Helidon gRPC supports Protobuf out of the box. The Protobuf marshaller will be used by default for any request and response classes that extend com.google.protobuf.MessageLite, which is the case for all classes generated from a proto file using protoc compiler.
That means that you don’t need any special handling or configuration in order to support Protobuf serialization of requests and responses.
Helidon makes the use of custom marshallers trivial and provides one custom implementation, JsonbMarshaller, out of the box.
You can also easily implement your own marshaller to support serialization formats that are not supported natively
by Helidon, by implementing Marshaller and MarshallerSupplier interfaces. As an example, check out
the source code of the built-in marshaller:
JsonbMarshaller.java.
Furthermore, Oracle Coherence CE provides a marshaller for a highly optimized, binary, platform independent Portable Object Format (POF). You can find more information about POF in Coherence documentation