public ByteBuf serializeRequest(I message) throws IOException {
    switch (requestType) {
        case PROTOBUF:
            final PrototypeMarshaller<I> marshaller = (PrototypeMarshaller<I>) requestMarshaller;
            return serializeProto(marshaller, (Message) message);
        default:
            final CompositeByteBuf out = alloc.compositeBuffer();
            try (ByteBufOutputStream os = new ByteBufOutputStream(out)) {
                if (isProto) {
                    ByteStreams.copy(method.streamRequest(message), os);
                } else {
                    jsonMarshaller.serializeMessage(requestMarshaller, message, os);
                }
            }
            return out;
    }
}
 

public ByteBuf serializeResponse(O message) throws IOException {
    switch (responseType) {
        case PROTOBUF:
            final PrototypeMarshaller<O> marshaller =
                    (PrototypeMarshaller<O>) method.getResponseMarshaller();
            return serializeProto(marshaller, (Message) message);
        default:
            final CompositeByteBuf out = alloc.compositeBuffer();
            try (ByteBufOutputStream os = new ByteBufOutputStream(out)) {
                if (isProto) {
                    ByteStreams.copy(method.streamResponse(message), os);
                } else {
                    jsonMarshaller.serializeMessage(responseMarshaller, message, os);
                }
            }
            return out;
    }
}
 

@Test
public void introspection() throws Exception {
  Marshaller<Enum> enumMarshaller = ProtoLiteUtils.marshaller(Enum.getDefaultInstance());
  PrototypeMarshaller<Enum> prototypeMarshaller = (PrototypeMarshaller<Enum>) enumMarshaller;
  assertSame(Enum.getDefaultInstance(), prototypeMarshaller.getMessagePrototype());
  assertSame(Enum.class, prototypeMarshaller.getMessageClass());
}
 

@Override
public <T> T deserializeMessage(Marshaller<T> marshaller, InputStream is) throws IOException {
    final PrototypeMarshaller<T> prototypeMarshaller = (PrototypeMarshaller<T>) marshaller;
    final Message prototype = (Message) prototypeMarshaller.getMessagePrototype();
    final Message.Builder builder = prototype.newBuilderForType();
    delegate.mergeValue(is, builder);
    @SuppressWarnings("unchecked")
    final T cast = (T) builder.build();
    return cast;
}
 

@Nullable
private static Message marshallerPrototype(Marshaller<?> marshaller) {
    if (marshaller instanceof PrototypeMarshaller) {
        final Object prototype = ((PrototypeMarshaller<?>) marshaller).getMessagePrototype();
        if (prototype instanceof Message) {
            return (Message) prototype;
        }
    }
    return null;
}
 

@Test
public void introspection() throws Exception {
  Marshaller<Enum> enumMarshaller = ProtoLiteUtils.marshaller(Enum.getDefaultInstance());
  PrototypeMarshaller<Enum> prototypeMarshaller = (PrototypeMarshaller<Enum>) enumMarshaller;
  assertSame(Enum.getDefaultInstance(), prototypeMarshaller.getMessagePrototype());
  assertSame(Enum.class, prototypeMarshaller.getMessageClass());
}
 

private static MessageType marshallerType(Marshaller<?> marshaller) {
    return marshaller instanceof PrototypeMarshaller ? MessageType.PROTOBUF : MessageType.UNKNOWN;
}