How to use

newBuilderForField

method

in

com.google.protobuf.Message$Builder

@Override
public Object parseMessage(
  CodedInputStream input,
  ExtensionRegistryLite extensionRegistry,
  Descriptors.FieldDescriptor field,
  Message defaultInstance)
  throws IOException {
 Message.Builder subBuilder;
 // When default instance is not null. The field is an extension field.
 if (defaultInstance != null) {
  subBuilder = defaultInstance.newBuilderForType();
 } else {
  subBuilder = builder.newBuilderForField(field);
 }
 if (!field.isRepeated()) {
  Message originalMessage = (Message) getField(field);
  if (originalMessage != null) {
   subBuilder.mergeFrom(originalMessage);
  }
 }
 input.readMessage(subBuilder, extensionRegistry);
 return subBuilder.buildPartial();
}

 subBuilder = defaultInstance.newBuilderForType();
} else {
 subBuilder = builder.newBuilderForField(field);
 subBuilder = defaultInstance.newBuilderForType();
} else {
 subBuilder = builder.newBuilderForField(field);

 subBuilder = builder.newBuilderForField(field);
} else {
 subBuilder = extension.defaultInstance.newBuilderForType();

@Override
public MergeTarget newMergeTargetForField(
  Descriptors.FieldDescriptor field, Message defaultInstance) {
 if (defaultInstance != null) {
  return new BuilderAdapter(
    defaultInstance.newBuilderForType());
 } else {
  return new BuilderAdapter(builder.newBuilderForField(field));
 }
}

  subBuilder = builder.newBuilderForField(field);
} else {
  subBuilder = extension.defaultInstance.newBuilderForType();

sb.append("\",\"values\":[");
Descriptors.FieldDescriptor childDescriptor = requestDesc.findFieldByName(fd.getName());
Message.Builder subMessageBuilder = builder.newBuilderForField(childDescriptor);
Message subMessage = subMessageBuilder.build();
sb.append(getProtobufClassFieldDescriptions(subMessage.getClass(), visited));

@Override
public MergeTarget newMergeTargetForField(
  Descriptors.FieldDescriptor field, Message defaultInstance) {
 if (defaultInstance != null) {
  return new BuilderAdapter(
    defaultInstance.newBuilderForType());
 } else {
  return new BuilderAdapter(builder.newBuilderForField(field));
 }
}

private Message.Builder createSubBuilder(Message.Builder builder,
    FieldDescriptor field, 
    ExtensionRegistry.ExtensionInfo extension) {
  
  Message.Builder subBuilder;
  if (extension == null) {
    subBuilder = builder.newBuilderForField(field);
  } else {
    subBuilder = extension.defaultInstance.newBuilderForType();
  }
  return subBuilder;
}

public MergeTarget newMergeTargetForField(Descriptors.FieldDescriptor field,
  Message defaultInstance) {
 if (defaultInstance != null) {
  return new BuilderAdapter(
    defaultInstance.newBuilderForType());
 } else {
  return new BuilderAdapter(builder.newBuilderForField(field));
 }
}

@Override
public Message.Builder newInstance() {
 return parent.newBuilderForField(field);
}

public Class<? extends Message> getElementMessageType() {
 return parent.newBuilderForField(field).buildPartial().getClass();
}

@SuppressWarnings("unchecked")
private static void putMapEntry(
  Message.Builder builder, FieldDescriptor field, Object key, Object value) {
 Message.Builder entryBuilder = builder.newBuilderForField(field);
 FieldDescriptor keyField = entryBuilder.getDescriptorForType().findFieldByName("key");
 FieldDescriptor valueField = entryBuilder.getDescriptorForType().findFieldByName("value");
 entryBuilder.setField(keyField, key);
 entryBuilder.setField(valueField, value);
 List<Message> entries =
   removeEntryWithKeyIfPresent((List<Message>) builder.getField(field), key);
 entries.add(entryBuilder.build());
 builder.setField(field, entries);
}

/**
 * Constructs a sub-builder for an added element of the repeated message field, and calls action
 * on it.
 */
public Builder withAddedBuilder(FieldDescriptor field, BuildAction action) {
 Message.Builder repeatedFieldBuilder = configBuilder.newBuilderForField(field);
 Builder elementBuilder =
   new Builder(repeatedFieldBuilder.build(), repeatedFieldBuilder, locations);
 action.accept(elementBuilder);
 // Call build so locations map is updated.
 ConfigSource configSource = elementBuilder.build();
 // Update the list with the built element
 configBuilder.addRepeatedField(field, configSource.configMessage);
 return this;
}

public Class<? extends Message.Builder> getElementBuilderType() {
 return parent.newBuilderForField(field).getClass();
}

@Override
public Object parseMessageFromBytes(
  ByteString bytes,
  ExtensionRegistryLite extensionRegistry,
  Descriptors.FieldDescriptor field,
  Message defaultInstance)
  throws IOException {
 Message.Builder subBuilder;
 // When default instance is not null. The field is an extension field.
 if (defaultInstance != null) {
  subBuilder = defaultInstance.newBuilderForType();
 } else {
  subBuilder = builder.newBuilderForField(field);
 }
 if (!field.isRepeated()) {
  Message originalMessage = (Message) getField(field);
  if (originalMessage != null) {
   subBuilder.mergeFrom(originalMessage);
  }
 }
 subBuilder.mergeFrom(bytes, extensionRegistry);
 return subBuilder.buildPartial();
}

public Message.Builder newBuilderForField(Descriptors.FieldDescriptor fd) {
 return internalBuilder.newBuilderForField(fd);
}

@Override
public Object parseGroup(
  CodedInputStream input,
  ExtensionRegistryLite extensionRegistry,
  Descriptors.FieldDescriptor field,
  Message defaultInstance)
  throws IOException {
 Message.Builder subBuilder;
 // When default instance is not null. The field is an extension field.
 if (defaultInstance != null) {
  subBuilder = defaultInstance.newBuilderForType();
 } else {
  subBuilder = builder.newBuilderForField(field);
 }
 if (!field.isRepeated()) {
  Message originalMessage = (Message) getField(field);
  if (originalMessage != null) {
   subBuilder.mergeFrom(originalMessage);
  }
 }
 input.readGroup(field.getNumber(), subBuilder, extensionRegistry);
 return subBuilder.buildPartial();
}

/**
 * Constructs a sub-builder for an added element of the repeated message field, and calls action
 * on it.
 */
public Builder withAddedBuilder(FieldDescriptor field, BuildAction action) {
 Message.Builder repeatedFieldBuilder = configBuilder.newBuilderForField(field);
 Builder elementBuilder =
   new Builder(repeatedFieldBuilder.build(), repeatedFieldBuilder, locations);
 action.accept(elementBuilder);
 // Call build so locations map is updated.
 ConfigSource configSource = elementBuilder.build();
 // Update the list with the built element
 configBuilder.addRepeatedField(field, configSource.configMessage);
 return this;
}

/**
 * Constructs a sub-builder for a element at given index of the repeated message field, and
 * calls action on it.
 */
public Builder withBuilderAt(FieldDescriptor field, int index, BuildAction action) {
 Message.Builder repeatedFieldBuilder = configBuilder.newBuilderForField(field);
 repeatedFieldBuilder.mergeFrom((Message) configBuilder.getRepeatedField(field, index));
 Builder elementBuilder =
   new Builder(repeatedFieldBuilder.build(), repeatedFieldBuilder, locations);
 action.accept(elementBuilder);
 // Call build so locations map is updated.
 ConfigSource configSource = elementBuilder.build();
 // Update the list with the built element
 configBuilder.setRepeatedField(field, index, configSource.configMessage);
 return this;
}

@SuppressWarnings("unchecked")
private static void putMapEntry(
  Message.Builder builder, FieldDescriptor field, Object key, Object value) {
 Message.Builder entryBuilder = builder.newBuilderForField(field);
 FieldDescriptor keyField = entryBuilder.getDescriptorForType().findFieldByName("key");
 FieldDescriptor valueField = entryBuilder.getDescriptorForType().findFieldByName("value");
 entryBuilder.setField(keyField, key);
 entryBuilder.setField(valueField, value);
 List<Message> entries =
   removeEntryWithKeyIfPresent((List<Message>) builder.getField(field), key);
 entries.add(entryBuilder.build());
 builder.setField(field, entries);
}