Geospatial Search

To support geospatial queries, MongoDB provides various geospatial indexes as well as geospatial query operators.

Prerequisites

• The example below requires a restaurants collection in the test database. To create and populate the collection, follow the directions in github.

• Include the following import statements:

   import org.mongodb.scala._
   import org.mongodb.scala.model.geojson._
   import org.mongodb.scala.model.Indexes
   import org.mongodb.scala.model.Filters
  

  important

  This guide uses the Observable implicits as covered in the Quick Start Primer.

Connect to a MongoDB Deployment

Connect to a MongoDB deployment and declare and define a MongoDatabase instance.

For example, include the following code to connect to a standalone MongoDB deployment running on localhost on port 27017 and define database to refer to the test database:

val mongoClient: MongoClient = MongoClient()
val database: MongoDatabase = mongoClient.getDatabase("test")

For additional information on connecting to MongoDB, see Connect to MongoDB.

Create the 2dsphere Index

To create a 2dsphere index, use the Indexes.geo2dsphere helper to create a specification for the 2dsphere index and pass to MongoCollection.createIndex() method.

The following example creates a 2dsphere index on the "contact.location" field for the restaurants collection.

// Note: this code example uses a custom implicit helper referenced in the Quick Start Primer
val collection = database.getCollection("restaurants")
collection.createIndex(Indexes.geo2dsphere("contact.location")).printResults()

Query for Locations Near a GeoJSON Point

MongoDB provides various geospatial query operators. To facilitate the creation of geospatial queries filters, the Scala driver provides the Filters class and the org.mongodb.scala.model.geojson package.

The following example returns documents that are at least 1000 meters from and at most 5000 meters from the specified GeoJSON point org.mongodb.scala.model.geojson.Point, sorted from nearest to farthest:

// Note: this code example uses a custom implicit helper referenced in the Quick Start Primer
val refPoint = Point(Position(-73.9667, 40.78))
collection.find(Filters.near("contact.location", refPoint, 5000.0, 1000.0)).printResults()