org.seedstack.kafka

Interface ConsumerListener<K,V>

public interface ConsumerListener<K,V>

Implement this interface to listen asynchronously to records using a Kafka consumer. By annotating the implementing class with KafkaListener, the underlying consumer will be automatically subscribed to the specified topics.

The underlying Kafka consumer will be automatically started and stopped with the application. A unhandled failure will gracefully stop the consumer and a later attempt will be rescheduled.

If the implementing class also implements ConsumerRebalanceListener, it will be used as the rebalance listener for the underlying consumer. If the implementing class also implements OffsetCommitCallback, it will be used as a callback during the asynchronous commits.

Method Summary

Modifier and Type	Method and Description
default void	onConsumerRecord(org.apache.kafka.clients.consumer.ConsumerRecord<K,V> record) This method is called when a ConsumerRecords is available.
default void	onConsumerRecords(org.apache.kafka.clients.consumer.ConsumerRecords<K,V> records) This method is called when some ConsumerRecords are available.
default void	onException(Exception e) This method is called when an exception occurs during consumer polling or message processing in onConsumerRecords(ConsumerRecords).

Method Detail

onConsumerRecord

default void onConsumerRecord(org.apache.kafka.clients.consumer.ConsumerRecord<K,V> record)

This method is called when a ConsumerRecords is available.

Parameters:

record - the record.

onConsumerRecords

default void onConsumerRecords(org.apache.kafka.clients.consumer.ConsumerRecords<K,V> records)

This method is called when some ConsumerRecords are available.

Parameters:

records - the just-polled consumer records.

onException

default void onException(Exception e)
                  throws Exception

This method is called when an exception occurs during consumer polling or message processing in onConsumerRecords(ConsumerRecords).

Parameters:

e - the exception that occurred.

Throws:

Exception - rethrow an exception to trigger a graceful stop and a retry after the specified delay.