org.apache.kafka.clients.consumer

Class ConsumerRecord<K,V>

java.lang.Object

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

public class ConsumerRecord<K,V>
extends Object

A key/value pair to be received from Kafka. This also consists of a topic name and a partition number from which the record is being received, an offset that points to the record in a Kafka partition, and a timestamp as marked by the corresponding ProducerRecord.

Field Summary

Fields

Modifier and Type	Field and Description
static long	NO_TIMESTAMP
static int	NULL_CHECKSUM
static int	NULL_SIZE

Constructor Summary

Constructors

Constructor and Description
ConsumerRecord(String topic, int partition, long offset, K key, V value) Creates a record to be received from a specified topic and partition (provided for compatibility with Kafka 0.9 before the message format supported timestamps and before serialized metadata were exposed).
ConsumerRecord(String topic, int partition, long offset, long timestamp, org.apache.kafka.common.record.TimestampType timestampType, long checksum, int serializedKeySize, int serializedValueSize, K key, V value) Creates a record to be received from a specified topic and partition (provided for compatibility with Kafka 0.10 before the message format supported headers).
ConsumerRecord(String topic, int partition, long offset, long timestamp, org.apache.kafka.common.record.TimestampType timestampType, Long checksum, int serializedKeySize, int serializedValueSize, K key, V value, Headers headers) Creates a record to be received from a specified topic and partition
ConsumerRecord(String topic, int partition, long offset, long timestamp, org.apache.kafka.common.record.TimestampType timestampType, Long checksum, int serializedKeySize, int serializedValueSize, K key, V value, Headers headers, Optional<Integer> leaderEpoch) Creates a record to be received from a specified topic and partition

Method Summary

Modifier and Type	Method and Description
long	checksum() Deprecated. As of Kafka 0.11.0. Because of the potential for message format conversion on the broker, the checksum returned by the broker may not match what was computed by the producer. It is therefore unsafe to depend on this checksum for end-to-end delivery guarantees. Additionally, message format v2 does not include a record-level checksum (for performance, the record checksum was replaced with a batch checksum). To maintain compatibility, a partial checksum computed from the record timestamp, serialized key size, and serialized value size is returned instead, but this should not be depended on for end-to-end reliability.
Headers	headers() The headers (never null)
K	key() The key (or null if no key is specified)
Optional<Integer>	leaderEpoch() Get the leader epoch for the record if available
long	offset() The position of this record in the corresponding Kafka partition.
int	partition() The partition from which this record is received
int	serializedKeySize() The size of the serialized, uncompressed key in bytes.
int	serializedValueSize() The size of the serialized, uncompressed value in bytes.
long	timestamp() The timestamp of this record
org.apache.kafka.common.record.TimestampType	timestampType() The timestamp type of this record
String	topic() The topic this record is received from (never null)
String	toString()
V	value() The value

Methods inherited from class java.lang.Object

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

Field Detail

NO_TIMESTAMP

public static final long NO_TIMESTAMP

See Also:

Constant Field Values

NULL_SIZE

public static final int NULL_SIZE

See Also:

Constant Field Values

NULL_CHECKSUM

public static final int NULL_CHECKSUM

See Also:

Constant Field Values

Constructor Detail

ConsumerRecord

public ConsumerRecord(String topic,
                      int partition,
                      long offset,
                      K key,
                      V value)

Creates a record to be received from a specified topic and partition (provided for compatibility with Kafka 0.9 before the message format supported timestamps and before serialized metadata were exposed).

Parameters:

topic - The topic this record is received from

partition - The partition of the topic this record is received from

offset - The offset of this record in the corresponding Kafka partition

key - The key of the record, if one exists (null is allowed)

value - The record contents

ConsumerRecord

public ConsumerRecord(String topic,
                      int partition,
                      long offset,
                      long timestamp,
                      org.apache.kafka.common.record.TimestampType timestampType,
                      long checksum,
                      int serializedKeySize,
                      int serializedValueSize,
                      K key,
                      V value)

Creates a record to be received from a specified topic and partition (provided for compatibility with Kafka 0.10 before the message format supported headers).

