Module io.helidon.messaging.connectors.kafka

Package io.helidon.messaging.connectors.kafka

Class KafkaPublisher.Builder<K,V>

java.lang.Object

io.helidon.messaging.connectors.kafka.KafkaPublisher.Builder<K,V>

Type Parameters:

K - Key type

V - Value type

All Implemented Interfaces:

Builder<KafkaPublisher<K,V>>, Supplier<KafkaPublisher<K,V>>

Enclosing class:

KafkaPublisher<K,V>

public static final class KafkaPublisher.Builder<K,V>
extends Object
implements Builder<KafkaPublisher<K,V>>

Fluent API builder for KafkaPublisher.

Method Summary

Modifier and Type	Method	Description
KafkaPublisher.Builder<K,V>	ackTimeout(long ackTimeout)	This value applies only when autoCommit is set to false.
KafkaPublisher.Builder<K,V>	autoCommit(boolean autoCommit)	This flag defines the strategy of committing messages to Kafka.
KafkaPublisher<K,V>	build()	Build the instance from this builder.
KafkaPublisher.Builder<K,V>	config(Config config)	Load this builder from a configuration.
KafkaPublisher.Builder<K,V>	consumerSupplier(Supplier<org.apache.kafka.clients.consumer.Consumer<K,V>> consumerSupplier)	Defines how to instantiate the KafkaConsumer.
KafkaPublisher.Builder<K,V>	limitNoAck(int limitNoAck)	This value applies only when autoCommit is set to false.
KafkaPublisher.Builder<K,V>	periodExecutions(long periodExecutions)	Specifies the period in milliseconds between successive scheduler executions.
KafkaPublisher.Builder<K,V>	pollTimeout(long pollTimeout)	Specifies maximum time in milliseconds to block polling messages from Kafka.
KafkaPublisher.Builder<K,V>	scheduler(ScheduledExecutorService scheduler)	Specify a scheduler that will read ad process messages coming from Kafka.
KafkaPublisher.Builder<K,V>	topicPattern(Pattern topicPattern)	The pattern for selecting multiple topics.
KafkaPublisher.Builder<K,V>	topics(List<String> topics)	The list of topics to subscribe to.

Methods inherited from class java.lang.Object

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

Methods inherited from interface io.helidon.common.Builder

get

Method Detail

config

public KafkaPublisher.Builder<K,V> config(Config config)

Load this builder from a configuration.

Parameters:

config - configuration to load from

Returns:

updated builder instance

consumerSupplier

public KafkaPublisher.Builder<K,V> consumerSupplier(Supplier<org.apache.kafka.clients.consumer.Consumer<K,V>> consumerSupplier)

Defines how to instantiate the KafkaConsumer. It will be invoked in KafkaPublisher.subscribe(Subscriber) This is a mandatory parameter.

Parameters:

consumerSupplier - instantiated Kafka consumer

Returns:

updated builder instance

topics

public KafkaPublisher.Builder<K,V> topics(List<String> topics)

The list of topics to subscribe to. This is a mandatory parameter if topicPattern is empty.

Parameters:

topics - list of topics to subscribe to

Returns:

updated builder instance

topicPattern

public KafkaPublisher.Builder<K,V> topicPattern(Pattern topicPattern)

The pattern for selecting multiple topics. This is a mandatory parameter if topics is empty.

Parameters:

topicPattern - pattern for selecting multiple topics

Returns:

updated builder instance

scheduler

public KafkaPublisher.Builder<K,V> scheduler(ScheduledExecutorService scheduler)

Specify a scheduler that will read ad process messages coming from Kafka. Is it intended that this scheduler is reused for other tasks. This is a mandatory parameter.

Parameters:

scheduler - scheduler that will read ad process messages

Returns:

updated builder instance

periodExecutions

public KafkaPublisher.Builder<K,V> periodExecutions(long periodExecutions)

Specifies the period in milliseconds between successive scheduler executions. The default value is 100 milliseconds.

Parameters:

periodExecutions - period in milliseconds

Returns:

updated builder instance

pollTimeout

public KafkaPublisher.Builder<K,V> pollTimeout(long pollTimeout)

Specifies maximum time in milliseconds to block polling messages from Kafka. The default value is 50 milliseconds.

Parameters:

pollTimeout - maximum time in milliseconds to block polling

Returns:

updated builder instance

autoCommit

public KafkaPublisher.Builder<K,V> autoCommit(boolean autoCommit)

This flag defines the strategy of committing messages to Kafka. When true, the messages are committed at the moment they are polled from Kafka. When false, the messages are committed when Message.ack() is invoked. This value is mandatory to be specified, and it must be consistent with the value enable.auto.commit in Kafka properties. Failing to do this will result the next scenarios: - For autoCommit = true and enable.auto.commit = false, messages will never be committed in Kafka. - For autoCommit = false and enable.auto.commit = true, all messages will be committed and Message.ack() will have no effect.

Parameters:

autoCommit - strategy of committing

Returns:

updated builder instance

ackTimeout

public KafkaPublisher.Builder<K,V> ackTimeout(long ackTimeout)

This value applies only when autoCommit is set to false. It defines the maximum time in milliseconds that Message.ack() will be waiting for the commit in Kafka. The default value is Long.MAX_VALUE

Parameters:

ackTimeout - time in milliseconds

Returns:

updated builder instance

limitNoAck

public KafkaPublisher.Builder<K,V> limitNoAck(int limitNoAck)

This value applies only when autoCommit is set to false. It specifies the limit of messages waiting to be committed in Kafka. If this value is overflown, the KafkaPublisher will notify a failure. The intention of this value is to fail gracefully when there are many pending commits, instead of failing with OutOfMemoryError.

Parameters:

limitNoAck - limit of messages waiting to be committed

Returns:

updated builder instance

build

public KafkaPublisher<K,V> build()

Description copied from interface: Builder

Build the instance from this builder.

Specified by:

build in interface Builder<K>

Returns:

instance of the built type