Package org.apache.flink.streaming.connectors.kafka.internals

Class KafkaSerializationSchemaWrapper<T>

java.lang.Object

org.apache.flink.streaming.connectors.kafka.internals.KafkaSerializationSchemaWrapper<T>

All Implemented Interfaces:

Serializable, KafkaContextAware<T>, KafkaSerializationSchema<T>

@Internal
public class KafkaSerializationSchemaWrapper<T>
extends Object
implements KafkaSerializationSchema<T>, KafkaContextAware<T>

An adapter from old style interfaces such as SerializationSchema, FlinkKafkaPartitioner to the KafkaSerializationSchema.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor	Description
KafkaSerializationSchemaWrapper(String topic, FlinkKafkaPartitioner<T> partitioner, boolean writeTimestamp, org.apache.flink.api.common.serialization.SerializationSchema<T> serializationSchema)

Method Summary

Modifier and Type	Method	Description
String	getTargetTopic(T element)	Returns the topic that the presented element should be sent to.
void	open(org.apache.flink.api.common.serialization.SerializationSchema.InitializationContext context)	Initialization method for the schema.
org.apache.kafka.clients.producer.ProducerRecord<byte[],byte[]>	serialize(T element, Long timestamp)	Serializes given element and returns it as a ProducerRecord.
void	setNumParallelInstances(int numParallelInstances)	Sets the parallelism with which the parallel task of the Kafka Producer runs.
void	setParallelInstanceId(int parallelInstanceId)	Sets the number of the parallel subtask that the Kafka Producer is running on.
void	setPartitions(int[] partitions)	Sets the available partitions for the topic returned from KafkaContextAware.getTargetTopic(Object).
void	setWriteTimestamp(boolean writeTimestamp)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

KafkaSerializationSchemaWrapper

public KafkaSerializationSchemaWrapper(String topic,
                                       FlinkKafkaPartitioner<T> partitioner,
                                       boolean writeTimestamp,
                                       org.apache.flink.api.common.serialization.SerializationSchema<T> serializationSchema)

Method Detail

open

public void open(org.apache.flink.api.common.serialization.SerializationSchema.InitializationContext context)
          throws Exception

Description copied from interface: KafkaSerializationSchema

Initialization method for the schema. It is called before the actual working methods KafkaSerializationSchema.serialize(Object, Long) and thus suitable for one time setup work.

The provided SerializationSchema.InitializationContext can be used to access additional features such as e.g. registering user metrics.

Specified by:

open in interface KafkaSerializationSchema<T>

Parameters:

context - Contextual information that can be used during initialization.

Throws:

Exception

serialize

public org.apache.kafka.clients.producer.ProducerRecord<byte[],byte[]> serialize(T element,
                                                                                       @Nullable
                                                                                       Long timestamp)

Description copied from interface: KafkaSerializationSchema

Serializes given element and returns it as a ProducerRecord.

Specified by:

serialize in interface KafkaSerializationSchema<T>

Parameters:

element - element to be serialized

timestamp - timestamp (can be null)

Returns:

Kafka ProducerRecord

getTargetTopic

public String getTargetTopic(T element)

Description copied from interface: KafkaContextAware

Returns the topic that the presented element should be sent to. This is not used for setting the topic (this is done via the ProducerRecord that is returned from KafkaSerializationSchema.serialize(Object, Long), it is only used for getting the available partitions that are presented to KafkaContextAware.setPartitions(int[]).

Specified by:

getTargetTopic in interface KafkaContextAware<T>

setPartitions

public void setPartitions(int[] partitions)

Description copied from interface: KafkaContextAware

Sets the available partitions for the topic returned from KafkaContextAware.getTargetTopic(Object).

Specified by:

setPartitions in interface KafkaContextAware<T>

setParallelInstanceId

public void setParallelInstanceId(int parallelInstanceId)

Description copied from interface: KafkaContextAware

Sets the number of the parallel subtask that the Kafka Producer is running on. The numbering starts from 0 and goes up to parallelism-1 (parallelism as returned by KafkaContextAware.setNumParallelInstances(int)).

Specified by:

setParallelInstanceId in interface KafkaContextAware<T>

setNumParallelInstances

public void setNumParallelInstances(int numParallelInstances)

Description copied from interface: KafkaContextAware

Sets the parallelism with which the parallel task of the Kafka Producer runs.

Specified by:

setNumParallelInstances in interface KafkaContextAware<T>

setWriteTimestamp

public void setWriteTimestamp(boolean writeTimestamp)