org.apache.kafka.connect.transforms

Interface Transformation<R extends ConnectRecord<R>>

Type Parameters:

R - The type of record (must be an implementation of ConnectRecord)

All Superinterfaces:

AutoCloseable, Closeable, Configurable

public interface Transformation<R extends ConnectRecord<R>>
extends Configurable, Closeable

Single message transformation for Kafka Connect record types.

Connectors can be configured with transformations to make lightweight message-at-a-time modifications.

Kafka Connect may discover implementations of this interface using the Java ServiceLoader mechanism. To support this, implementations of this interface should also contain a service provider configuration file in META-INF/services/org.apache.kafka.connect.transforms.Transformation.

Method Summary

Modifier and Type	Method and Description
R	apply(R record) Apply transformation to the record and return another record object (which may be record itself) or null, corresponding to a map or filter operation respectively.
void	close() Signal that this transformation instance will no longer will be used.
ConfigDef	config() Configuration specification for this transformation.

Methods inherited from interface org.apache.kafka.common.Configurable

configure

Method Detail

apply

R apply(R record)

Apply transformation to the record and return another record object (which may be record itself) or null, corresponding to a map or filter operation respectively.

A transformation must not mutate objects reachable from the given record (including, but not limited to, Headers, Structs, Lists, and Maps). If such objects need to be changed, a new ConnectRecord should be created and returned.

The implementation must be thread-safe.

Parameters:

record - the record to be transformed; may not be null

Returns:

the transformed record; may be null to indicate that the record should be dropped

config

ConfigDef config()

Configuration specification for this transformation.

close

void close()

Signal that this transformation instance will no longer will be used.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable