Supply a custom `Sort.Order` providing Elasticsearch specific parameters

Spring Data Elasticsearch should supply a Sort.Order derived class that can provide custom parameters like ignore_unmapped (see #1908) for an example where this is needed

[sothawo]

it would be nice for Spring Data ES to translate something down into this ES code: SortOrder sortOrder = SortBuilders.fieldSort("created").unmappedType("long").order();

that was exactly the point of this issue. So now it is possible to do

import org.springframework.data.elasticsearch.core.query.Order;

Sort sort = Sort.by(new Order(Sort.Direction.ASC, "created").withUnmappedType("long"));

and use that sort in a Pageable as parameter or whatever.

How is this date field mapped in your index? Is it really unmapped? What does /<indexname>/_mappings show for that property? If you have data for that property in the index then it will be surely mapped, so adding an unmapped type to a sort has not effect. What is the problem that you have with the sorting?

As for the temporal types: java.util.Date is an instance in time in UTC time zone. A LocalDateTime does not have a timezone, so it cannot be instantiated from a long. The appropriate data type would be java.time.Instant

[alan-czajkowski]

@sothawo I’m using Spring 5.3 and Spring Data ES 4.3

I, personally, think it is reasonable to make java.time.Instant behave like java.util.Date since they are very closely related and because, from an engineering stand-point, normalizing your date-time’s to UTC is actually good practice, as the default behaviour … of course, the default isn’t always desired, but some default can be reasonable … but since this is a “bigger” problem that falls under the Spring Data umbrella (not just Spring Data Elasticsearch) then I’m not about to fight for this since it’s not a battle I have time for

1. would this be a reasonable definition for my “created” field, given that I want all date-times stored in ES normalized to UTC:

  @Field(type = FieldType.Date, format = DateFormat.epoch_millis)
  private Instant created;

1. do you recommend that every field have an explicit @Field annotation?