Parameters:

topic - The topic this record is received from

partition - The partition of the topic this record is received from

offset - The offset of this record in the corresponding Kafka partition

timestamp - The timestamp of the record.

timestampType - The timestamp type

checksum - The checksum (CRC32) of the full record

serializedKeySize - The length of the serialized key

serializedValueSize - The length of the serialized value

key - The key of the record, if one exists (null is allowed)

value - The record contents

ConsumerRecord

public ConsumerRecord(String topic,
                      int partition,
                      long offset,
                      long timestamp,
                      org.apache.kafka.common.record.TimestampType timestampType,
                      Long checksum,
                      int serializedKeySize,
                      int serializedValueSize,
                      K key,
                      V value,
                      Headers headers)

Creates a record to be received from a specified topic and partition

Parameters:

topic - The topic this record is received from

partition - The partition of the topic this record is received from

offset - The offset of this record in the corresponding Kafka partition

timestamp - The timestamp of the record.

timestampType - The timestamp type

checksum - The checksum (CRC32) of the full record

serializedKeySize - The length of the serialized key

serializedValueSize - The length of the serialized value

key - The key of the record, if one exists (null is allowed)

value - The record contents

headers - The headers of the record.

ConsumerRecord

public ConsumerRecord(String topic,
                      int partition,
                      long offset,
                      long timestamp,
                      org.apache.kafka.common.record.TimestampType timestampType,
                      Long checksum,
                      int serializedKeySize,
                      int serializedValueSize,
                      K key,
                      V value,
                      Headers headers,
                      Optional<Integer> leaderEpoch)

Creates a record to be received from a specified topic and partition

Parameters:

topic - The topic this record is received from

partition - The partition of the topic this record is received from

offset - The offset of this record in the corresponding Kafka partition

timestamp - The timestamp of the record.

timestampType - The timestamp type

checksum - The checksum (CRC32) of the full record

serializedKeySize - The length of the serialized key

serializedValueSize - The length of the serialized value

key - The key of the record, if one exists (null is allowed)

value - The record contents

headers - The headers of the record

leaderEpoch - Optional leader epoch of the record (may be empty for legacy record formats)

Method Detail

topic

public String topic()

The topic this record is received from (never null)

partition

public int partition()

The partition from which this record is received

headers

public Headers headers()

The headers (never null)

key

public K key()

The key (or null if no key is specified)

value

public V value()

The value

offset

public long offset()

The position of this record in the corresponding Kafka partition.

timestamp

public long timestamp()

The timestamp of this record

timestampType

public org.apache.kafka.common.record.TimestampType timestampType()

The timestamp type of this record

checksum

@Deprecated
public long checksum()

Deprecated. As of Kafka 0.11.0. Because of the potential for message format conversion on the broker, the checksum returned by the broker may not match what was computed by the producer. It is therefore unsafe to depend on this checksum for end-to-end delivery guarantees. Additionally, message format v2 does not include a record-level checksum (for performance, the record checksum was replaced with a batch checksum). To maintain compatibility, a partial checksum computed from the record timestamp, serialized key size, and serialized value size is returned instead, but this should not be depended on for end-to-end reliability.

The checksum (CRC32) of the record.

serializedKeySize

public int serializedKeySize()

The size of the serialized, uncompressed key in bytes. If key is null, the returned size is -1.

serializedValueSize

public int serializedValueSize()

The size of the serialized, uncompressed value in bytes. If value is null, the returned size is -1.

leaderEpoch

public Optional<Integer> leaderEpoch()

Get the leader epoch for the record if available

Returns:

the leader epoch or empty for legacy record formats

toString

public String toString()

Overrides:

toString in class Object