AnnotationMessage is a generated Protocol Buffers message and its native wire representation is protobuf binary. Spring's standard JSON conversion does not reliably reconstruct generated protobuf message classes, and separate service-local converters can easily drift.

AnnotationProtobufMessageConverter extends Spring's standard ProtobufMessageConverter. The DATAWAVE-packaged subclass is intentional: Spring Cloud Stream 3.2 filters most org.springframework.* converter beans from its custom converter collection, while accepting application-provided converter classes.

Module dependencies

annotation-messaging depends on annotation-api, which exposes the annotation model from datawave-core-annotation. Both annotation-service and annotation-cache-service depend on annotation-messaging, so the cache service receives annotation-api transitively. annotation-service also declares annotation-api directly.

Both services retain direct datawave-core-annotation dependencies because their source code uses its classes. Keep those versions aligned with the core version declared by annotation-api. annotation-cache-api contains cache-specific types and does not depend on the annotation model or messaging.

Using the module

Add the dependency to each annotation message producer or consumer:

<dependency>
    <groupId>gov.nsa.datawave.microservice</groupId>
    <artifactId>annotation-messaging</artifactId>
    <version>1.0.0-SNAPSHOT</version>
</dependency>

DATAWAVE microservices that scan datawave.microservice discover AnnotationMessagingConfiguration automatically. Applications with a narrower component scan should import it explicitly:

@Import(AnnotationMessagingConfiguration.class)

Every binding that carries AnnotationMessage must declare the protobuf content type:

spring:
  cloud:
    stream:
      bindings:
        annotationSource-out-0:
          content-type: application/x-protobuf
        annotationSink-in-0:
          content-type: application/x-protobuf

Use the same content type on all producers and consumers attached to a destination. Do not register another protobuf converter in an individual service.

Compatibility

The serialized contract is the protobuf schema supplied by datawave-core-annotation. Schema evolution must follow protobuf compatibility rules: do not reuse field numbers, and prefer additive changes with new field numbers.