Package org.apache.flink.connector.kafka.source.reader.deserializer

Interface KafkaRecordDeserializationSchema<T>

All Superinterfaces:
org.apache.flink.api.java.typeutils.ResultTypeQueryable<T>, Serializable
@PublicEvolving public interface KafkaRecordDeserializationSchema<T> extends Serializable, org.apache.flink.api.java.typeutils.ResultTypeQueryable<T>
An interface for the deserialization of Kafka records.

  • Method Details

    • open

      default void open(org.apache.flink.api.common.serialization.DeserializationSchema.InitializationContext context) throws Exception
      Initialization method for the schema. It is called before the actual working methods deserialize(org.apache.kafka.clients.consumer.ConsumerRecord<byte[], byte[]>, org.apache.flink.util.Collector<T>) 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

    • deserialize

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

      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:
      record - The ConsumerRecord to deserialize.
      out - The collector to put the resulting messages.
      Throws:
      IOException

    • of

      @Deprecated static <V> KafkaRecordDeserializationSchema<V> of(KafkaDeserializationSchema<V> kafkaDeserializationSchema)
      Deprecated.
      Will be removed with KafkaDeserializationSchema.
      Wraps a legacy KafkaDeserializationSchema as the deserializer of the ConsumerRecords.

      Note that the KafkaDeserializationSchema.isEndOfStream(Object) method will no longer be used to determine the end of the stream.

      Type Parameters:
      V - the return type of the deserialized record.
      Parameters:
      kafkaDeserializationSchema - the legacy KafkaDeserializationSchema to use.
      Returns:
      A KafkaRecordDeserializationSchema that uses the given KafkaDeserializationSchema to deserialize the ConsumerRecords.

    • valueOnly

      static <V> KafkaRecordDeserializationSchema<V> valueOnly(org.apache.flink.api.common.serialization.DeserializationSchema<V> valueDeserializationSchema)
      Wraps a DeserializationSchema as the value deserialization schema of the ConsumerRecords. The other fields such as key, headers, timestamp are ignored.

      Note that the DeserializationSchema.isEndOfStream(Object) method will no longer be used to determine the end of the stream.

      Type Parameters:
      V - the type of the deserialized record.
      Parameters:
      valueDeserializationSchema - the DeserializationSchema used to deserialized the value of a ConsumerRecord.
      Returns:
      A KafkaRecordDeserializationSchema that uses the given DeserializationSchema to deserialize a ConsumerRecord from its value.

    • valueOnly

      static <V> KafkaRecordDeserializationSchema<V> valueOnly(Class<? extends org.apache.kafka.common.serialization.Deserializer<V>> valueDeserializerClass)
      Wraps a Kafka Deserializer to a KafkaRecordDeserializationSchema.
      Type Parameters:
      V - the value type.
      Parameters:
      valueDeserializerClass - the deserializer class used to deserialize the value.
      Returns:
      A KafkaRecordDeserializationSchema that deserialize the value with the given deserializer.

    • valueOnly

      static <V, D extends org.apache.kafka.common.serialization.Deserializer<V>> KafkaRecordDeserializationSchema<V> valueOnly(Class<D> valueDeserializerClass, Map<String,String> config)
      Wraps a Kafka Deserializer to a KafkaRecordDeserializationSchema.
      Type Parameters:
      V - the value type.
      D - the type of the deserializer.
      Parameters:
      valueDeserializerClass - the deserializer class used to deserialize the value.
      config - the configuration of the value deserializer. If the deserializer is an implementation of Configurable, the configuring logic will be handled by Configurable.configure(Map) with the given
      invalid reference 
      config
      , otherwise Deserializer.configure(Map, boolean) will be invoked.
      Returns:
      A KafkaRecordDeserializationSchema that deserialize the value with the given deserializer.