Thursday, June 28, 2012

MongoDB with Java

NoSQL databases due to their scalability are becoming increasingly popular. When used appropriately NoSQL databases can offer real benefits. MongoDB is such a highly scalable opensource NoSQL database written in C++.

1. Installing MongoDB

Without much of a trouble you can install MongoDB using the instructions given in the official MongoDB site, according to whatever the OS you are using.

2. Starting the MongoDB server

This is quite simple. Run the mongod.exe file inside bin folder(I am using windows OS here) to start the MongoDB server.

By default the server will start on port 27017 and the data will be stored at /data/db directory which you'll have to create during the installing process.

3. Starting MongoDB shell

You can start the MongoBD shell by running the mongo.exe file.

4. Creating a database with MongoDB

To create a database named "company" using MongoDB type the following on MongoDB shell
 use company 
Mind that MangoDB will not create a database until you save something inside it.

Use following command to view the available databases and that will show you that "company" database hasn't been created yet.
 show dbs; 
5. Saving data in MongoDB

Use following commands to save employee data to a collection called employees
employee = {name : "A", no : 1} 
To view the data inside the collection use following command,
Do it with Java :)

Following is a simple Java code which is doing the same thing we did above. You can get the mongo-java driver from here.

Just go through the code, it's very simple, hopefully you'll get the idea.


import com.mongodb.BasicDBObject;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBCursor;
import com.mongodb.Mongo;
import com.mongodb.MongoException;

public class MongoDBClient {

 public static void main(String[] args) {

  try {

   Mongo mongo = new Mongo("localhost", 27017);

   DB db = mongo.getDB("company");

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

   BasicDBObject employee = new BasicDBObject();
   employee.put("name", "Hannah");
   employee.put("no", 2);


   BasicDBObject searchEmployee = new BasicDBObject();
   searchEmployee.put("no", 2);

   DBCursor cursor = collection.find(searchEmployee);

   while (cursor.hasNext()) {

   System.out.println("The Search Query has Executed!");

  } catch (UnknownHostException e) {
  } catch (MongoException e) {


{ "_id" : { "$oid" : "4fec74dc907cbe9445fd2d70"} , "name" : "Hannah" , "no" : 2}
The Search Query has Executed! 


  1. Good post. Check this out too You might like this. Let me know what you think of it.

    1. Thanks a lot Partha... The link is really good, thanks a lot for sharing :)

  2. I suggest that people interested in using MongoDb with Java check out Morphia; it makes a lot of interactions really simple.

  3. Small but very helpful tutorial.

    Thanks Pavithra.

  4. Hi Pavithra,

    I am a MongoDB-Java enthusiast too...
    I've worked with MongoDB using Spring Data.

    If interested you can visit my developer web site with showcase several MongoDB applications. The link is

    I am curious about morphia, which I just learned about it.

    I think I am going to try it soon.

    Thank you

    1. Hi JD,

      Thanks a lot for sharing your blog here, keep up the good work... Good luck with morphia and hope you'd come up with posts about that too :)