Get a typed value from an Avro GenericRecord

Question

Given a GenericRecord, what is the recommended way to retrieve a typed value, as opposed to an Object? Are we expected to cast the values, and if so what is the mapping from Avr

Answer 1

Avro has eight primitive types and five complex types (excluding unions which are a combination of other types). The following table maps these 13 Avro types to their input interfaces (the Java types which can be put into a GenericRecord) and their output implementations (the concrete Java types which are returned by a get from a GenericRecord). The values apply to Avro 1.7.7.

╔═══════════╦════════════════════════╦═══════════════════════════╗ ║ Avro Type ║ Input Interface ║ Output Implementation ║ ╠═══════════╬════════════════════════╬═══════════════════════════╣ ║ null ║ ║ null ║ ║ boolean ║ java.lang.Boolean ║ java.lang.Boolean ║ ║ int ║ java.lang.Integer ║ java.lang.Integer ║ ║ long ║ java.lang.Long ║ java.lang.Long ║ ║ float ║ java.lang.Float ║ java.lang.Float ║ ║ double ║ java.lang.Double ║ java.lang.Double ║ ║ bytes ║ java.nio.ByteBuffer ║ java.nio.HeapByteBuffer ║ ║ string ║ java.lang.CharSequence ║ org.apache.avro.util.Utf8 ║ ║ record ║ *.GenericRecord ║ *.GenericData$Record ║ ║ enum ║ java.lang.CharSequence ║ *.GenericData$EnumSymbol ║ ║ array ║ java.util.Collection ║ *.GenericData$Array ║ ║ map ║ java.util.Map ║ java.util.HashMap ║ ║ fixed ║ *.GenericFixed ║ *.GenericData$Fixed ║ ╚═══════════╩════════════════════════╩═══════════════════════════╝ * == org.apache.avro.generic

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In Avro 1.8.0, the enum type requires a GenericEnumSymbol. It no longer accepts CharSequence.