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

Class KafkaDeserializationSchemaWrapper<T>

java.lang.Object

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

Type Parameters:

T - The type created by the deserialization schema.

All Implemented Interfaces:

Serializable, org.apache.flink.api.java.typeutils.ResultTypeQueryable<T>, KafkaDeserializationSchema<T>

@Internal
public class KafkaDeserializationSchemaWrapper<T>
extends Object
implements KafkaDeserializationSchema<T>

A simple wrapper for using the DeserializationSchema with the KafkaDeserializationSchema interface.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor	Description
KafkaDeserializationSchemaWrapper(org.apache.flink.api.common.serialization.DeserializationSchema<T> deserializationSchema)

Method Summary

Modifier and Type	Method	Description
T	deserialize(org.apache.kafka.clients.consumer.ConsumerRecord<byte[],byte[]> record)	Deserializes the Kafka record.
void	deserialize(org.apache.kafka.clients.consumer.ConsumerRecord<byte[],byte[]> message, org.apache.flink.util.Collector<T> out)	Deserializes the Kafka record.
org.apache.flink.api.common.typeinfo.TypeInformation<T>	getProducedType()
boolean	isEndOfStream(T nextElement)	Method to decide whether the element signals the end of the stream.
void	open(org.apache.flink.api.common.serialization.DeserializationSchema.InitializationContext context)	Initialization method for the schema.

Methods inherited from class java.lang.Object

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

Constructor Detail

KafkaDeserializationSchemaWrapper

public KafkaDeserializationSchemaWrapper(org.apache.flink.api.common.serialization.DeserializationSchema<T> deserializationSchema)

Method Detail

open

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

Description copied from interface: KafkaDeserializationSchema

Initialization method for the schema. It is called before the actual working methods KafkaDeserializationSchema.deserialize(org.apache.kafka.clients.consumer.ConsumerRecord<byte[], byte[]>) and thus suitable for one time setup work.

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

Specified by:

open in interface KafkaDeserializationSchema<T>

Parameters:

context - Contextual information that can be used during initialization.

Throws:

Exception

deserialize

public T deserialize(org.apache.kafka.clients.consumer.ConsumerRecord<byte[],byte[]> record)
              throws Exception

Description copied from interface: KafkaDeserializationSchema

Deserializes the Kafka record.

Specified by:

deserialize in interface KafkaDeserializationSchema<T>

Parameters:

record - Kafka record to be deserialized.

Returns:

The deserialized message as an object (null if the message cannot be deserialized).

Throws:

Exception

deserialize

public void deserialize(org.apache.kafka.clients.consumer.ConsumerRecord<byte[],byte[]> message,
                        org.apache.flink.util.Collector<T> out)
                 throws Exception

Description copied from interface: KafkaDeserializationSchema

Deserializes the Kafka record.

Can output multiple records through the Collector. Note that number and size of the produced records should be relatively small. Depending on the source implementation records can be buffered in memory or collecting records might delay emitting checkpoint barrier.

Specified by:

deserialize in interface KafkaDeserializationSchema<T>

Parameters:

message - The message, as a byte array.

out - The collector to put the resulting messages.

Throws:

Exception

isEndOfStream

public boolean isEndOfStream(T nextElement)

Description copied from interface: KafkaDeserializationSchema

Method to decide whether the element signals the end of the stream. If true is returned the element won't be emitted.

Specified by:

isEndOfStream in interface KafkaDeserializationSchema<T>

Parameters:

nextElement - The element to test for the end-of-stream signal.

Returns:

True, if the element signals end of stream, false otherwise.

getProducedType

public org.apache.flink.api.common.typeinfo.TypeInformation<T> getProducedType()

Specified by:

getProducedType in interface org.apache.flink.api.java.typeutils.ResultTypeQueryable<T>