Package org.apache.avro.message

Class BinaryMessageDecoder<D>

java.lang.Object
org.apache.avro.message.MessageDecoder.BaseDecoder<D>
org.apache.avro.message.BinaryMessageDecoder<D>
All Implemented Interfaces:
MessageDecoder<D>
public class BinaryMessageDecoder<D> extends MessageDecoder.BaseDecoder<D>
A MessageDecoder that reads a binary-encoded datum. This checks for the datum header and decodes the payload with the schema that corresponds to the 8-byte schema fingerprint.

Instances can decode message payloads for known schemas, which are schemas added using addSchema(Schema), schemas resolved by the SchemaStore passed to the constructor, or the expected schema passed to the constructor. Messages encoded using an unknown schema will cause instances to throw a MissingSchemaException.

It is safe to continue using instances of this class after decode(java.io.InputStream, D) throws BadHeaderException or MissingSchemaException.

This class is thread-safe.

  • Constructor Details

    • BinaryMessageDecoder

      public BinaryMessageDecoder(GenericData model, Schema readSchema)
      Creates a new BinaryMessageEncoder that uses the given data model to construct datum instances described by the schema.

      The readSchema is as used the expected schema (read schema). Datum instances created by this class will be described by the expected schema.

      If readSchema is null, the write schema of an incoming buffer is used as read schema for that datum instance.

      The schema used to decode incoming buffers is determined by the schema fingerprint encoded in the message header. This class can decode messages that were encoded using the readSchema (if any) and other schemas that are added using addSchema(Schema).

      Parameters:
      model - the data model for datum instances
      readSchema - the Schema used to construct datum instances

    • BinaryMessageDecoder

      public BinaryMessageDecoder(GenericData model, Schema readSchema, SchemaStore resolver)
      Creates a new BinaryMessageEncoder that uses the given data model to construct datum instances described by the schema.

      The readSchema is used as the expected schema (read schema). Datum instances created by this class will be described by the expected schema.

      If readSchema is null, the write schema of an incoming buffer is used as read schema for that datum instance.

      The schema used to decode incoming buffers is determined by the schema fingerprint encoded in the message header. This class can decode messages that were encoded using the readSchema (if any), other schemas that are added using addSchema(Schema), or schemas returned by the resolver.

      Parameters:
      model - the data model for datum instances
      readSchema - the Schema used to construct datum instances
      resolver - a SchemaStore used to find schemas by fingerprint

  • Method Details

    • addSchema

      public void addSchema(Schema writeSchema)
      Adds a Schema that can be used to decode buffers.
      Parameters:
      writeSchema - a Schema to use when decoding buffers

    • decode

      public D decode(InputStream stream, D reuse) throws IOException
      Description copied from interface: MessageDecoder
      Deserialize a single datum from an InputStream.
      Parameters:
      stream - stream to read from
      reuse - a datum instance to reuse, avoiding instantiation if possible
      Returns:
      a datum read from the stream
      Throws:
      IOException