Create a MongoClient
Overview
To connect to a MongoDB deployment, you need two things:
A connection URI, also known as a connection string, which tells the Kotlin Sync driver which MongoDB deployment to connect to.
A MongoClient object, which creates the connection to and performs operations on the MongoDB deployment.
You can also use MongoClientSettings to customize the way the Kotlin Sync driver behaves
while connected to MongoDB.
This guide shows you how to create a connection string and use a MongoClient object
to connect to MongoDB.
Connection URI
A standard connection string includes the following components:
Component | Description |
|---|---|
mongodb:// | Required. A prefix that identifies this as a string in the
standard connection format. |
username:password | Optional. Authentication credentials. If you include these, the client
authenticates the user against the database specified in authSource. |
host[:port] | Required. The host and optional port number where MongoDB is running. If you don't
include the port number, the driver uses the default port, 27017. |
/defaultauthdb | Optional. The authentication database to use if the
connection string includes username:password@
authentication credentials but not the authSource option. If you don't include
this component, the client authenticates the user against the admin database. |
?<options> | Optional. A query string that specifies connection-specific
options as <name>=<value> pairs. See
Specify Connection Options for a full description of
these options. |
For more information about creating a connection string, see Connection Strings in the MongoDB Server documentation.
Atlas Connection Example
To connect to a MongoDB deployment on Atlas, you must first create a client.
You can pass a connection URI as a string to the MongoClient.create() method
to connect to a MongoDB instance:
// Replace the placeholder with your Atlas connection string val uri = "<connection string>" // Create a new client and connect to the server val mongoClient = MongoClient.create(uri) val database = mongoClient.getDatabase("sample_mflix")
You can also create a client with your desired configurations by passing a
MongoClientSettings object to the MongoClient.create() method.
To instantiate a MongoClientSettings object, use the builder method to
specify your connection string, using the applyConnectionString() method,
and any other client options. Once you have your desired configuration,
call the build() method.
You can set the Stable API version client option to avoid breaking changes when you upgrade to a new server version. To learn more about the Stable API feature, see the Stable API page.
The following code shows how you can specify the connection string and the Stable API client option when connecting to a MongoDB deployment on Atlas and verify that the connection is successful:
// start-connect-to-atlas-w-uri // Replace the placeholder with your Atlas connection string val uri = "<connection string>" val mongoClient1 = MongoClient.create(uri) // end-connect-to-atlas-w-uri // Construct a ServerApi instance using the ServerApi.builder() method val serverApi = ServerApi.builder() .version(ServerApiVersion.V1) .build() val settings = MongoClientSettings.builder() .applyConnectionString(ConnectionString(uri)) .serverApi(serverApi) .build() // Create a new client and connect to the server val mongoClient = MongoClient.create(settings) val database = mongoClient.getDatabase("sample_mflix") try { // Send a ping to confirm a successful connection val command = Document("ping", BsonInt64(1)) val commandResult = database.runCommand(command) println("Pinged your deployment. You successfully connected to MongoDB!") } catch (me: MongoException) { System.err.println(me) }
API Documentation
For more information about creating a MongoClient object with the
Kotlin Sync driver, see the following API documentation: