(TopicPartition topicPartition, Handler<AsyncResult<Void>> completionHandler) Manually assign a partition to this consumer.
KafkaConsumer<K,V>	assignment(Handler<AsyncResult<Set<TopicPartition>>> handler) Get the set of partitions currently assigned to this consumer.
KafkaReadStream<K,V>	asStream()
KafkaConsumer<K,V>	batchHandler(Handler<KafkaConsumerRecords<K,V>> handler) Set the handler to be used when batches of messages are fetched from the Kafka server.
void	beginningOffsets(Set<TopicPartition> topicPartitions, Handler<AsyncResult<Map<TopicPartition,Long>>> handler) Get the first offset for the given partitions.
void	beginningOffsets(TopicPartition topicPartition, Handler<AsyncResult<Long>> handler) Get the first offset for the given partitions.
default void	close() Close the consumer
void	close(Handler<AsyncResult<Void>> completionHandler) Close the consumer
void	commit() Commit current offsets for all the subscribed list of topics and partition.
void	commit(Handler<AsyncResult<Void>> completionHandler) Commit current offsets for all the subscribed list of topics and partition.
void	commit(Map<TopicPartition,OffsetAndMetadata> offsets) Commit the specified offsets for the specified list of topics and partitions to Kafka.
void	commit(Map<TopicPartition,OffsetAndMetadata> offsets, Handler<AsyncResult<Map<TopicPartition,OffsetAndMetadata>>> completionHandler) Commit the specified offsets for the specified list of topics and partitions to Kafka.
void	committed(TopicPartition topicPartition, Handler<AsyncResult<OffsetAndMetadata>> handler) Get the last committed offset for the given partition (whether the commit happened by this process or another).
static <K,V> KafkaConsumer<K,V>	create(Vertx vertx, org.apache.kafka.clients.consumer.Consumer<K,V> consumer) Create a new KafkaConsumer instance from a native Consumer.
static <K,V> KafkaConsumer<K,V>	create(Vertx vertx, Map<String,String> config) Create a new KafkaConsumer instance
static <K,V> KafkaConsumer<K,V>	create(Vertx vertx, Map<String,String> config, Class<K> keyType, Class<V> valueType) Create a new KafkaConsumer instance
static <K,V> KafkaConsumer<K,V>	create(Vertx vertx, Map<String,String> config, org.apache.kafka.common.serialization.Deserializer<K> keyDeserializer, org.apache.kafka.common.serialization.Deserializer<V> valueDeserializer) Create a new KafkaConsumer instance
static <K,V> KafkaConsumer<K,V>	create(Vertx vertx, Properties config) Create a new KafkaConsumer instance
static <K,V> KafkaConsumer<K,V>	create(Vertx vertx, Properties config, Class<K> keyType, Class<V> valueType) Create a new KafkaConsumer instance
static <K,V> KafkaConsumer<K,V>	create(Vertx vertx, Properties config, org.apache.kafka.common.serialization.Deserializer<K> keyDeserializer, org.apache.kafka.common.serialization.Deserializer<V> valueDeserializer) Create a new KafkaConsumer instance
long	demand() Returns the current demand.
KafkaConsumer<K,V>	endHandler(Handler<Void> endHandler) Set an end handler.
void	endOffsets(Set<TopicPartition> topicPartitions, Handler<AsyncResult<Map<TopicPartition,Long>>> handler) Get the last offset for the given partitions.
void	endOffsets(TopicPartition topicPartition, Handler<AsyncResult<Long>> handler) Get the last offset for the given partition.
KafkaConsumer<K,V>	exceptionHandler(Handler<Throwable> handler) Set an exception handler on the read stream.
KafkaConsumer<K,V>	fetch(long amount) Fetch the specified amount of elements.
KafkaConsumer<K,V>	handler(Handler<KafkaConsumerRecord<K,V>> handler) Set a data handler.
KafkaConsumer<K,V>	listTopics(Handler<AsyncResult<Map<String,List<PartitionInfo>>>> handler) Get metadata about partitions for all topics that the user is authorized to view.
void	offsetsForTimes(Map<TopicPartition,Long> topicPartitionTimestamps, Handler<AsyncResult<Map<TopicPartition,OffsetAndTimestamp>>> handler) Look up the offsets for the given partitions by timestamp.
void	offsetsForTimes(TopicPartition topicPartition, Long timestamp, Handler<AsyncResult<OffsetAndTimestamp>> handler) Look up the offset for the given partition by timestamp.
KafkaConsumer<K,V>	partitionsAssignedHandler(Handler<Set<TopicPartition>> handler) Set the handler called when topic partitions are assigned to the consumer
KafkaConsumer<K,V>	partitionsFor(String topic, Handler<AsyncResult<List<PartitionInfo>>> handler) Get metadata about the partitions for a given topic.
KafkaConsumer<K,V>	partitionsRevokedHandler(Handler<Set<TopicPartition>> handler) Set the handler called when topic partitions are revoked to the consumer
KafkaConsumer<K,V>	pause() Pause the ReadStream, it sets the buffer in fetch mode and clears the actual demand.
KafkaConsumer<K,V>	pause(Set<TopicPartition> topicPartitions) Suspend fetching from the requested partitions.
KafkaConsumer<K,V>	pause(Set<TopicPartition> topicPartitions, Handler<AsyncResult<Void>> completionHandler) Suspend fetching from the requested partitions.
KafkaConsumer<K,V>	pause(TopicPartition topicPartition) Suspend fetching from the requested partition.
KafkaConsumer<K,V>	pause(TopicPartition topicPartition, Handler<AsyncResult<Void>> completionHandler) Suspend fetching from the requested partition.
void	paused(Handler<AsyncResult<Set<TopicPartition>>> handler) Get the set of partitions that were previously paused by a call to pause(Set).
void	poll(java.time.Duration timeout, Handler<AsyncResult<KafkaConsumerRecords<K,V>>> handler) Executes a poll for getting messages from Kafka.
void	poll(long timeout, Handler<AsyncResult<KafkaConsumerRecords<K,V>>> handler) Deprecated. use poll(Duration, Handler)
KafkaConsumer<K,V>	pollTimeout(java.time.Duration timeout) Sets the poll timeout for the underlying native Kafka Consumer.
KafkaConsumer<K,V>	pollTimeout(long timeout) Deprecated. use pollTimeout(Duration)
void	position(TopicPartition partition, Handler<AsyncResult<Long>> handler) Get the offset of the next record that will be fetched (if a record with that offset exists).
KafkaConsumer<K,V>	resume() Resume reading, and sets the buffer in flowing mode.
KafkaConsumer<K,V>	resume(Set<TopicPartition> topicPartitions) Resume specified partitions which have been paused with pause.
KafkaConsumer<K,V>	resume(Set<TopicPartition> topicPartitions, Handler<AsyncResult<Void>> completionHandler) Resume specified partitions which have been paused with pause.
KafkaConsumer<K,V>	resume(TopicPartition topicPartition) Resume specified partition which have been paused with pause.
KafkaConsumer<K,V>	resume(TopicPartition topicPartition, Handler<AsyncResult<Void>> completionHandler) Resume specified partition which have been paused with pause.
KafkaConsumer<K,V>	seek(TopicPartition topicPartition, long offset) Overrides the fetch offsets that the consumer will use on the next poll.
KafkaConsumer<K,V>	seek(TopicPartition topicPartition, long offset, Handler<AsyncResult<Void>> completionHandler) Overrides the fetch offsets that the consumer will use on the next poll.
KafkaConsumer<K,V>	seekToBeginning(Set<TopicPartition> topicPartitions) Seek to the first offset for each of the given partitions.
KafkaConsumer<K,V>	seekToBeginning(Set<TopicPartition> topicPartitions, Handler<AsyncResult<Void>> completionHandler) Seek to the first offset for each of the given partitions.
KafkaConsumer<K,V>	seekToBeginning(TopicPartition topicPartition) Seek to the first offset for each of the given partition.
KafkaConsumer<K,V>	seekToBeginning(TopicPartition topicPartition, Handler<AsyncResult<Void>> completionHandler) Seek to the first offset for each of the given partition.
KafkaConsumer<K,V>	seekToEnd(Set<TopicPartition> topicPartitions) Seek to the last offset for each of the given partitions.
KafkaConsumer<K,V>	seekToEnd(Set<TopicPartition> topicPartitions, Handler<AsyncResult<Void>> completionHandler) Seek to the last offset for each of the given partitions.
KafkaConsumer<K,V>	seekToEnd(TopicPartition topicPartition) Seek to the last offset for each of the given partition.
KafkaConsumer<K,V>	seekToEnd(TopicPartition topicPartition, Handler<AsyncResult<Void>> completionHandler) Seek to the last offset for each of the given partition.
KafkaConsumer<K,V>	subscribe(Pattern pattern) Subscribe to all topics matching specified pattern to get dynamically assigned partitions.
KafkaConsumer<K,V>	subscribe(Pattern pattern, Handler<AsyncResult<Void>> completionHandler) Subscribe to all topics matching specified pattern to get dynamically assigned partitions.
KafkaConsumer<K,V>	subscribe(Set<String> topics) Subscribe to the given list of topics to get dynamically assigned partitions.
KafkaConsumer<K,V>	subscribe(Set<String> topics, Handler<AsyncResult<Void>> completionHandler) Subscribe to the given list of topics to get dynamically assigned partitions.
KafkaConsumer<K,V>	subscribe(String topic) Subscribe to the given topic to get dynamically assigned partitions.
KafkaConsumer<K,V>	subscribe(String topic, Handler<AsyncResult<Void>> completionHandler) Subscribe to the given topic to get dynamically assigned partitions.
KafkaConsumer<K,V>	subscription(Handler<AsyncResult<Set<String>>> handler) Get the current subscription.
KafkaConsumer<K,V>	unsubscribe() Unsubscribe from topics currently subscribed with subscribe.
KafkaConsumer<K,V>	unsubscribe(Handler<AsyncResult<Void>> completionHandler) Unsubscribe from topics currently subscribed with subscribe.
org.apache.kafka.clients.consumer.Consumer<K,V>	unwrap()

Methods inherited from interface io.vertx.core.streams.ReadStream

pipe, pipeTo, pipeTo

Method Detail

create

static <K,V> KafkaConsumer<K,V> create(Vertx vertx,
                                       org.apache.kafka.clients.consumer.Consumer<K,V> consumer)

Create a new KafkaConsumer instance from a native Consumer.

Parameters:

vertx - Vert.x instance to use

consumer - the Kafka consumer to wrap

Returns:

an instance of the KafkaConsumer

create

static <K,V> KafkaConsumer<K,V> create(Vertx vertx,
                                       Map<String,String> config)

Create a new KafkaConsumer instance

Parameters:

vertx - Vert.x instance to use

config - Kafka consumer configuration

Returns:

an instance of the KafkaConsumer

create

static <K,V> KafkaConsumer<K,V> create(Vertx vertx,
                                       Map<String,String> config,
                                       Class<K> keyType,
                                       Class<V> valueType)

Create a new KafkaConsumer instance

Parameters:

vertx - Vert.x instance to use

config - Kafka consumer configuration

keyType - class type for the key deserialization

valueType - class type for the value deserialization

Returns:

an instance of the KafkaConsumer

create

static <K,V> KafkaConsumer<K,V> create(Vertx vertx,
                                       Map<String,String> config,
                                       org.apache.kafka.common.serialization.Deserializer<K> keyDeserializer,
                                       org.apache.kafka.common.serialization.Deserializer<V> valueDeserializer)

Create a new KafkaConsumer instance

Parameters:

vertx - Vert.x instance to use

config - Kafka consumer configuration

keyDeserializer - key deserializer

valueDeserializer - value deserializer

Returns:

an instance of the KafkaConsumer

create

static <K,V> KafkaConsumer<K,V> create(Vertx vertx,
                                       Properties config)

Create a new KafkaConsumer instance

Parameters:

vertx - Vert.x instance to use

config - Kafka consumer configuration

Returns:

an instance of the KafkaConsumer

create

static <K,V> KafkaConsumer<K,V> create(Vertx vertx,
                                       Properties config,
                                       Class<K> keyType,
                                       Class<V> valueType)

Create a new KafkaConsumer instance

Parameters:

vertx - Vert.x instance to use

config - Kafka consumer configuration

keyType - class type for the key deserialization

valueType - class type for the value deserialization

Returns:

an instance of the KafkaConsumer

create

static <K,V> KafkaConsumer<K,V> create(Vertx vertx,
                                       Properties config,
                                       org.apache.kafka.common.serialization.Deserializer<K> keyDeserializer,
                                       org.apache.kafka.common.serialization.Deserializer<V> valueDeserializer)

Create a new KafkaConsumer instance

Parameters:

vertx - Vert.x instance to use

config - Kafka consumer configuration

keyDeserializer - key deserializer

valueDeserializer - value deserializer

Returns:

an instance of the KafkaConsumer

exceptionHandler

KafkaConsumer<K,V> exceptionHandler(Handler<Throwable> handler)

Description copied from interface: ReadStream

Set an exception handler on the read stream.

Specified by:

exceptionHandler in interface ReadStream<KafkaConsumerRecord<K,V>>

Specified by:

exceptionHandler in interface StreamBase

Parameters:

handler - the exception handler

Returns:

a reference to this, so the API can be used fluently

handler

KafkaConsumer<K,V> handler(Handler<KafkaConsumerRecord<K,V>> handler)

Description copied from interface: ReadStream

Set a data handler. As data is read, the handler will be called with the data.

Specified by:

handler in interface ReadStream<KafkaConsumerRecord<K,V>>

Returns:

a reference to this, so the API can be used fluently

pause

KafkaConsumer<K,V> pause()

Description copied from interface: ReadStream

Pause the ReadStream, it sets the buffer in fetch mode and clears the actual demand.

While it's paused, no data will be sent to the data handler.

Specified by:

pause in interface ReadStream<KafkaConsumerRecord<K,V>>

Returns:

a reference to this, so the API can be used fluently

resume

KafkaConsumer<K,V> resume()

Description copied from interface: ReadStream

Resume reading, and sets the buffer in flowing mode.

If the ReadStream has been paused, reading will recommence on it.

Specified by:

resume in interface ReadStream<KafkaConsumerRecord<K,V>>

Returns:

a reference to this, so the API can be used fluently

endHandler

KafkaConsumer<K,V> endHandler(Handler<Void> endHandler)

Description copied from interface: ReadStream

Set an end handler. Once the stream has ended, and there is no more data to be read, this handler will be called.

Specified by:

endHandler in interface ReadStream<KafkaConsumerRecord<K,V>>

Returns:

a reference to this, so the API can be used fluently

fetch

KafkaConsumer<K,V> fetch(long amount)

Description copied from interface: ReadStream

Fetch the specified amount of elements. If the ReadStream has been paused, reading will recommence with the specified amount of items, otherwise the specified amount will be added to the current stream demand.

Specified by:

fetch in interface ReadStream<KafkaConsumerRecord<K,V>>

Returns:

a reference to this, so the API can be used fluently

demand

long demand()

Returns the current demand.

If the stream is in flowing mode will return Long.MAX_VALUE.
• If the stream is in fetch mode, will return the current number of elements still to be delivered or 0 if paused.

Returns:

current demand

subscribe

KafkaConsumer<K,V> subscribe(String topic)

Subscribe to the given topic to get dynamically assigned partitions.

Parameters:

topic - topic to subscribe to

Returns:

current KafkaConsumer instance

subscribe

KafkaConsumer<K,V> subscribe(Set<String> topics)

Subscribe to the given list of topics to get dynamically assigned partitions.

Parameters:

topics - topics to subscribe to

Returns:

current KafkaConsumer instance

subscribe

KafkaConsumer<K,V> subscribe(String topic,
                             Handler<AsyncResult<Void>> completionHandler)

Subscribe to the given topic to get dynamically assigned partitions.

Due to internal buffering of messages, when changing the subscribed topic the old topic may remain in effect (as observed by the handler(Handler) record handler}) until some time after the given completionHandler is called. In contrast, the once the given completionHandler is called the batchHandler(Handler) will only see messages consistent with the new topic.

Parameters:

topic - topic to subscribe to

completionHandler - handler called on operation completed

Returns:

current KafkaConsumer instance

subscribe

KafkaConsumer<K,V> subscribe(Set<String> topics,
                             Handler<AsyncResult<Void>> completionHandler)

Subscribe to the given list of topics to get dynamically assigned partitions.

Due to internal buffering of messages, when changing the subscribed topics the old set of topics may remain in effect (as observed by the handler(Handler) record handler}) until some time after the given completionHandler is called. In contrast, the once the given completionHandler is called the batchHandler(Handler) will only see messages consistent with the new set of topics.

Parameters:

topics - topics to subscribe to

completionHandler - handler called on operation completed

Returns:

current KafkaConsumer instance

subscribe

KafkaConsumer<K,V> subscribe(Pattern pattern)

Subscribe to all topics matching specified pattern to get dynamically assigned partitions.

Parameters:

pattern - Pattern to subscribe to

Returns:

current KafkaConsumer instance

subscribe

KafkaConsumer<K,V> subscribe(Pattern pattern,
                             Handler<AsyncResult<Void>> completionHandler)

Subscribe to all topics matching specified pattern to get dynamically assigned partitions.

Due to internal buffering of messages, when changing the subscribed topics the old set of topics may remain in effect (as observed by the handler(Handler) record handler}) until some time after the given completionHandler is called. In contrast, the once the given completionHandler is called the batchHandler(Handler) will only see messages consistent with the new set of topics.

Parameters:

pattern - Pattern to subscribe to

completionHandler - handler called on operation completed

Returns:

current KafkaConsumer instance

assign

KafkaConsumer<K,V> assign(TopicPartition topicPartition)

Manually assign a partition to this consumer.

Parameters:

topicPartition - partition which want assigned

Returns:

current KafkaConsumer instance

assign

KafkaConsumer<K,V> assign(Set<TopicPartition> topicPartitions)

Manually assign a list of partition to this consumer.

Parameters:

topicPartitions - partitions which want assigned

Returns:

current KafkaConsumer instance

assign

KafkaConsumer<K,V> assign(TopicPartition topicPartition,
                          Handler<AsyncResult<Void>> completionHandler)

Manually assign a partition to this consumer.

Due to internal buffering of messages, when reassigning the old partition may remain in effect (as observed by the handler(Handler) record handler)} until some time after the given completionHandler is called. In contrast, the once the given completionHandler is called the batchHandler(Handler) will only see messages consistent with the new partition.

Parameters:

topicPartition - partition which want assigned

completionHandler - handler called on operation completed

Returns:

current KafkaConsumer instance

assign

KafkaConsumer<K,V> assign(Set<TopicPartition> topicPartitions,
                          Handler<AsyncResult<Void>> completionHandler)

Manually assign a list of partition to this consumer.

Due to internal buffering of messages, when reassigning the old set of partitions may remain in effect (as observed by the handler(Handler) record handler)} until some time after the given completionHandler is called. In contrast, the once the given completionHandler is called the batchHandler(Handler) will only see messages consistent with the new set of partitions.

Parameters:

topicPartitions - partitions which want assigned

completionHandler - handler called on operation completed

Returns:

current KafkaConsumer instance

assignment

KafkaConsumer<K,V> assignment(Handler<AsyncResult<Set<TopicPartition>>> handler)

Get the set of partitions currently assigned to this consumer.

Parameters:

handler - handler called on operation completed

Returns:

current KafkaConsumer instance

listTopics

KafkaConsumer<K,V> listTopics(Handler<AsyncResult<Map<String,List<PartitionInfo>>>> handler)

Get metadata about partitions for all topics that the user is authorized to view.

Parameters:

handler - handler called on operation completed

Returns:

current KafkaConsumer instance

unsubscribe

KafkaConsumer<K,V> unsubscribe()

Unsubscribe from topics currently subscribed with subscribe.

Returns:

current KafkaConsumer instance

unsubscribe

KafkaConsumer<K,V> unsubscribe(Handler<AsyncResult<Void>> completionHandler)

Unsubscribe from topics currently subscribed with subscribe.

Parameters:

completionHandler - handler called on operation completed

Returns:

current KafkaConsumer instance

subscription

KafkaConsumer<K,V> subscription(Handler<AsyncResult<Set<String>>> handler)

Get the current subscription.

Parameters:

handler - handler called on operation completed

Returns:

current KafkaConsumer instance

pause

KafkaConsumer<K,V> pause(TopicPartition topicPartition)

Suspend fetching from the requested partition.

Parameters:

topicPartition - topic partition from which suspend fetching

Returns:

current KafkaConsumer instance

pause

KafkaConsumer<K,V> pause(Set<TopicPartition> topicPartitions)

Suspend fetching from the requested partitions.

Parameters:

topicPartitions - topic partition from which suspend fetching

Returns:

current KafkaConsumer instance

pause

KafkaConsumer<K,V> pause(TopicPartition topicPartition,
                         Handler<AsyncResult<Void>> completionHandler)

Suspend fetching from the requested partition.

Due to internal buffering of messages, the record handler will continue to observe messages from the given topicPartition until some time after the given completionHandler is called. In contrast, the once the given completionHandler is called the batchHandler(Handler) will not see messages from the given topicPartition.

Parameters:

topicPartition - topic partition from which suspend fetching

completionHandler - handler called on operation completed

Returns:

current KafkaConsumer instance

pause

KafkaConsumer<K,V> pause(Set<TopicPartition> topicPartitions,
                         Handler<AsyncResult<Void>> completionHandler)

Suspend fetching from the requested partitions.

Due to internal buffering of messages, the record handler will continue to observe messages from the given topicPartitions until some time after the given completionHandler is called. In contrast, the once the given completionHandler is called the batchHandler(Handler) will not see messages from the given topicPartitions.

Parameters:

topicPartitions - topic partition from which suspend fetching

completionHandler - handler called on operation completed

Returns:

current KafkaConsumer instance

paused

void paused(Handler<AsyncResult<Set<TopicPartition>>> handler)

Get the set of partitions that were previously paused by a call to pause(Set).

Parameters:

handler - handler called on operation completed

resume

KafkaConsumer<K,V> resume(TopicPartition topicPartition)

Resume specified partition which have been paused with pause.

Parameters:

topicPartition - topic partition from which resume fetching

Returns:

current KafkaConsumer instance

resume

KafkaConsumer<K,V> resume(Set<TopicPartition> topicPartitions)

Resume specified partitions which have been paused with pause.

Parameters:

topicPartitions - topic partition from which resume fetching

Returns:

current KafkaConsumer instance

resume

KafkaConsumer<K,V> resume(TopicPartition topicPartition,
                          Handler<AsyncResult<Void>> completionHandler)

Resume specified partition which have been paused with pause.

Parameters:

topicPartition - topic partition from which resume fetching

completionHandler - handler called on operation completed

Returns:

current KafkaConsumer instance

resume

KafkaConsumer<K,V> resume(Set<TopicPartition> topicPartitions,
                          Handler<AsyncResult<Void>> completionHandler)

Resume specified partitions which have been paused with pause.

Parameters:

topicPartitions - topic partition from which resume fetching

completionHandler - handler called on operation completed

Returns:

current KafkaConsumer instance

partitionsRevokedHandler

KafkaConsumer<K,V> partitionsRevokedHandler(Handler<Set<TopicPartition>> handler)

Set the handler called when topic partitions are revoked to the consumer

Parameters:

handler - handler called on revoked topic partitions

Returns:

current KafkaConsumer instance

partitionsAssignedHandler

KafkaConsumer<K,V> partitionsAssignedHandler(Handler<Set<TopicPartition>> handler)

Set the handler called when topic partitions are assigned to the consumer

Parameters:

handler - handler called on assigned topic partitions

Returns:

current KafkaConsumer instance

seek

KafkaConsumer<K,V> seek(TopicPartition topicPartition,
                        long offset)

Overrides the fetch offsets that the consumer will use on the next poll.

Parameters:

topicPartition - topic partition for which seek

offset - offset to seek inside the topic partition

Returns:

current KafkaConsumer instance

seek

KafkaConsumer<K,V> seek(TopicPartition topicPartition,
                        long offset,
                        Handler<AsyncResult<Void>> completionHandler)

Overrides the fetch offsets that the consumer will use on the next poll.

Due to internal buffering of messages, the record handler will continue to observe messages fetched with respect to the old offset until some time after the given completionHandler is called. In contrast, the once the given completionHandler is called the batchHandler(Handler) will only see messages consistent with the new offset.

Parameters:

topicPartition - topic partition for which seek

offset - offset to seek inside the topic partition

completionHandler - handler called on operation completed

Returns:

current KafkaConsumer instance

seekToBeginning

KafkaConsumer<K,V> seekToBeginning(TopicPartition topicPartition)

Seek to the first offset for each of the given partition.

Parameters:

topicPartition - topic partition for which seek

Returns:

current KafkaConsumer instance

seekToBeginning

KafkaConsumer<K,V> seekToBeginning(Set<TopicPartition> topicPartitions)

Seek to the first offset for each of the given partitions.

Parameters:

topicPartitions - topic partition for which seek

Returns:

current KafkaConsumer instance

seekToBeginning

KafkaConsumer<K,V> seekToBeginning(TopicPartition topicPartition,
                                   Handler<AsyncResult<Void>> completionHandler)

Seek to the first offset for each of the given partition.

Due to internal buffering of messages, the record handler will continue to observe messages fetched with respect to the old offset until some time after the given completionHandler is called. In contrast, the once the given completionHandler is called the batchHandler(Handler) will only see messages consistent with the new offset.

