org.apache.kafka.connect.storage

Interface Converter

All Known Implementing Classes:

StringConverter

public interface Converter

The Converter interface provides support for translating between Kafka Connect's runtime data format and byte[]. Internally, this likely includes an intermediate step to the format used by the serialization layer (e.g. JsonNode, GenericRecord, Message).

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.storage.Converter.

Method Summary

Modifier and Type	Method and Description
default org.apache.kafka.common.config.ConfigDef	config() Configuration specification for this converter.
void	configure(Map<String,?> configs, boolean isKey) Configure this class.
default byte[]	fromConnectData(String topic, org.apache.kafka.common.header.Headers headers, Schema schema, Object value) Convert a Kafka Connect data object to a native object for serialization, potentially using the supplied topic and headers in the record as necessary.
byte[]	fromConnectData(String topic, Schema schema, Object value) Convert a Kafka Connect data object to a native object for serialization.
SchemaAndValue	toConnectData(String topic, byte[] value) Convert a native object to a Kafka Connect data object for deserialization.
default SchemaAndValue	toConnectData(String topic, org.apache.kafka.common.header.Headers headers, byte[] value) Convert a native object to a Kafka Connect data object for deserialization, potentially using the supplied topic and headers in the record as necessary.

Method Detail

configure

void configure(Map<String,?> configs,
               boolean isKey)

Configure this class.

Parameters:

configs - configs in key/value pairs

isKey - whether this converter is for a key or a value

fromConnectData

byte[] fromConnectData(String topic,
                       Schema schema,
                       Object value)

Convert a Kafka Connect data object to a native object for serialization.

Parameters:

topic - the topic associated with the data

schema - the schema for the value

value - the value to convert

Returns:

the serialized value

fromConnectData

default byte[] fromConnectData(String topic,
                               org.apache.kafka.common.header.Headers headers,
                               Schema schema,
                               Object value)

Convert a Kafka Connect data object to a native object for serialization, potentially using the supplied topic and headers in the record as necessary.

Connect uses this method directly, and for backward compatibility reasons this method by default will call the fromConnectData(String, Schema, Object) method. Override this method to make use of the supplied headers.

Parameters:

topic - the topic associated with the data

headers - the headers associated with the data; any changes done to the headers are applied to the message sent to the broker

schema - the schema for the value

value - the value to convert

Returns:

the serialized value

toConnectData

SchemaAndValue toConnectData(String topic,
                             byte[] value)

Convert a native object to a Kafka Connect data object for deserialization.

Parameters:

topic - the topic associated with the data

value - the value to convert

Returns:

an object containing the Schema and the converted value

toConnectData

default SchemaAndValue toConnectData(String topic,
                                     org.apache.kafka.common.header.Headers headers,
                                     byte[] value)

Convert a native object to a Kafka Connect data object for deserialization, potentially using the supplied topic and headers in the record as necessary.

Connect uses this method directly, and for backward compatibility reasons this method by default will call the toConnectData(String, byte[]) method. Override this method to make use of the supplied headers.

Parameters:

topic - the topic associated with the data

headers - the headers associated with the data

value - the value to convert

Returns:

an object containing the Schema and the converted value

config

default org.apache.kafka.common.config.ConfigDef config()

Configuration specification for this converter.

Returns:

the configuration specification; may not be null