[AVRO-997] Generic API should require GenericEnumSymbol when writing Avro Enums

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.5.1
• Fix Version/s: 1.8.0
• Hadoop Flags: Incompatible change

Release Note

Previous versions of Avro's Java library allowed String and Java Enum values to be used in the Generic API when writing fields that are Avro Enums. This change makes the Generic API strict by requiring GenericEnumSymbol instances. To ease updating downstream projects it also adds a constructor for GenericData.EnumSymbol that calls toString on a passed Object.

• Assignee: Sean Busbey
• Reporter: Aaron Kimball
• Created: 18/Jan/12 16:40
• Updated: 07/Nov/19 09:37
• Resolved: 03/Oct/14 20:34

Description

I have a schema like:

[
{
  "type": "enum",
  "name": "Gender",
  "symbols": ["M", "F"]
},

{
  "type" : "record",
  "name" : "Foo",
  "fields" : [
    { "type" : ["Gender", "null"], "name" : "gender" },
    ...
  ]
}
]

I build a record like Foo foo = new Foo(); foo.gender = Gender.M;

When I go to serialize this, I get:

Not in union [{"type":"enum","name":"Gender","symbols":["M","F"]},"null"]: M
	at org.apache.avro.generic.GenericData.resolveUnion(GenericData.java:482)
	at org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:70)
	at org.apache.avro.generic.GenericDatumWriter.writeRecord(GenericDatumWriter.java:104)
	at org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:65)
	at org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:57)

Issue Links

• is related to: PIG-5056 Fix AvroStorage writing enums
• relates to: AVRO-2602 Updating breaks backward compatibility by throwing AvroTypeException in some cases
• relates to: HIVE-3538 Avro SerDe can't handle Nullable Enums