Package org.eso.ias.kafkautils

Class SimpleStringConsumer

java.lang.Object

org.eso.ias.kafkautils.KafkaStringsConsumer

org.eso.ias.kafkautils.SimpleStringConsumer

All Implemented Interfaces:

Runnable, org.apache.kafka.clients.consumer.ConsumerRebalanceListener, KafkaStringsConsumer.StringsConsumer

Direct Known Subclasses:

ReplyKafkaConsumer

public class SimpleStringConsumer
extends KafkaStringsConsumer
implements KafkaStringsConsumer.StringsConsumer

/** Generic Kafka consumer to get strings from a kafka topic.

The strings are passed one at a time to the listener for further processing. This class is inefficient compared to KafkaStringsConsumer that allows to process bounce of events in one single call.

Author:

acaproni

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	SimpleStringConsumer.KafkaConsumerListener	The listener to be notified of strings read from the kafka topic.

Nested classes/interfaces inherited from class org.eso.ias.kafkautils.KafkaStringsConsumer

KafkaStringsConsumer.StreamPosition, KafkaStringsConsumer.StringsConsumer

Field Summary

Fields inherited from class org.eso.ias.kafkautils.KafkaStringsConsumer

DEFAULT_CONSUMER_READY_TIMEOUT, MIN_CONSUMER_READY_TIMEOUT, topicName, WAIT_CONSUMER_READY_TIMEOUT_PROP_NAME

Constructor Summary

Constructors

Constructor	Description
SimpleStringConsumer(String servers, String topicName, String consumerID)	Constructor

Method Summary

Modifier and Type	Method	Description
long	getNumOfProcessedStrings()
void	startGettingStrings(KafkaStringsConsumer.StreamPosition startReadingFrom, SimpleStringConsumer.KafkaConsumerListener listener)	Start polling events from the kafka channel.
void	stringsReceived(Collection<String> strings)	Sends the strings received from the kafka topic to the listener

Methods inherited from class org.eso.ias.kafkautils.KafkaStringsConsumer

getNumOfProcessedRecords, isReady, onPartitionsAssigned, onPartitionsLost, onPartitionsRevoked, run, seekTo, setUp, setUp, startGettingEvents, tearDown, waitUntilConsumerReady

Methods inherited from class java.lang.Object

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

Constructor Details

SimpleStringConsumer

public SimpleStringConsumer(String servers,
 String topicName,
 String consumerID)

Constructor

Parameters:

servers - The kafka servers to connect to

topicName - The name of the topic to get events from

consumerID - the ID of the consumer

Method Details

startGettingStrings

public void startGettingStrings(KafkaStringsConsumer.StreamPosition startReadingFrom,
 SimpleStringConsumer.KafkaConsumerListener listener)
                         throws KafkaUtilsException

Start polling events from the kafka channel.

This method starts the thread that polls the kafka topic and returns after the consumer has been assigned to at least one partition.

Parameters:

startReadingFrom - Starting position in the kafka partition

listener - The listener of events published in the topic

Throws:

KafkaUtilsException - in case of timeout subscribing to the kafkatopic

stringsReceived

public void stringsReceived(Collection<String> strings)

Sends the strings received from the kafka topic to the listener

Specified by:

stringsReceived in interface KafkaStringsConsumer.StringsConsumer

getNumOfProcessedStrings

public long getNumOfProcessedStrings()

Returns:

the number of strings processed