Package org.apache.kafka.connect.storage

Interface Converter

All Superinterfaces:
AutoCloseable, Closeable
All Known Implementing Classes:
StringConverter
public interface Converter extends Closeable
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.

Implement Monitorable to enable the converter to register metrics. The following tags are automatically added to all metrics registered: connector set to connector name, task set to the task id and converter set to either key or value.

  • Method Summary

    Modifier and Type
    Method
    Description
    default void
    close()
     
    default ConfigDef
    config()
    Configuration specification for this converter.
    void
    configure(Map<String,?> configs, boolean isKey)
    Configure this class.
    default byte[]
    fromConnectData(String topic, 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, 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 Details

    • 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, 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, 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 ConfigDef config()
      Configuration specification for this converter.
      Returns:
      the configuration specification; may not be null

    • close

      default void close() throws IOException
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Throws:
      IOException