Run Commands

Not all commands have a specific helper. However you can run any MongoDB command by using the MongoDatabase’s runCommand() method.

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 com.mongodb.reactivestreams.client.MongoClients;
 import com.mongodb.reactivestreams.client.MongoClient;
 import com.mongodb.reactivestreams.client.MongoDatabase;
 import org.bson.Document;
important

This guide uses the Subscriber implementations 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:

MongoClient mongoClient = MongoClients.create();
MongoDatabase database = mongoClient.getDatabase("test");

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

Run buildInfo and collStats Commands

To run a command, construct a Document object that specifies the command and pass it to the runCommand() method.

The following runs the buildInfo command and the collStats command:

database.runCommand(new Document("buildInfo", 1)).subscribe(new PrintDocumentSubscriber());

database.runCommand(new Document("collStats", "restaurants")).subscribe(new PrintDocumentSubscriber());

For a list of available MongoDB commands, see MongoDB commands.

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