org.springframework.kafka.core

Class KafkaTemplate<K,V>

java.lang.Object

org.springframework.kafka.core.KafkaTemplate<K,V>

Type Parameters:

K - the key type.

V - the value type.

All Implemented Interfaces:

KafkaOperations<K,V>

Direct Known Subclasses:

ReplyingKafkaTemplate

public class KafkaTemplate<K,V>
extends java.lang.Object
implements KafkaOperations<K,V>

A template for executing high-level operations.

Author:

Marius Bogoevici, Gary Russell, Igor Stepanov, Artem Bilan, Biju Kunjummen

Nested Class Summary

Nested classes/interfaces inherited from interface org.springframework.kafka.core.KafkaOperations

KafkaOperations.OperationsCallback<K,V,T>, KafkaOperations.ProducerCallback<K,V,T>

Field Summary

Fields

Modifier and Type	Field and Description
protected org.apache.commons.logging.Log	logger

Constructor Summary

Constructors

Constructor and Description
KafkaTemplate(ProducerFactory<K,V> producerFactory) Create an instance using the supplied producer factory and autoFlush false.
KafkaTemplate(ProducerFactory<K,V> producerFactory, boolean autoFlush) Create an instance using the supplied producer factory and autoFlush setting.

Method Summary

Modifier and Type	Method and Description
protected void	closeProducer(org.apache.kafka.clients.producer.Producer<K,V> producer, boolean inLocalTx)
protected org.springframework.util.concurrent.ListenableFuture<SendResult<K,V>>	doSend(org.apache.kafka.clients.producer.ProducerRecord<K,V> producerRecord) Send the producer record.
<T> T	execute(KafkaOperations.ProducerCallback<K,V,T> callback) Execute some arbitrary operation(s) on the producer and return the result.
<T> T	executeInTransaction(KafkaOperations.OperationsCallback<K,V,T> callback) Execute some arbitrary operation(s) on the operations and return the result.
void	flush() Flush the producer.
java.lang.String	getDefaultTopic() The default topic for send methods where a topic is not provided.
MessageConverter	getMessageConverter() Return the message converter.
protected boolean	inTransaction()
boolean	isTransactional() Return true if this template supports transactions (has a transaction-capable producer factory).
java.util.Map<org.apache.kafka.common.MetricName,? extends org.apache.kafka.common.Metric>	metrics() See Producer.metrics().
java.util.List<org.apache.kafka.common.PartitionInfo>	partitionsFor(java.lang.String topic) See Producer.partitionsFor(String).
org.springframework.util.concurrent.ListenableFuture<SendResult<K,V>>	send(org.springframework.messaging.Message<?> message) Send a message with routing information in message headers.
org.springframework.util.concurrent.ListenableFuture<SendResult<K,V>>	send(org.apache.kafka.clients.producer.ProducerRecord<K,V> record) Send the provided ProducerRecord.
org.springframework.util.concurrent.ListenableFuture<SendResult<K,V>>	send(java.lang.String topic, java.lang.Integer partition, K key, V data) Send the data to the provided topic with the provided key and partition.
org.springframework.util.concurrent.ListenableFuture<SendResult<K,V>>	send(java.lang.String topic, java.lang.Integer partition, java.lang.Long timestamp, K key, V data) Send the data to the provided topic with the provided key and partition.
org.springframework.util.concurrent.ListenableFuture<SendResult<K,V>>	send(java.lang.String topic, K key, V data) Send the data to the provided topic with the provided key and no partition.
org.springframework.util.concurrent.ListenableFuture<SendResult<K,V>>	send(java.lang.String topic, V data) Send the data to the provided topic with no key or partition.
org.springframework.util.concurrent.ListenableFuture<SendResult<K,V>>	sendDefault(java.lang.Integer partition, K key, V data) Send the data to the default topic with the provided key and partition.
org.springframework.util.concurrent.ListenableFuture<SendResult<K,V>>	sendDefault(java.lang.Integer partition, java.lang.Long timestamp, K key, V data) Send the data to the default topic with the provided key and partition.
org.springframework.util.concurrent.ListenableFuture<SendResult<K,V>>	sendDefault(K key, V data) Send the data to the default topic with the provided key and no partition.
org.springframework.util.concurrent.ListenableFuture<SendResult<K,V>>	sendDefault(V data) Send the data to the default topic with no key or partition.
void	sendOffsetsToTransaction(java.util.Map<org.apache.kafka.common.TopicPartition,org.apache.kafka.clients.consumer.OffsetAndMetadata> offsets) When running in a transaction (usually synchronized with some other transaction), send the consumer offset(s) to the transaction.
void	sendOffsetsToTransaction(java.util.Map<org.apache.kafka.common.TopicPartition,org.apache.kafka.clients.consumer.OffsetAndMetadata> offsets, java.lang.String consumerGroupId) When running in a transaction (usually synchronized with some other transaction), send the consumer offset(s) to the transaction.
void	setDefaultTopic(java.lang.String defaultTopic) Set the default topic for send methods where a topic is not provided.
void	setMessageConverter(RecordMessageConverter messageConverter) Set the message converter to use.
void	setProducerListener(ProducerListener<K,V> producerListener) Set a ProducerListener which will be invoked when Kafka acknowledges a send operation.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

logger

protected final org.apache.commons.logging.Log logger

Constructor Detail

KafkaTemplate

public KafkaTemplate(ProducerFactory<K,V> producerFactory)

Create an instance using the supplied producer factory and autoFlush false.

