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

Interface KafkaDeserializationSchema<T>

Type Parameters:
T - The type created by the keyed deserialization schema.
All Superinterfaces:
org.apache.flink.api.java.typeutils.ResultTypeQueryable<T>, Serializable
All Known Subinterfaces:
KeyedDeserializationSchema<T>
All Known Implementing Classes:
JSONKeyValueDeserializationSchema, KafkaDeserializationSchemaWrapper, TypeInformationKeyValueSerializationSchema
@PublicEvolving @Deprecated public interface KafkaDeserializationSchema<T> extends Serializable, org.apache.flink.api.java.typeutils.ResultTypeQueryable<T>
Deprecated.
Will be turned into internal API when FlinkKafkaConsumer is removed.
The deserialization schema describes how to turn the Kafka ConsumerRecords into data types (Java/Scala objects) that are processed by Flink.

  • Method Summary

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

    Methods inherited from interface org.apache.flink.api.java.typeutils.ResultTypeQueryable

    getProducedType

  • Method Details

    • open

      default void open(org.apache.flink.api.common.serialization.DeserializationSchema.InitializationContext context) throws Exception
      Deprecated.
      Initialization method for the schema. It is called before the actual working methods 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.

      Parameters:
      context - Contextual information that can be used during initialization.
      Throws:
      Exception

    • isEndOfStream

      boolean isEndOfStream(T nextElement)
      Deprecated.
      Method to decide whether the element signals the end of the stream. If true is returned the element won't be emitted.
      Parameters:
      nextElement - The element to test for the end-of-stream signal.
      Returns:
      True, if the element signals end of stream, false otherwise.

    • deserialize

      T deserialize(org.apache.kafka.clients.consumer.ConsumerRecord<byte[],byte[]> record) throws Exception
      Deprecated.
      Deserializes the Kafka record.
      Parameters:
      record - Kafka record to be deserialized.
      Returns:
      The deserialized message as an object (null if the message cannot be deserialized).
      Throws:
      Exception

    • deserialize

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

      Parameters:
      message - The message, as a byte array.
      out - The collector to put the resulting messages.
      Throws:
      Exception