How to use

getDescriptorForType

method

in

com.google.protobuf.Message$Builder

@SuppressWarnings("unchecked")
@Override
public Mono<Void> write(Publisher<? extends Message> inputStream, ResolvableType elementType,
    @Nullable MediaType mediaType, ReactiveHttpOutputMessage message, Map<String, Object> hints) {
  try {
    Message.Builder builder = getMessageBuilder(elementType.toClass());
    Descriptors.Descriptor descriptor = builder.getDescriptorForType();
    message.getHeaders().add(X_PROTOBUF_SCHEMA_HEADER, descriptor.getFile().getName());
    message.getHeaders().add(X_PROTOBUF_MESSAGE_HEADER, descriptor.getFullName());
    if (inputStream instanceof Flux) {
      if (mediaType == null) {
        message.getHeaders().setContentType(((HttpMessageEncoder<?>)getEncoder()).getStreamingMediaTypes().get(0));
      }
      else if (!ProtobufEncoder.DELIMITED_VALUE.equals(mediaType.getParameters().get(ProtobufEncoder.DELIMITED_KEY))) {
        Map<String, String> parameters = new HashMap<>(mediaType.getParameters());
        parameters.put(ProtobufEncoder.DELIMITED_KEY, ProtobufEncoder.DELIMITED_VALUE);
        message.getHeaders().setContentType(new MediaType(mediaType.getType(), mediaType.getSubtype(), parameters));
      }
    }
    return super.write(inputStream, elementType, mediaType, message, hints);
  }
  catch (Exception ex) {
    return Mono.error(new DecodingException("Could not read Protobuf message: " + ex.getMessage(), ex));
  }
}

@SuppressWarnings("unchecked")
@Override
public Mono<Void> write(Publisher<? extends Message> inputStream, ResolvableType elementType,
    @Nullable MediaType mediaType, ReactiveHttpOutputMessage message, Map<String, Object> hints) {
  try {
    Message.Builder builder = getMessageBuilder(elementType.toClass());
    Descriptors.Descriptor descriptor = builder.getDescriptorForType();
    message.getHeaders().add(X_PROTOBUF_SCHEMA_HEADER, descriptor.getFile().getName());
    message.getHeaders().add(X_PROTOBUF_MESSAGE_HEADER, descriptor.getFullName());
    if (inputStream instanceof Flux) {
      if (mediaType == null) {
        message.getHeaders().setContentType(((HttpMessageEncoder<?>)getEncoder()).getStreamingMediaTypes().get(0));
      }
      else if (!ProtobufEncoder.DELIMITED_VALUE.equals(mediaType.getParameters().get(ProtobufEncoder.DELIMITED_KEY))) {
        Map<String, String> parameters = new HashMap<>(mediaType.getParameters());
        parameters.put(ProtobufEncoder.DELIMITED_KEY, ProtobufEncoder.DELIMITED_VALUE);
        message.getHeaders().setContentType(new MediaType(mediaType.getType(), mediaType.getSubtype(), parameters));
      }
    }
    return super.write(inputStream, elementType, mediaType, message, hints);
  }
  catch (Exception ex) {
    return Mono.error(new DecodingException("Could not read Protobuf message: " + ex.getMessage(), ex));
  }
}

               throws ParseException {
FieldDescriptor field;
final Descriptor type = builder.getDescriptorForType();
ExtensionRegistry.ExtensionInfo extension = null;

public static final IRepeatedFieldValueBuilder<Object> getBuilderForRepeatedAttribute(
  final Message.Builder builder, final FieldDescriptor field) {
 if (!field.isRepeated()) {
  throw new IllegalArgumentException("the field must be repeated");
 } else if (builder.getDescriptorForType() != field.getContainingType()) {
  throw new IllegalArgumentException("the field doen't belong to this type");
 }
 if (field.getJavaType() == JavaType.MESSAGE) {
  throw new IllegalArgumentException("the field must be of a non-Message type");
 }
 return new RepeatedFieldValueBuilder<Message.Builder, Object>(builder, field);
}

public static void setFieldByName(Message.Builder builder, String name, Object value) {
 FieldDescriptor fieldDescriptor = builder.getDescriptorForType().findFieldByName(name);
 if (value == null) {
  builder.clearField(fieldDescriptor);
 } else {
  builder.setField(fieldDescriptor, value);
 }
}

/**
 * Merges all fields specified by this FieldMaskTree from {@code source} to {@code destination}.
 */
void merge(Message source, Message.Builder destination, FieldMaskUtil.MergeOptions options) {
 if (source.getDescriptorForType() != destination.getDescriptorForType()) {
  throw new IllegalArgumentException("Cannot merge messages of different types.");
 }
 if (root.children.isEmpty()) {
  return;
 }
 merge(root, "", source, destination, options);
}

private void mergeStruct(JsonElement json, Message.Builder builder)
  throws InvalidProtocolBufferException {
 Descriptor descriptor = builder.getDescriptorForType();
 FieldDescriptor field = descriptor.findFieldByName("fields");
 if (field == null) {
  throw new InvalidProtocolBufferException("Invalid Struct type.");
 }
 mergeMapField(field, json, builder);
}

private void merge(JsonElement json, Message.Builder builder)
  throws InvalidProtocolBufferException {
 WellKnownTypeParser specialParser =
   wellKnownTypeParsers.get(builder.getDescriptorForType().getFullName());
 if (specialParser != null) {
  specialParser.merge(this, json, builder);
  return;
 }
 mergeMessage(json, builder, false);
}

private void mergeWrapper(JsonElement json, Message.Builder builder)
  throws InvalidProtocolBufferException {
 Descriptor type = builder.getDescriptorForType();
 FieldDescriptor field = type.findFieldByName("value");
 if (field == null) {
  throw new InvalidProtocolBufferException("Invalid wrapper type: " + type.getFullName());
 }
 builder.setField(field, parseFieldValue(field, json, builder));
}

private void merge(JsonElement json, Message.Builder builder)
  throws InvalidProtocolBufferException {
 WellKnownTypeParser specialParser =
   wellKnownTypeParsers.get(builder.getDescriptorForType().getFullName());
 if (specialParser != null) {
  specialParser.merge(this, json, builder);
  return;
 }
 mergeMessage(json, builder, false);
}

  private synchronized Message.Builder removeUnwantedServiceTempus(final Message.Builder builder) {
    // if unknown keep everything
    if(serviceTempus == ServiceTempus.UNKNOWN) {
      return builder;
    }
    
    Descriptors.Descriptor descriptorForType = builder.getDescriptorForType();
    descriptorForType.getFields().stream().filter((field) -> (field.getType() == Descriptors.FieldDescriptor.Type.MESSAGE)).filter((field) -> (!fieldsToKeep.contains(field.getName()))).forEachOrdered((field) -> {
      builder.clearField(field);
    });
    return builder;
  }
}

private void mergeWrapper(JsonElement json, Message.Builder builder)
  throws InvalidProtocolBufferException {
  Descriptor type = builder.getDescriptorForType();
  FieldDescriptor field = type.findFieldByName("value");
  if (field == null) {
    throw new InvalidProtocolBufferException("Invalid wrapper type: " + type.getFullName());
  }
  builder.setField(field, parseFieldValue(field, json, builder));
}

private void mergeStruct(JsonElement json, Message.Builder builder)
  throws InvalidProtocolBufferException {
  Descriptor descriptor = builder.getDescriptorForType();
  FieldDescriptor field = descriptor.findFieldByName("fields");
  if (field == null) {
    throw new InvalidProtocolBufferException("Invalid Struct type.");
  }
  mergeMapField(field, json, builder);
}

/**
 * Gets a list of {@link Descriptors.FieldDescriptor} associated with the {@link Message.Builder}
 *
 * @param protoBuilder {@link Message.Builder} instance
 * @return list of {@link Descriptors.FieldDescriptor} associated with the {@link Message.Builder}
 */
private static List<Descriptors.FieldDescriptor> getFieldDescriptors(Message.Builder protoBuilder) {
  return protoBuilder.getDescriptorForType().getFields();
}

 @Override
 protected void populate(V builder, JsonParser parser, DeserializationContext context) throws IOException {
  FieldDescriptor field = builder.getDescriptorForType().findFieldByName("value");
  Object value = readValue(builder, field, null, parser, context);
  builder.setField(field, value);
 }
}

public FieldDescriptor getFieldDescriptor(Class<? extends TBase<?, ?>> thriftClass,
                     String fieldName) {
 checkState(thriftClass);
 Descriptors.Descriptor descriptor = getBuilder(thriftClass).getDescriptorForType();
 return descriptor.findFieldByName(fieldName);
}

private void mergeListValue(JsonElement json, Message.Builder builder)
  throws InvalidProtocolBufferException {
 Descriptor descriptor = builder.getDescriptorForType();
 FieldDescriptor field = descriptor.findFieldByName("values");
 if (field == null) {
  throw new InvalidProtocolBufferException("Invalid ListValue type.");
 }
 mergeRepeatedField(field, json, builder);
}

  Message.Builder builder) throws ParseException {
FieldDescriptor field;
Descriptor type = builder.getDescriptorForType();
ExtensionRegistry.ExtensionInfo extension = null;
boolean unknown = false;

@Override
public Descriptors.Descriptor getDescriptorForType() {
 return builder.getDescriptorForType();
}

/**
 * Gets a list of {@link Descriptors.FieldDescriptor} associated with the {@link Message.Builder}
 *
 * @param protoBuilder {@link Message.Builder} instance
 * @return list of {@link Descriptors.FieldDescriptor} associated with the {@link Message.Builder}
 */
private static List<Descriptors.FieldDescriptor> getFieldDescriptors(Message.Builder protoBuilder) {
  return protoBuilder.getDescriptorForType().getFields();
}