Parameters:

producerFactory - the producer factory.

KafkaTemplate

public KafkaTemplate(ProducerFactory<K,V> producerFactory,
                     boolean autoFlush)

Create an instance using the supplied producer factory and autoFlush setting.

Set autoFlush to true if you have configured the producer's linger.ms to a non-default value and wish send operations on this template to occur immediately, regardless of that setting, or if you wish to block until the broker has acknowledged receipt according to the producer's acks property.

Parameters:

producerFactory - the producer factory.

autoFlush - true to flush after each send.

See Also:

Producer.flush()

Method Detail

getDefaultTopic

public java.lang.String getDefaultTopic()

The default topic for send methods where a topic is not provided.

Returns:

the topic.

setDefaultTopic

public void setDefaultTopic(java.lang.String defaultTopic)

Set the default topic for send methods where a topic is not provided.

Parameters:

defaultTopic - the topic.

setProducerListener

public void setProducerListener(ProducerListener<K,V> producerListener)

Set a ProducerListener which will be invoked when Kafka acknowledges a send operation. By default a LoggingProducerListener is configured which logs errors only.

Parameters:

producerListener - the listener; may be null.

getMessageConverter

public MessageConverter getMessageConverter()

Return the message converter.

Returns:

the message converter.

setMessageConverter

public void setMessageConverter(RecordMessageConverter messageConverter)

Set the message converter to use.

Parameters:

messageConverter - the message converter.

isTransactional

public boolean isTransactional()

Return true if this template supports transactions (has a transaction-capable producer factory).

Returns:

true or false.

Since:

2.1.3

sendDefault

public org.springframework.util.concurrent.ListenableFuture<SendResult<K,V>> sendDefault(V data)

Description copied from interface: KafkaOperations

Send the data to the default topic with no key or partition.

Specified by:

sendDefault in interface KafkaOperations<K,V>

Parameters:

data - The data.

Returns:

a Future for the SendResult.

sendDefault

public org.springframework.util.concurrent.ListenableFuture<SendResult<K,V>> sendDefault(K key,
                                                                                         V data)

Description copied from interface: KafkaOperations

Send the data to the default topic with the provided key and no partition.

Specified by:

sendDefault in interface KafkaOperations<K,V>

Parameters:

key - the key.

data - The data.

Returns:

a Future for the SendResult.

sendDefault

public org.springframework.util.concurrent.ListenableFuture<SendResult<K,V>> sendDefault(java.lang.Integer partition,
                                                                                         K key,
                                                                                         V data)

Description copied from interface: KafkaOperations

Send the data to the default topic with the provided key and partition.

Specified by:

sendDefault in interface KafkaOperations<K,V>

Parameters:

partition - the partition.

key - the key.

data - the data.

Returns:

a Future for the SendResult.

sendDefault

public org.springframework.util.concurrent.ListenableFuture<SendResult<K,V>> sendDefault(java.lang.Integer partition,
                                                                                         java.lang.Long timestamp,
                                                                                         K key,
                                                                                         V data)

Description copied from interface: KafkaOperations

Send the data to the default topic with the provided key and partition.

Specified by:

sendDefault in interface KafkaOperations<K,V>

Parameters:

partition - the partition.

timestamp - the timestamp of the record.

key - the key.

data - the data.

Returns:

a Future for the SendResult.

send

public org.springframework.util.concurrent.ListenableFuture<SendResult<K,V>> send(java.lang.String topic,
                                                                                  V data)

Description copied from interface: KafkaOperations

Send the data to the provided topic with no key or partition.

Specified by:

send in interface KafkaOperations<K,V>

Parameters:

topic - the topic.

data - The data.

Returns:

a Future for the SendResult.

send

public org.springframework.util.concurrent.ListenableFuture<SendResult<K,V>> send(java.lang.String topic,
                                                                                  K key,
                                                                                  V data)

Description copied from interface: KafkaOperations

Send the data to the provided topic with the provided key and no partition.

Specified by:

send in interface KafkaOperations<K,V>

Parameters:

topic - the topic.

key - the key.

data - The data.

Returns:

a Future for the SendResult.

send

public org.springframework.util.concurrent.ListenableFuture<SendResult<K,V>> send(java.lang.String topic,
                                                                                  java.lang.Integer partition,
                                                                                  K key,
                                                                                  V data)

Description copied from interface: KafkaOperations

Send the data to the provided topic with the provided key and partition.

Specified by:

send in interface KafkaOperations<K,V>

Parameters:

topic - the topic.

partition - the partition.

key - the key.

data - the data.

Returns:

a Future for the SendResult.

send

public org.springframework.util.concurrent.ListenableFuture<SendResult<K,V>> send(java.lang.String topic,
                                                                                  java.lang.Integer partition,
                                                                                  java.lang.Long timestamp,
                                                                                  K key,
                                                                                  V data)

Description copied from interface: KafkaOperations

Send the data to the provided topic with the provided key and partition.

Specified by:

send in interface KafkaOperations<K,V>

Parameters:

topic - the topic.

partition - the partition.

timestamp - the timestamp of the record.

key - the key.

data - the data.

Returns:

a Future for the SendResult.

send

public org.springframework.util.concurrent.ListenableFuture<SendResult<K,V>> send(org.apache.kafka.clients.producer.ProducerRecord<K,V> record)

Description copied from interface: KafkaOperations

Send the provided ProducerRecord.

Specified by:

send in interface KafkaOperations<K,V>

Parameters:

record - the record.

Returns:

a Future for the SendResult.

send

public org.springframework.util.concurrent.ListenableFuture<SendResult<K,V>> send(org.springframework.messaging.Message<?> message)

Description copied from interface: KafkaOperations

Send a message with routing information in message headers. The message payload may be converted before sending.

Specified by:

send in interface KafkaOperations<K,V>

Parameters:

message - the message to send.

Returns:

a Future for the SendResult.

See Also:

KafkaHeaders.TOPIC, KafkaHeaders.PARTITION_ID, KafkaHeaders.MESSAGE_KEY

partitionsFor

public java.util.List<org.apache.kafka.common.PartitionInfo> partitionsFor(java.lang.String topic)

Description copied from interface: KafkaOperations

See Producer.partitionsFor(String).

Specified by:

partitionsFor in interface KafkaOperations<K,V>

Parameters:

topic - the topic.

Returns:

the partition info.

metrics

public java.util.Map<org.apache.kafka.common.MetricName,? extends org.apache.kafka.common.Metric> metrics()

Description copied from interface: KafkaOperations

See Producer.metrics().

Specified by:

metrics in interface KafkaOperations<K,V>

Returns:

the metrics.

execute

public <T> T execute(KafkaOperations.ProducerCallback<K,V,T> callback)

Description copied from interface: KafkaOperations

Execute some arbitrary operation(s) on the producer and return the result.

Specified by:

execute in interface KafkaOperations<K,V>

Type Parameters:

T - the result type.

Parameters:

callback - the callback.

Returns:

the result.

executeInTransaction

public <T> T executeInTransaction(KafkaOperations.OperationsCallback<K,V,T> callback)

Description copied from interface: KafkaOperations

Execute some arbitrary operation(s) on the operations and return the result. The operations are invoked within a local transaction and do not participate in a global transaction (if present).

Specified by:

executeInTransaction in interface KafkaOperations<K,V>

Type Parameters:

T - the result type.

Parameters:

callback - the callback.

Returns:

the result.

flush

public void flush()

Flush the producer.

Note It only makes sense to invoke this method if the ProducerFactory serves up a singleton producer (such as the DefaultKafkaProducerFactory).

Specified by:

flush in interface KafkaOperations<K,V>

sendOffsetsToTransaction

public void sendOffsetsToTransaction(java.util.Map<org.apache.kafka.common.TopicPartition,org.apache.kafka.clients.consumer.OffsetAndMetadata> offsets)

Description copied from interface: KafkaOperations

When running in a transaction (usually synchronized with some other transaction), send the consumer offset(s) to the transaction. The group id is obtained from ProducerFactoryUtils.getConsumerGroupId(). It is not necessary to call this method if the operations are invoked on a listener container thread since the container will take care of sending the offsets to the transaction.

Specified by:

sendOffsetsToTransaction in interface KafkaOperations<K,V>

Parameters:

offsets - The offsets.

sendOffsetsToTransaction

public void sendOffsetsToTransaction(java.util.Map<org.apache.kafka.common.TopicPartition,org.apache.kafka.clients.consumer.OffsetAndMetadata> offsets,
                                     java.lang.String consumerGroupId)

Description copied from interface: KafkaOperations

When running in a transaction (usually synchronized with some other transaction), send the consumer offset(s) to the transaction. It is not necessary to call this method if the operations are invoked on a listener container thread since the container will take care of sending the offsets to the transaction.

Specified by:

sendOffsetsToTransaction in interface KafkaOperations<K,V>

Parameters:

offsets - The offsets.

consumerGroupId - the consumer's group.id.

closeProducer

protected void closeProducer(org.apache.kafka.clients.producer.Producer<K,V> producer,
                             boolean inLocalTx)

doSend

protected org.springframework.util.concurrent.ListenableFuture<SendResult<K,V>> doSend(org.apache.kafka.clients.producer.ProducerRecord<K,V> producerRecord)

Send the producer record.

Parameters:

producerRecord - the producer record.

Returns:

a Future for the RecordMetadata.

inTransaction

protected boolean inTransaction()