Package org.apache.kafka.common.serialization

Interface Serializer<T>

Type Parameters:

T - Type to be serialized from.

All Superinterfaces:

AutoCloseable, Closeable

All Known Implementing Classes:

BooleanSerializer, ByteArraySerializer, ByteBufferSerializer, BytesSerializer, DoubleSerializer, FloatSerializer, IntegerSerializer, ListSerializer, LongSerializer, SessionWindowedSerializer, ShortSerializer, StringSerializer, TimeWindowedSerializer, UUIDSerializer, VoidSerializer

public interface Serializer<T>
extends Closeable

An interface for converting objects to bytes. A class that implements this interface is expected to have a constructor with no parameter.

This interface can be combined with ClusterResourceListener to receive cluster metadata once it's available, as well as Monitorable to enable the serializer to register metrics. For the latter, the following tags are automatically added to all metrics registered: config set to either key.serializer or value.serializer, and class set to the serializer class name.

Method Summary

Modifier and Type	Method	Description
default void	close()	Close this serializer.
default void	configure(Map<String,?> configs, boolean isKey)	Configure this class.
default byte[]	serialize(String topic, Headers headers, T data)	Convert data into a byte array.
byte[]	serialize(String topic, T data)	Convert data into a byte array.

Method Details

configure

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

Configure this class.

Parameters:

configs - configs in key/value pairs

isKey - whether the serializer is used for the key or the value

serialize

byte[] serialize(String topic,
 T data)

Convert data into a byte array.

It is recommended to serialize null data to the null byte array.

Parameters:

topic - topic associated with data

data - typed data; may be null

Returns:

serialized bytes; may be null

serialize

default byte[] serialize(String topic,
 Headers headers,
 T data)

Convert data into a byte array.

It is recommended to serialize null data to the null byte array.

Note that the passed in Headers may be empty, but never null. The implementation is allowed to modify the passed in headers, as a side effect of serialization. It is considered best practice to not delete or modify existing headers, but rather only add new ones.

Parameters:

topic - topic associated with data

headers - headers associated with the record

data - typed data; may be null

Returns:

serialized bytes; may be null

close

default void close()

Close this serializer.

This method must be idempotent as it may be called multiple times.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable