[AVRO-432] add @Nullable annotation to specify union with null

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.3.0
• Fix Version/s: 1.3.1
• Component/s: java
• Assignee: Doug Cutting
• Reporter: Doug Cutting
• Created: 26/Feb/10 00:12
• Updated: 22/Mar/10 23:19
• Resolved: 03/Mar/10 23:29

Description

HDFS now includes a class (HdfsFileStatus) with a field (symlink) whose type is byte[] but which is null for non-symlinks. For most other types, we could annotate this with something like @Union(

{Void.class, Foo.class}

) to declare that the field may be null. But there is unfortunately no way to refer to the class of byte[] in an annotation. So, instead, I propose to add an annotation that permits the specification of an arbitrary schema. In this case, the annotation would then be @AvroSchema("[\"null\",\bytes\"").

Issue Links

• blocks: HDFS-892 optionally use Avro for namenode RPC