KafkaPartitioner (Flink : Connectors : Kafka 3.3.0-1.19 API)

All Superinterfaces:

Serializable

All Known Implementing Classes:

FlinkFixedPartitioner, FlinkKafkaPartitioner
```
@PublicEvolving
public interface KafkaPartitioner<T>
extends Serializable
```
A KafkaPartitioner wraps logic on how to partition records across partitions of multiple Kafka topics.

Method Summary

All Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method	Description
`default void`	`open(int parallelInstanceId, int parallelInstances)`	Initializer for the partitioner.
`int`	`partition(T record, byte[] key, byte[] value, String targetTopic, int[] partitions)`	Determine the id of the partition that the record should be written to.

- Method Detail
  - open
```
default void open(int parallelInstanceId,
                  int parallelInstances)
```
    Initializer for the partitioner. This is called once on each parallel sink instance of the Flink Kafka producer. This method should be overridden if necessary.
    
    Parameters:
    
    parallelInstanceId - 0-indexed id of the parallel sink instance in Flink
    
    parallelInstances - the total number of parallel instances
  - partition
```
int partition(T record,
              byte[] key,
              byte[] value,
              String targetTopic,
              int[] partitions)
```
    Determine the id of the partition that the record should be written to.
    
    Parameters:
    
    record - the record value
    
    key - serialized key of the record
    
    value - serialized value of the record
    
    targetTopic - target topic for the record
    
    partitions - found partitions for the target topic
    
    Returns:
    
    the id of the target partition