Fetching specific fields in ES 5.X Java client API

[jprante (Jörg Prante)]

@teemu

It seems to me that I store the value as long, curl gets it as long, Java API used to get is as long but now gets it as formatted date string.

So this is what I was wondering. Is this some change in the Java API, and Is there some way to get the long without going through all the conversions?

The document source contains the content you sent over the API, so you see the long value in return when you sent a long. In Java, you can extract those values by hit.sourceAsMap().get(...)

Accessing a field of a specific type over the Java API is controlled by the value conversions of Elasticsearch mapping specification. So you will see the expected date format because of the date type in the mapping.

If you index dates before Jan 1, 1970:, e.g.

field("doc_date", -9184838400000 )

you will get negative long applying toEpochMilli() as specified by the java.time.Instant class.

SearchResponse response = client.prepareSearch()
  .setQuery(matchAllQuery())
  .addStoredField("_source")
  .addStoredField("doc_date")
  .execute().actionGet()

println response

response.hits.hits.each { hit ->
    println hit.sourceAsMap().get("doc_date")  // numeric
    println hit.fields.get("doc_date").value() // date string
    Instant instant = Instant.parse(hit.fields.get("doc_date").value())
    long millis = instant.toEpochMilli() // parsed date
    println millis
}

This will give a result like

{"took":1,"timed_out":false,"_shards":{"total":5,"successful":5,"failed":0},"hits":{"total":1,"max_score":1.0,"hits":[{"_index":"test","_type":"test","_id":"1","_score":1.0,"_source":{"doc_date":-9184838400000},"fields":{"doc_date":["1678-12-11T00:00:00.000Z"]}}]}}

Note the difference between _source and doc_date.