Analyze deeply nested elasticsearch clusters using its client API

Question

I am using the Java API to return aggregates. Below is the structure I'm dealing with.

aggregations
top_models
   buckets
       key : "BMW"
      doc_count : 3
      top_models
           buckets
               key : "X5"
               doc_count : 2
              top_hits
                   source
                      model : X5
                      color : Red
                  source
                     model:X5
                    color : White
           key : "X3"
               doc_count : 1
              top_hits
                   source
                      model : X3
                      color : Red
      key : "Mercedes"
      doc_count : 2
      top_models
           buckets
               key : "Benz"
               doc_count : 1
               top_hits
                   source
                      model : Benz
                      color : Red

              key : "ML"
              doc_count : 1
              top_hits
                   source
                      model : ML
                      color : Black

I am trying to execute (toy) code to get all the results.

def getAggregations(aggres: Option[Aggregations]): Option[Iterable[Any]] = {


aggres map { agg =>


  val aggS = agg.asMap().asScala


  aggS map {


    case (name, termAgg: Terms) => getBuckets(Option(termAgg.getBuckets()))


    case (name, topHits: TopHits) =>


      val tHits = Option(topHits.getHits())


      tHits map { th => getTopHits(th.asScala)
    }


    case (h, a: InternalAvg) => println(h + "=>" + a.getValue());


  }





}


}





def getBuckets(buckets: Option[java.util.Collection[Bucket]]) = {


buckets map { bks =>


  val bksS = bks.asScala


  bksS map { b =>


    println("Bucket Key =>" + b.getKey())


    println("Doc count =>" + b.getDocCount())


    getAggregations(Option(b.getAggregations())


  }


  }

 }

need to fill out the final result for this class

case class FinalResponse(bucketName: String, count: Long, children: List[FinalResponse])

With a nested relationship between aggregates and buckets, it becomes confusing to get all the aggregation results. how do you approach this?

Answer 1

In my previous project, we use this method to deserialize complex objects from elastic search:

json- ( ) . Jacson json scala , pojo, .

java api - . .

val hits = qb.execute().actionGet().getHits().getHits().asScala
hits.map { hit =>
  (hit.getId, hit.getSourceAsString, hit.getVersion)
}