Support for UUID columns

[jze]

I try to write a UUID column.

My first attempt to define the type was

types.add(Types.required(BINARY).as(LogicalTypeAnnotation.uuidType()).named("id"));

However, that does not work:

Exception in thread "main" java.lang.IllegalStateException: UUID can only annotate FIXED_LEN_BYTE_ARRAY(16)
	at org.apache.parquet.Preconditions.checkState(Preconditions.java:166)
	at org.apache.parquet.schema.Types$BasePrimitiveBuilder$1.checkFixedPrimitiveType(Types.java:594)
	at org.apache.parquet.schema.Types$BasePrimitiveBuilder$1.visit(Types.java:464)
	at org.apache.parquet.schema.LogicalTypeAnnotation$UUIDLogicalTypeAnnotation.accept(LogicalTypeAnnotation.java:1014)
	at org.apache.parquet.schema.Types$BasePrimitiveBuilder.build(Types.java:442)
	at org.apache.parquet.schema.Types$BasePrimitiveBuilder.build(Types.java:334)
	at org.apache.parquet.schema.Types$Builder.named(Types.java:313)

Next I tried to define the type like this:

types.add(Types.required(FIXED_LEN_BYTE_ARRAY).length(16).as(LogicalTypeAnnotation.uuidType()).named("id"));

The definition of the schema works. However, when I try to write a value

byte[] uuidBytes = ByteBuffer.allocate(16)
                    .putLong(uuid.getMostSignificantBits())
                    .putLong(uuid.getLeastSignificantBits())
                    .array();
valueWriter.write("id", uuidBytes);

it fails because FIXED_LEN_BYTE_ARRAY is not supported:

Exception in thread "main" java.lang.UnsupportedOperationException: We don't support writing FIXED_LEN_BYTE_ARRAY
	at blue.strategic.parquet.ParquetWriter$SimpleWriteSupport.writeField(ParquetWriter.java:161)