Coders

The CollectionComposer works like a usual PCollection for the coders. By default, the coder of the outputs is inferred from the output type descriptor.

To set a specific coder on the output of the current step, use setCoder, e.g. with an Avro GenericRecord:

final PCollection<GenericRecord> output = CollectionComposer.of(records)
        .apply("Enrich", MapElements
                .into(TypeDescriptor.of(GenericRecord.class))
                .via((GenericRecord record) -> enrich(record)))
        .setCoder(AvroCoder.of(GenericRecord.class, schema))
        .getResult()
        .output();

The failures always use the coder of the Failure class (Java serialization).