Example for testing MongoDB GeoIndex

Test

mport com.mongodb.{Mongo, BasicDBObject, DBObject}
import scala.collection.convert.WrapAsJava

object Test extends App with WrapAsJava {
  val mongo = new Mongo("host").getDB("TestGeoDB").getCollection("city")

  private val line2Bson: String => DBObject = line => {
    val Array(_id, country, city, lati, longi, elevation) = line.split(";").map(_.replace("\"", ""))
    new BasicDBObject(
      mapAsJavaMap(Map(
        "_id" -> _id.toInt,
        "country" -> country.toString,
        "city" -> city.toString,
        "loc" -> new BasicDBObject(
          mapAsJavaMap(Map(
            "type" -> "Point",
            "coordinates" -> Array(longi.toDouble, lati.toDouble)
          ))),
        "ele" -> elevation.toDouble
      )))
  }

  //Insert
  /*Source.fromFile(
    new File("/home/focusj/Git/ScalaSpec/src/main/resources/World_Cities_Location_table.csv")
  ).getLines.map(l => line2Bson(l)).grouped(40).foreach{ docs => mongo.insert(docs)}*/

  //LanZhou: 103.7922211, 36.0563889
  //ShangHai: 121.4580536, 31.2222222
  val query1 = new BasicDBObject(
    mapAsJavaMap(Map(
      "loc" -> new BasicDBObject(
        mapAsJavaMap(
          Map("$geoWithin" -> new BasicDBObject(
            mapAsJavaMap(
              Map("$centerSphere" -> Array(Array(103.7922211, 36.0563889), 1000 / 111.2))
            )))
        )
      )
    ))
  )

  //  { <location field> :
  //    { $near :
  //      { $geometry :
  //      { type : "Point" ,
  //        coordinates : [ <longitude> , <latitude> ] } ,
  //        $maxDistance : <distance in meters>
  //        } } }
  val query2 = new BasicDBObject(
    mapAsJavaMap(Map(
      "loc" -> new BasicDBObject(
        mapAsJavaMap(
          Map("$near" -> new BasicDBObject(
            mapAsJavaMap(Map("$geometry" -> new BasicDBObject(
              mapAsJavaMap(
                Map("type" -> "Point",
                  "coordinates" -> Array(121.4580536, 31.2222222)
                ))),
              "$maxDistance" -> 2000000)))))))))

    val r = mongo.find(query2)

//    while (r.hasNext) {
//      val obj = r.next()
//      println(
//        obj.get("_id"),
//        obj.get("country"),
//        obj.get("city"))
//    }
  println(r.size())
}