Class MockConsumer<K,V>

java.lang.Object

org.apache.kafka.clients.consumer.MockConsumer<K,V>

All Implemented Interfaces:

Closeable, AutoCloseable, Consumer<K,V>

@Public
public class MockConsumer<K,V>
extends Object
implements Consumer<K,V>

A mock of the Consumer interface you can use for testing code that uses Kafka. This class is not threadsafe . However, you can use the schedulePollTask(Runnable) method to write multithreaded tests where a driver thread waits for poll(Duration) to be called by a background thread and then can safely perform operations during a callback.

Constructor Summary

Constructors

Constructor	Description
MockConsumer(String offsetResetStrategy)	A mock consumer is instantiated by providing ConsumerConfig.AUTO_OFFSET_RESET_CONFIG value as the input.
MockConsumer(OffsetResetStrategy offsetResetStrategy)	Deprecated. Since 4.0.

Method Summary

Modifier and Type	Method	Description
List<KafkaMetric>	addedMetrics()	Returns the metrics registered via registerMetricForSubscription(KafkaMetric).
void	addRecord(ConsumerRecord<K,V> record)	Adds a record to be returned when poll(Duration) is called.
void	assign(Collection<TopicPartition> partitions)
Set<TopicPartition>	assignment()
Map<TopicPartition, Long>	beginningOffsets(Collection<TopicPartition> partitions)
Map<TopicPartition, Long>	beginningOffsets(Collection<TopicPartition> partitions, Duration timeout)
Uuid	clientInstanceId(Duration timeout)	See KafkaConsumer.clientInstanceId(Duration)
void	close()
void	close(Duration timeout)	Deprecated.
void	close(CloseOptions option)
boolean	closed()	Returns whether this consumer has been closed.
void	commitAsync()
void	commitAsync(Map<TopicPartition, OffsetAndMetadata> offsets, OffsetCommitCallback callback)
void	commitAsync(OffsetCommitCallback callback)
void	commitSync()
void	commitSync(Duration timeout)
void	commitSync(Map<TopicPartition, OffsetAndMetadata> offsets)
void	commitSync(Map<TopicPartition, OffsetAndMetadata> offsets, Duration timeout)
Map<TopicPartition, OffsetAndMetadata>	committed(Set<TopicPartition> partitions)
Map<TopicPartition, OffsetAndMetadata>	committed(Set<TopicPartition> partitions, Duration timeout)
OptionalLong	currentLag(TopicPartition topicPartition)
void	disableTelemetry()	Disables telemetry for this mock consumer.
Map<TopicPartition, Long>	endOffsets(Collection<TopicPartition> partitions)
Map<TopicPartition, Long>	endOffsets(Collection<TopicPartition> partitions, Duration timeout)
void	enforceRebalance()
void	enforceRebalance(String reason)
ConsumerGroupMetadata	groupMetadata()
void	injectTimeoutException(int injectTimeoutExceptionCounter)
Duration	lastPollTimeout()	Returns the timeout used in the last poll(Duration) call.
Map<String, List<PartitionInfo>>	listTopics()
Map<String, List<PartitionInfo>>	listTopics(Duration timeout)
void	losePartitions(Collection<TopicPartition> partitionsLost)	Simulates a partition loss event.
Map<MetricName, ? extends Metric>	metrics()
Map<TopicPartition, OffsetAndTimestamp>	offsetsForTimes(Map<TopicPartition, Long> timestampsToSearch)
Map<TopicPartition, OffsetAndTimestamp>	offsetsForTimes(Map<TopicPartition, Long> timestampsToSearch, Duration timeout)
List<PartitionInfo>	partitionsFor(String topic)
List<PartitionInfo>	partitionsFor(String topic, Duration timeout)
void	pause(Collection<TopicPartition> partitions)
Set<TopicPartition>	paused()
ConsumerRecords<K,V>	poll(Duration timeout)
long	position(TopicPartition partition)
long	position(TopicPartition partition, Duration timeout)
void	rebalance(Collection<TopicPartition> newAssignment)	Simulate a rebalance event.
void	registerMetricForSubscription(KafkaMetric metric)
void	resetShouldRebalance()	Resets the rebalance flag set by enforceRebalance().
void	resume(Collection<TopicPartition> partitions)
void	scheduleNopPollTask()	Schedules a no-op task to be executed during a poll invocation.
void	schedulePollTask(Runnable task)	Schedule a task to be executed during a poll().
void	seek(TopicPartition partition, long offset)
void	seek(TopicPartition partition, OffsetAndMetadata offsetAndMetadata)
void	seekToBeginning(Collection<TopicPartition> partitions)
void	seekToEnd(Collection<TopicPartition> partitions)
void	setClientInstanceId(Uuid instanceId)	Sets the client instance ID for this mock consumer.
void	setMaxPollRecords(long maxPollRecords)	Sets the maximum number of records returned in a single call to poll(Duration).
void	setOffsetsException(KafkaException exception)	Sets an exception to throw when offset-related methods are called.
void	setPollException(KafkaException exception)	Sets an exception to throw when poll(Duration) is called.
boolean	shouldRebalance()	Returns whether a rebalance has been triggered via enforceRebalance().
void	subscribe(Collection<String> topics)
void	subscribe(Collection<String> topics, ConsumerRebalanceListener listener)
void	subscribe(Pattern pattern)
void	subscribe(Pattern pattern, ConsumerRebalanceListener listener)
void	subscribe(SubscriptionPattern pattern)
void	subscribe(SubscriptionPattern pattern, ConsumerRebalanceListener listener)
Set<String>	subscription()
void	unregisterMetricFromSubscription(KafkaMetric metric)
void	unsubscribe()
void	updateBeginningOffsets(Map<TopicPartition, Long> newOffsets)	Updates the beginning offsets for the specified partitions.
void	updateDurationOffsets(Map<TopicPartition, Long> newOffsets)	Updates the duration-based reset offsets for the specified partitions.
void	updateEndOffsets(Map<TopicPartition, Long> newOffsets)	Updates the end offsets for the specified partitions.
void	updatePartitions(String topic, List<PartitionInfo> partitions)	Updates the partition information for the specified topic.
void	wakeup()

Methods inherited from class Object

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

Constructor Details

MockConsumer

@Deprecated
public MockConsumer(OffsetResetStrategy offsetResetStrategy)

Deprecated.

Since 4.0. Use MockConsumer(String) instead.

MockConsumer

public MockConsumer(String offsetResetStrategy)

A mock consumer is instantiated by providing ConsumerConfig.AUTO_OFFSET_RESET_CONFIG value as the input.

Parameters:

offsetResetStrategy - the offset reset strategy to use

Method Details

assignment

public Set<TopicPartition> assignment()

Specified by:

assignment in interface Consumer<K,V>

See Also:

• KafkaConsumer.assignment()

rebalance

public void rebalance(Collection<TopicPartition> newAssignment)

Simulate a rebalance event.

losePartitions

public void losePartitions(Collection<TopicPartition> partitionsLost)

Simulates a partition loss event. Calls ConsumerRebalanceListener.onPartitionsLost(Collection) for the specified partitions and removes them from the current assignment. Unlike rebalance(Collection), which calls ConsumerRebalanceListener.onPartitionsRevoked(Collection), this method models the case where the consumer loses partitions without a graceful revoke..

Only records belonging to the lost partitions are cleared; records for retained partitions are unaffected.

Parameters:

partitionsLost - the partitions to lose; all must be currently assigned

Throws:

IllegalStateException - if any partition is not currently assigned

subscription

public Set<String> subscription()

Specified by:

subscription in interface Consumer<K,V>

See Also:

• KafkaConsumer.subscription()

subscribe

public void subscribe(Collection<String> topics)

Specified by:

subscribe in interface Consumer<K,V>

See Also:

• KafkaConsumer.subscribe(Collection)

subscribe

public void subscribe(Pattern pattern,
 ConsumerRebalanceListener listener)

Specified by:

subscribe in interface Consumer<K,V>

See Also:

• KafkaConsumer.subscribe(Pattern, ConsumerRebalanceListener)

subscribe

public void subscribe(Pattern pattern)

Specified by:

subscribe in interface Consumer<K,V>

See Also:

• KafkaConsumer.subscribe(Pattern)

subscribe

public void subscribe(SubscriptionPattern pattern,
 ConsumerRebalanceListener listener)

