update es doc

updateESdoc.scala

final def updateClusterSize(docId: String, newClusterSize: Int) : ListenableActionFuture[UpdateResponse] = {
    val fields = client.prepareGet(indexName, typeName, docId)
                         .setFields("_timestamp")
                         .execute().actionGet().fields()
    val oldTimestamp = if (fields == null)
                         (new Date()).getTime
                       else
                         fields.get("_timestamp").value()
    client.prepareUpdate(indexName, typeName, docId)
          .setScript("""
                       ctx._source.clusterSize = newClusterSize;
                       ctx._timestamp = oldTimestamp;
                     """)
          .addScriptParam("newClusterSize", newClusterSize)
          .addScriptParam("oldTimestamp", oldTimestamp.toString)
          .execute()
  }