DocumentAdapters converts sort values to string

[whalewired]

When upgrading from 4.2.12 to 5.1.5 search_after on sorted date fields, that does not specify pattern, no longer works.

In 4.2.12 the returned sort value was Long (epoch_millis).

In 5.1.5 it is converted to a String.

It happens her:

org.springframework.data.elasticsearch.client.elc.DocumentAdapters

return new SearchDocumentAdapter(document, score, hit.sort().stream().map(TypeUtils::toString).toArray(),
				documentFields, highlightFields, innerHits, nestedMetaData, explanation, matchedQueries, hit.routing());

If that String is used in search_after Elasticsearch fails with "failed to parse date field".

When it stays as a Long it works fine.

One could add "format" pattern to the sort part to fix this so it uses that pattern consistently, but the use of Long also worked, so my question is, why are these converted to string?

[sothawo]

I have to check into this one. I remember that the new Elasticsearch client in the beginning used to always return the sort values in a String array, but they may have changed this in the meantime.

[whalewired]

Will this go into 5.1.7?

[sothawo]

Will this go into 5.1.7?

yes