MongoCollection in Spring Boot

In this post, we will learn to use a MongoCollection instance for database operations in the Spring Boot application.

We all know that we have a spring boot data repository for MongoDB which has an interface MongoRepository and a class MongoTemplate that is the best way in Spring Boot for database operations.

Though, Spring Boot provides these options for database operation. Sometimes, we need to use MongoCollection instance in Spring Boot which is a native way of connecting MongoDB database in Java.

Configurations in our application.properties file to connect MongoDB database looks like:

spring.data.mongodb.database=mydatabase
spring.data.mongodb.port=27017
spring.data.mongodb.host=localhost
// other configuration like username/password

Spring Boot automatically provides an instance of MongoDatabaseFactory interface for factories creating MongoDatabase instances.

See the example below to initialize MongoDatabaseFactory.

@Autowired
MongoDatabaseFactory mongoDatabaseFactory;

Now, we can use the mongoDatabaseFactory instance to initialize the MongoCollection instance with following code:

MongoCollection<Document> employeesCollection =  mongoDbFactory.getMongoDatabase().getCollection("employees");

Make sure to import Document from org.bson package like:

import org.bson.Document;

The employeesCollection is an instance of a collection of employees in the database mydatabase (You can see in the properties file to know the database name).

Now, we can use employeesCollection object to do database operations like:

employeeCollection.find();

This will return the iterable object of the Document. Where we can find all the keys as fields and their values available in employees collection.

Similarly, we can use employeeCollection for other operations available in MongoDB.

The main objective of this post is to learn to use MongoCollection in Spring Boot to work in a Native way.

Hence, I will write another post for CRUD operation in MongoDB using Java.