Specified by:

subscribe in interface Consumer<K,V>

See Also:

• KafkaConsumer.subscribe(SubscriptionPattern, ConsumerRebalanceListener)

subscribe

public void subscribe(SubscriptionPattern pattern)

Specified by:

subscribe in interface Consumer<K,V>

See Also:

• KafkaConsumer.subscribe(SubscriptionPattern)

subscribe

public void subscribe(Collection<String> topics,
 ConsumerRebalanceListener listener)

Specified by:

subscribe in interface Consumer<K,V>

See Also:

• KafkaConsumer.subscribe(Collection, ConsumerRebalanceListener)

registerMetricForSubscription

public void registerMetricForSubscription(KafkaMetric metric)

Specified by:

registerMetricForSubscription in interface Consumer<K,V>

See Also:

• KafkaConsumer.registerMetricForSubscription(KafkaMetric)

unregisterMetricFromSubscription

public void unregisterMetricFromSubscription(KafkaMetric metric)

Specified by:

unregisterMetricFromSubscription in interface Consumer<K,V>

See Also:

• KafkaConsumer.unregisterMetricFromSubscription(KafkaMetric)

assign

public void assign(Collection<TopicPartition> partitions)

Specified by:

assign in interface Consumer<K,V>

See Also:

• KafkaConsumer.assign(Collection)

unsubscribe

public void unsubscribe()

Specified by:

unsubscribe in interface Consumer<K,V>

See Also:

• KafkaConsumer.unsubscribe()

poll

public ConsumerRecords<K,V> poll(Duration timeout)

Specified by:

poll in interface Consumer<K,V>

See Also:

• KafkaConsumer.poll(Duration)

addRecord

public void addRecord(ConsumerRecord<K,V> record)

Adds a record to be returned when poll(Duration) is called.

Parameters:

record - the record to add

Throws:

IllegalStateException - if the partition is not assigned to the consumer

setMaxPollRecords

public void setMaxPollRecords(long maxPollRecords)

Sets the maximum number of records returned in a single call to poll(Duration).

Parameters:

maxPollRecords - the max.poll.records.

setPollException

public void setPollException(KafkaException exception)

Sets an exception to throw when poll(Duration) is called.

Parameters:

exception - the exception to throw

setOffsetsException

public void setOffsetsException(KafkaException exception)

Sets an exception to throw when offset-related methods are called.

Parameters:

exception - the exception to throw

commitAsync

public void commitAsync(Map<TopicPartition, OffsetAndMetadata> offsets,
 OffsetCommitCallback callback)

Specified by:

commitAsync in interface Consumer<K,V>

See Also:

• KafkaConsumer.commitAsync(Map, OffsetCommitCallback)

commitSync

public void commitSync(Map<TopicPartition, OffsetAndMetadata> offsets)

Specified by:

commitSync in interface Consumer<K,V>

See Also:

• KafkaConsumer.commitSync(Map)

commitAsync

public void commitAsync()

Specified by:

commitAsync in interface Consumer<K,V>

See Also:

• KafkaConsumer.commitAsync()

commitAsync

public void commitAsync(OffsetCommitCallback callback)

Specified by:

commitAsync in interface Consumer<K,V>

See Also:

• KafkaConsumer.commitAsync(OffsetCommitCallback)

commitSync

public void commitSync()

Specified by:

commitSync in interface Consumer<K,V>

See Also:

• KafkaConsumer.commitSync()

commitSync

public void commitSync(Duration timeout)

Specified by:

commitSync in interface Consumer<K,V>

See Also:

• KafkaConsumer.commitSync(Duration)

commitSync

public void commitSync(Map<TopicPartition, OffsetAndMetadata> offsets,
 Duration timeout)

Specified by:

commitSync in interface Consumer<K,V>

See Also:

• KafkaConsumer.commitSync(Map, Duration)

seek

public void seek(TopicPartition partition,
 long offset)

Specified by:

seek in interface Consumer<K,V>

See Also:

• KafkaConsumer.seek(TopicPartition, long)

seek

public void seek(TopicPartition partition,
 OffsetAndMetadata offsetAndMetadata)

