Java MongoDB : Get collection from database

In Java, you can use db.getCollection(“your collection name”) to get a single collection to use.

DBCollection collection = db.getCollection("yourCollection");

If you do not know the collection name, use db.getCollectionNames() to get the entire list of collection names from a selected database.

DB db = mongo.getDB("yourdb");
Set<String> collections = db.getCollectionNames();
 
for (String collectionName : collections) {
	System.out.println(collectionName);
}

If “yourdb” contains collection name “yourCollection”, then you will see following result :

system.indexes  //system collection
system.users     //system colection
yourCollection

Full example to get collection from MongoDB, via Java driver.

package com.mkyong.core;
 
import java.net.UnknownHostException;
import java.util.Set;
 
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.Mongo;
import com.mongodb.MongoException;
 
/**
 * Java : Get collection from MongoDB
 * 
 */
public class GetCollectionApp {
	public static void main(String[] args) {
 
		try {
 
			Mongo mongo = new Mongo("localhost", 27017);
			DB db = mongo.getDB("yourdb");
 
			// get list of collections
			Set<String> collections = db.getCollectionNames();
 
			for (String collectionName : collections) {
				System.out.println(collectionName);
			}
 
			// get a single collection
			DBCollection collection = db.getCollection("yourCollection");
			System.out.println(collection.toString());
 
			System.out.println("Done");
 
		} catch (UnknownHostException e) {
			e.printStackTrace();
		} catch (MongoException e) {
			e.printStackTrace();
		}
 
	}
}