Jackson Custom JSON Serializer

MyDtoSerializer.java

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;

import java.io.IOException;

public class UiNotificationSerializer extends JsonSerializer<MyDto> {

	@Override public void serialize(MyDto dto, JsonGenerator generator, SerializerProvider serializerProvider) throws IOException, JsonProcessingException {
	  
		generator.writeStartObject();
		generator.writeNumberField("id", dto.getId());
		Integer brandId = dto.getBrandId();
		if (brandId != null) {
			generator.writeNumberField("brandId", dto.getBrandId());
		} else {
			generator.writeNullField("brandId");
		}
		String message = dto.getMessage();
		if (message != null) {
			generator.writeStringField("message", message);
		} else {
			generator.writeNullField("message");
		}
		generator.writeEndObject();
	}
}