Specified by:

seek in interface Consumer<K,V>

See Also:

• KafkaConsumer.seek(TopicPartition, OffsetAndMetadata)

committed

public Map<TopicPartition, OffsetAndMetadata> committed(Set<TopicPartition> partitions)

Specified by:

committed in interface Consumer<K,V>

See Also:

• KafkaConsumer.committed(Set)

committed

public Map<TopicPartition, OffsetAndMetadata> committed(Set<TopicPartition> partitions,
 Duration timeout)

Specified by:

committed in interface Consumer<K,V>

See Also:

• KafkaConsumer.committed(Set, Duration)

position

public long position(TopicPartition partition)

Specified by:

position in interface Consumer<K,V>

See Also:

• KafkaConsumer.position(TopicPartition)

position

public long position(TopicPartition partition,
 Duration timeout)

Specified by:

position in interface Consumer<K,V>

See Also:

• KafkaConsumer.position(TopicPartition, Duration)

seekToBeginning

public void seekToBeginning(Collection<TopicPartition> partitions)

Specified by:

seekToBeginning in interface Consumer<K,V>

See Also:

• KafkaConsumer.seekToBeginning(Collection)

updateBeginningOffsets

public void updateBeginningOffsets(Map<TopicPartition, Long> newOffsets)

Updates the beginning offsets for the specified partitions.

Parameters:

newOffsets - the beginning offsets to set

seekToEnd

public void seekToEnd(Collection<TopicPartition> partitions)

Specified by:

seekToEnd in interface Consumer<K,V>

See Also:

• KafkaConsumer.seekToEnd(Collection)

updateEndOffsets

public void updateEndOffsets(Map<TopicPartition, Long> newOffsets)

Updates the end offsets for the specified partitions.

Parameters:

newOffsets - the end offsets to set

updateDurationOffsets

public void updateDurationOffsets(Map<TopicPartition, Long> newOffsets)

Updates the duration-based reset offsets for the specified partitions.

Parameters:

newOffsets - the duration offsets to set

disableTelemetry

public void disableTelemetry()

Disables telemetry for this mock consumer.

injectTimeoutException

public void injectTimeoutException(int injectTimeoutExceptionCounter)

Parameters:

injectTimeoutExceptionCounter - use -1 for infinite

setClientInstanceId

public void setClientInstanceId(Uuid instanceId)

Sets the client instance ID for this mock consumer.

Parameters:

instanceId - the client instance ID

clientInstanceId

public Uuid clientInstanceId(Duration timeout)

Description copied from interface: Consumer

See KafkaConsumer.clientInstanceId(Duration)

Specified by:

clientInstanceId in interface Consumer<K,V>

metrics

public Map<MetricName, ? extends Metric> metrics()

Specified by:

metrics in interface Consumer<K,V>

See Also:

• KafkaConsumer.metrics()

partitionsFor

public List<PartitionInfo> partitionsFor(String topic)

Specified by:

partitionsFor in interface Consumer<K,V>

See Also:

• KafkaConsumer.partitionsFor(String)

listTopics

public Map<String, List<PartitionInfo>> listTopics()

Specified by:

listTopics in interface Consumer<K,V>

See Also:

• KafkaConsumer.listTopics()

updatePartitions

public void updatePartitions(String topic,
 List<PartitionInfo> partitions)

Updates the partition information for the specified topic.

Parameters:

topic - the topic to update

partitions - the partition information

pause

public void pause(Collection<TopicPartition> partitions)

Specified by:

pause in interface Consumer<K,V>

See Also:

• KafkaConsumer.pause(Collection)

resume

public void resume(Collection<TopicPartition> partitions)

Specified by:

resume in interface Consumer<K,V>

See Also:

• KafkaConsumer.resume(Collection)

offsetsForTimes

public Map<TopicPartition, OffsetAndTimestamp> offsetsForTimes(Map<TopicPartition, Long> timestampsToSearch)

Specified by:

offsetsForTimes in interface Consumer<K,V>

See Also:

• KafkaConsumer.offsetsForTimes(Map)

beginningOffsets

public Map<TopicPartition, Long> beginningOffsets(Collection<TopicPartition> partitions)

Specified by:

beginningOffsets in interface Consumer<K,V>

See Also:

• KafkaConsumer.beginningOffsets(Collection)

endOffsets

public Map<TopicPartition, Long> endOffsets(Collection<TopicPartition> partitions)

Specified by:

endOffsets in interface Consumer<K,V>

See Also:

• KafkaConsumer.endOffsets(Collection)

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in interface Consumer<K,V>

See Also:

• KafkaConsumer.close()

close

@Deprecated
public void close(Duration timeout)

Deprecated.