Parameters:

topicPartition - topic partition for which seek

completionHandler - handler called on operation completed

Returns:

current KafkaConsumer instance

seekToBeginning

KafkaConsumer<K,V> seekToBeginning(Set<TopicPartition> topicPartitions,
                                   Handler<AsyncResult<Void>> completionHandler)

Seek to the first offset for each of the given partitions.

Due to internal buffering of messages, the record handler will continue to observe messages fetched with respect to the old offset until some time after the given completionHandler is called. In contrast, the once the given completionHandler is called the batchHandler(Handler) will only see messages consistent with the new offset.

Parameters:

topicPartitions - topic partition for which seek

completionHandler - handler called on operation completed

Returns:

current KafkaConsumer instance

seekToEnd

KafkaConsumer<K,V> seekToEnd(TopicPartition topicPartition)

Seek to the last offset for each of the given partition.

Parameters:

topicPartition - topic partition for which seek

Returns:

current KafkaConsumer instance

seekToEnd

KafkaConsumer<K,V> seekToEnd(Set<TopicPartition> topicPartitions)

Seek to the last offset for each of the given partitions.

Parameters:

topicPartitions - topic partition for which seek

Returns:

current KafkaConsumer instance

seekToEnd

KafkaConsumer<K,V> seekToEnd(TopicPartition topicPartition,
                             Handler<AsyncResult<Void>> completionHandler)

Seek to the last offset for each of the given partition.

Due to internal buffering of messages, the record handler will continue to observe messages fetched with respect to the old offset until some time after the given completionHandler is called. In contrast, the once the given completionHandler is called the batchHandler(Handler) will only see messages consistent with the new offset.

Parameters:

topicPartition - topic partition for which seek

completionHandler - handler called on operation completed

Returns:

current KafkaConsumer instance

seekToEnd

KafkaConsumer<K,V> seekToEnd(Set<TopicPartition> topicPartitions,
                             Handler<AsyncResult<Void>> completionHandler)

Seek to the last offset for each of the given partitions.

Due to internal buffering of messages, the record handler will continue to observe messages fetched with respect to the old offset until some time after the given completionHandler is called. In contrast, the once the given completionHandler is called the batchHandler(Handler) will only see messages consistent with the new offset.

Parameters:

topicPartitions - topic partition for which seek

completionHandler - handler called on operation completed

Returns:

current KafkaConsumer instance

commit

void commit()

Commit current offsets for all the subscribed list of topics and partition.

commit

void commit(Handler<AsyncResult<Void>> completionHandler)

Commit current offsets for all the subscribed list of topics and partition.

Parameters:

completionHandler - handler called on operation completed

commit

void commit(Map<TopicPartition,OffsetAndMetadata> offsets)

Commit the specified offsets for the specified list of topics and partitions to Kafka.

Parameters:

offsets - offsets list to commit

commit

void commit(Map<TopicPartition,OffsetAndMetadata> offsets,
            Handler<AsyncResult<Map<TopicPartition,OffsetAndMetadata>>> completionHandler)

Commit the specified offsets for the specified list of topics and partitions to Kafka.

Parameters:

offsets - offsets list to commit

completionHandler - handler called on operation completed

committed

void committed(TopicPartition topicPartition,
               Handler<AsyncResult<OffsetAndMetadata>> handler)

Get the last committed offset for the given partition (whether the commit happened by this process or another).

Parameters:

topicPartition - topic partition for getting last committed offset

handler - handler called on operation completed

partitionsFor

KafkaConsumer<K,V> partitionsFor(String topic,
                                 Handler<AsyncResult<List<PartitionInfo>>> handler)

Get metadata about the partitions for a given topic.

Parameters:

topic - topic partition for which getting partitions info

handler - handler called on operation completed

Returns:

current KafkaConsumer instance

batchHandler

KafkaConsumer<K,V> batchHandler(Handler<KafkaConsumerRecords<K,V>> handler)

Set the handler to be used when batches of messages are fetched from the Kafka server. Batch handlers need to take care not to block the event loop when dealing with large batches. It is better to process records individually using the record handler.

Parameters:

handler - handler called when batches of messages are fetched

Returns:

current KafkaConsumer instance

close

default void close()

Close the consumer

close

void close(Handler<AsyncResult<Void>> completionHandler)

Close the consumer

Parameters:

completionHandler - handler called on operation completed

position

void position(TopicPartition partition,
              Handler<AsyncResult<Long>> handler)

Get the offset of the next record that will be fetched (if a record with that offset exists).

