org.apache.kafka.streams.processor

Interface Processor<K,V>

Type Parameters:

K - the type of keys

V - the type of values

All Known Implementing Classes:

AbstractProcessor

@InterfaceStability.Evolving
public interface Processor<K,V>

A processor of key-value pair records.

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Close this processor and clean up any resources.
void	init(ProcessorContext context) Initialize this processor with the given context.
void	process(K key, V value) Process the record with the given key and value.
void	punctuate(long timestamp) Perform any periodic operations, if this processor schedule itself with the context during initialization.

Method Detail

init

void init(ProcessorContext context)

Initialize this processor with the given context. The framework ensures this is called once per processor when the topology that contains it is initialized.

If this processor is to be called periodically by the framework, then this method should schedule itself with the provided context.

Parameters:

context - the context; may not be null

process

void process(K key,
           V value)

Process the record with the given key and value.

Parameters:

key - the key for the record

value - the value for the record

punctuate

void punctuate(long timestamp)

Perform any periodic operations, if this processor schedule itself with the context during initialization.

Parameters:

timestamp - the stream time when this method is being called

close

void close()

Close this processor and clean up any resources. Be aware that close() is called after an internal cleanup. Thus, it is not possible to write anything to Kafka as underlying clients are already closed.

Note: Do not close any streams managed resources, like StateStores here, as they are managed by the library.