TimestampPolicy (kafka 2.61.0 API)

java.lang.Object
- org.apache.beam.sdk.io.kafka.TimestampPolicy<K,V>

Direct Known Subclasses:

CustomTimestampPolicyWithLimitedDelay, TimestampPolicyFactory.LogAppendTimePolicy, TimestampPolicyFactory.ProcessingTimePolicy, TimestampPolicyFactory.TimestampFnPolicy
```
public abstract class TimestampPolicy<K,V>
extends java.lang.Object
```
A timestamp policy to assign event time for messages in a Kafka partition and watermark for it. KafkaIO reader creates one policy using TimestampPolicyFactory for each each of the partitions it reads from. See @TimestampPolicyFactory.LogAppendTimePolicy for example of a policy.

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static class TimestampPolicy.PartitionContext
The context contains state maintained in the reader for the partition.

Constructor Summary

Constructors
Constructor Description

TimestampPolicy()

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`abstract org.joda.time.Instant`	`getTimestampForRecord(TimestampPolicy.PartitionContext ctx, KafkaRecord<K,V> record)`	Returns record timestamp (aka event time).
`abstract org.joda.time.Instant`	`getWatermark(TimestampPolicy.PartitionContext ctx)`	Returns watermark for the partition.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - TimestampPolicy
```
public TimestampPolicy()
```
- Method Detail
  - getTimestampForRecord
```
public abstract org.joda.time.Instant getTimestampForRecord(TimestampPolicy.PartitionContext ctx,
                                                            KafkaRecord<K,V> record)
```
    Returns record timestamp (aka event time). This is often based on the timestamp of the Kafka record. This is invoked for each record when it is processed in the reader.
  - getWatermark
```
public abstract org.joda.time.Instant getWatermark(TimestampPolicy.PartitionContext ctx)
```
    Returns watermark for the partition. It is the timestamp before or at the timestamps of all future records consumed from the partition. See UnboundedSource.UnboundedReader.getWatermark() for more guidance on watermarks. E.g. if the record timestamp is 'LogAppendTime', watermark would be the timestamp of the last record since 'LogAppendTime' monotonically increases within a partition.