Specified by:

close in interface Consumer<K,V>

See Also:

• KafkaConsumer.close(Duration)

closed

public boolean closed()

Returns whether this consumer has been closed.

Returns:

true if closed, false otherwise

wakeup

public void wakeup()

Specified by:

wakeup in interface Consumer<K,V>

See Also:

• KafkaConsumer.wakeup()

close

public void close(CloseOptions option)

Specified by:

close in interface Consumer<K,V>

See Also:

• KafkaConsumer.close(CloseOptions)

schedulePollTask

public void schedulePollTask(Runnable task)

Schedule a task to be executed during a poll(). One enqueued task will be executed per poll(Duration) invocation. You can use this repeatedly to mock out multiple responses to poll invocations.

Parameters:

task - the task to be executed

scheduleNopPollTask

public void scheduleNopPollTask()

Schedules a no-op task to be executed during a poll invocation.

paused

public Set<TopicPartition> paused()

Specified by:

paused in interface Consumer<K,V>

See Also:

• KafkaConsumer.paused()

partitionsFor

public List<PartitionInfo> partitionsFor(String topic,
 Duration timeout)

Specified by:

partitionsFor in interface Consumer<K,V>

See Also:

• KafkaConsumer.partitionsFor(String, Duration)

listTopics

public Map<String, List<PartitionInfo>> listTopics(Duration timeout)

Specified by:

listTopics in interface Consumer<K,V>

See Also:

• KafkaConsumer.listTopics(Duration)

offsetsForTimes

public Map<TopicPartition, OffsetAndTimestamp> offsetsForTimes(Map<TopicPartition, Long> timestampsToSearch,
 Duration timeout)

Specified by:

offsetsForTimes in interface Consumer<K,V>

See Also:

• KafkaConsumer.offsetsForTimes(Map, Duration)

beginningOffsets

public Map<TopicPartition, Long> beginningOffsets(Collection<TopicPartition> partitions,
 Duration timeout)

Specified by:

beginningOffsets in interface Consumer<K,V>

See Also:

• KafkaConsumer.beginningOffsets(Collection, Duration)

endOffsets

public Map<TopicPartition, Long> endOffsets(Collection<TopicPartition> partitions,
 Duration timeout)

Specified by:

endOffsets in interface Consumer<K,V>

See Also:

• KafkaConsumer.endOffsets(Collection, Duration)

currentLag

public OptionalLong currentLag(TopicPartition topicPartition)

Specified by:

currentLag in interface Consumer<K,V>

See Also:

• KafkaConsumer.currentLag(TopicPartition)

groupMetadata

public ConsumerGroupMetadata groupMetadata()

Specified by:

groupMetadata in interface Consumer<K,V>

See Also:

• KafkaConsumer.groupMetadata()

enforceRebalance

public void enforceRebalance()

Specified by:

enforceRebalance in interface Consumer<K,V>

See Also:

• KafkaConsumer.enforceRebalance()

enforceRebalance

public void enforceRebalance(String reason)

Specified by:

enforceRebalance in interface Consumer<K,V>

See Also:

• KafkaConsumer.enforceRebalance(String)

shouldRebalance

public boolean shouldRebalance()

Returns whether a rebalance has been triggered via enforceRebalance().

Returns:

true if rebalance is pending, false otherwise

resetShouldRebalance

public void resetShouldRebalance()

Resets the rebalance flag set by enforceRebalance().

lastPollTimeout

public Duration lastPollTimeout()

Returns the timeout used in the last poll(Duration) call.

Returns:

the last poll timeout, or null if poll has not been called

addedMetrics

public List<KafkaMetric> addedMetrics()

Returns the metrics registered via registerMetricForSubscription(KafkaMetric).

Returns:

an unmodifiable list of added metrics