Styjun

So I have a collection of news articles scored by page views from Mongo DB that I query like this:

// To directly connect to the default server localhost on port 27017
val mongoClient: MongoClient = MongoClient("mongodb://localhost:27017/")
val database: MongoDatabase = mongoClient.getDatabase("Posts")
var collection: MongoCollection[Document] = database.getCollection("news")

collection.find(equal("id","id123")).limit(5).subscribe((doc: Document)=>println(s"$doc.get("views")"))

This prints:

Some(BsonInt32value=66043)
Some(BsonInt32value=66306)
Some(BsonInt32value=66336)
Some(BsonInt32value=66365)
Some(BsonInt32value=66384)

So now I want to collect all of those values into an array, which I have tried to do via this line of code:

var scores = collection.find(equal("id","id123")).limit(5).subscribe((doc: Document)=>doc.get("score").map(_.asInt32().getValue).collect())

But the .collect() does not work.

What is the best way to turn the Mongo field into an array of Ints?

I figured out a solution, though I don't completely understand it:

import org.mongodb.scala._
import org.mongodb.scala.model.Filters._
import org.mongodb.scala.model.Projections._

object main extends App 
 //Connect to Mongo Client and DB
 val mongoClient: MongoClient = MongoClient("mongodb://localhost:27017/")
 val database: MongoDatabase = mongoClient.getDatabase("MyDatabase")

 //Get Collection
 val collection: MongoCollection[Document] = database.getCollection("collectionName")

 //Returns the object with specified fields in projection 
 //as a Future observable containing MongoDB Documents
 val collScores = collection.find(equal("id","id123")).limit(5).projection(fields(include("id", "score", "time"), excludeId()))

 //Maps the document fields to tuples and converts them 
 //to non BSon values since they are easier to work with 
 //than future observables.
 val listMapScores = collScores.map(doc=>(doc("id").asString.getValue,doc("score").asInt32.getValue,doc("time").asDouble.getValue)).collect().results().head 

I am not sure why you need to do both results() and then head in the last line. If you don't take the head you end up with a Seq[Seq(String,Int)]]. From what I can tell the future observable contains the same values regardless of if you take the head or the Nth term in the series.