Parameters:

partition - The partition to get the position for

handler - handler called on operation completed

offsetsForTimes

void offsetsForTimes(Map<TopicPartition,Long> topicPartitionTimestamps,
                     Handler<AsyncResult<Map<TopicPartition,OffsetAndTimestamp>>> handler)

Look up the offsets for the given partitions by timestamp. Note: the result might be empty in case for the given timestamp no offset can be found -- e.g., when the timestamp refers to the future

Parameters:

topicPartitionTimestamps - A map with pairs of (TopicPartition, Timestamp).

handler - handler called on operation completed

offsetsForTimes

void offsetsForTimes(TopicPartition topicPartition,
                     Long timestamp,
                     Handler<AsyncResult<OffsetAndTimestamp>> handler)

Look up the offset for the given partition by timestamp. Note: the result might be null in case for the given timestamp no offset can be found -- e.g., when the timestamp refers to the future

Parameters:

topicPartition - TopicPartition to query.

timestamp - Timestamp to be used in the query.

handler - handler called on operation completed

beginningOffsets

void beginningOffsets(Set<TopicPartition> topicPartitions,
                      Handler<AsyncResult<Map<TopicPartition,Long>>> handler)

Get the first offset for the given partitions.

Parameters:

topicPartitions - the partitions to get the earliest offsets.

handler - handler called on operation completed. Returns the earliest available offsets for the given partitions

beginningOffsets

void beginningOffsets(TopicPartition topicPartition,
                      Handler<AsyncResult<Long>> handler)

Get the first offset for the given partitions.

Parameters:

topicPartition - the partition to get the earliest offset.

handler - handler called on operation completed. Returns the earliest available offset for the given partition

endOffsets

void endOffsets(Set<TopicPartition> topicPartitions,
                Handler<AsyncResult<Map<TopicPartition,Long>>> handler)

Get the last offset for the given partitions. The last offset of a partition is the offset of the upcoming message, i.e. the offset of the last available message + 1.

Parameters:

topicPartitions - the partitions to get the end offsets.

handler - handler called on operation completed. The end offsets for the given partitions.

endOffsets

void endOffsets(TopicPartition topicPartition,
                Handler<AsyncResult<Long>> handler)

Get the last offset for the given partition. The last offset of a partition is the offset of the upcoming message, i.e. the offset of the last available message + 1.

Parameters:

topicPartition - the partition to get the end offset.

handler - handler called on operation completed. The end offset for the given partition.

asStream

KafkaReadStream<K,V> asStream()

Returns:

underlying the KafkaReadStream instance

unwrap

org.apache.kafka.clients.consumer.Consumer<K,V> unwrap()

Returns:

the underlying consumer

pollTimeout

@Deprecated
KafkaConsumer<K,V> pollTimeout(long timeout)

Deprecated. use pollTimeout(Duration)

Sets the poll timeout (in ms) for the underlying native Kafka Consumer. Defaults to 1000.

pollTimeout

KafkaConsumer<K,V> pollTimeout(java.time.Duration timeout)

Sets the poll timeout for the underlying native Kafka Consumer. Defaults to 1000ms. Setting timeout to a lower value results in a more 'responsive' client, because it will block for a shorter period if no data is available in the assigned partition and therefore allows subsequent actions to be executed with a shorter delay. At the same time, the client will poll more frequently and thus will potentially create a higher load on the Kafka Broker.

Parameters:

timeout - The time, spent waiting in poll if data is not available in the buffer. If 0, returns immediately with any records that are available currently in the native Kafka consumer's buffer, else returns empty. Must not be negative.

poll

@Deprecated
void poll(long timeout,
                      Handler<AsyncResult<KafkaConsumerRecords<K,V>>> handler)

Deprecated. use poll(Duration, Handler)

Executes a poll for getting messages from Kafka

Parameters:

timeout - The time, in milliseconds, spent waiting in poll if data is not available in the buffer. If 0, returns immediately with any records that are available currently in the native Kafka consumer's buffer, else returns empty. Must not be negative.

handler - handler called after the poll with batch of records (can be empty).

poll

void poll(java.time.Duration timeout,
          Handler<AsyncResult<KafkaConsumerRecords<K,V>>> handler)

Executes a poll for getting messages from Kafka.

Parameters:

timeout - The maximum time to block (must not be greater than Long.MAX_VALUE milliseconds)

handler - handler called after the poll with batch of records (can be empty).