how to store nested fields in elasticsearch - elasticsearch

Question

I am using Java High Level REST client. Here is the link to its documentation
I have created a client.
trait HighLevelRestClient {
def elasticSearchClient(): RestHighLevelClient = {
new RestHighLevelClient(
RestClient.builder(
new HttpHost("localhost", ElasticSearchPort, "http")))
}
}
While indexing the data, the nested fields are being stored as String. The following code explains how the index is being created:
val indexRequest = new IndexRequest("my-index", "test-type").source(
"person", person,
"date", DateTime.now()
)
where, person is a case class, represented as:
Person(personId: String, name: String, address: Address)
and Address is itself a case class, represented as:
Address(city: String, zip: Int)
My application requires person to be stored as key-value pair, so that it's fields are searchable. But, when I am using the above code, it is being stored as String.
{
"person" : "Person(my-id, my-name, Address(my-city, zip-value))",
"date" : "2017-12-12"
}
and required structure is:
{
"person" : {
"personId" : "my-id",
"name" : "person-name",
"address": {
"city" : "city-name",
"zip" : 12345
}
},
"date" : "2017-12-12"
}
I hope I have framed the question well. Any help would be appreciated. Thanks!

Answer 1

You are almost there. To achieve your goal you need to:
Serialize the object to JSON on your side
Specify the content type of the request
It is actually described in the page of the Index API.
A convenient library to serialize case classes into JSON is for example json4s (you can see some examples of serialization here).
Your code might look like the following:
import org.apache.http.HttpHost
import org.elasticsearch.action.index.IndexRequest
import org.elasticsearch.client.{RestClient, RestHighLevelClient}
import org.elasticsearch.common.xcontent.XContentType
import org.joda.time.DateTime
import org.json4s.NoTypeHints
import org.json4s.jackson.Serialization
import org.json4s.jackson.Serialization.write
case class Address(city: String, zip: Int)
case class Person(personId: String, name: String, address: Address)
case class Doc(person: Person, date: String)
object HighClient {
def main(args: Array[String]): Unit = {
val client = new RestHighLevelClient(
RestClient.builder(
new HttpHost("localhost", 9206, "http")))
implicit val formats = Serialization.formats(NoTypeHints)
val doc = Doc(
Person("blah1", "Peter Parker", Address("New-York", 33755)),
DateTime.now().toString
)
val indexRequest = new IndexRequest("my-index", "test-type").source(
write(doc), XContentType.JSON
)
client.index(indexRequest)
client.close()
}
}
Note that in this case:
new IndexRequest("my-index", "test-type").source(
write(doc), XContentType.JSON
)
this function will be used: public IndexRequest source(String source, XContentType xContentType)
While in your case:
new IndexRequest("my-index", "test-type").source(
"person", person,
"date", DateTime.now()
)
it will call public IndexRequest source(Object... source).
Hope that helps!