Java MongoDB : Get collection from database

By mkyong | Updated: March 9, 2013

Viewed: 265 (+3 pv/w)

Tags: mongodb query select

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 the collection name “yourCollection”, then you will see the 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();
    }

  }
}