Java MongoDB Read Document Example

🎓 Top 15 Udemy Courses (80-90% Discount): My Udemy Courses - Ramesh Fadatare — All my Udemy courses are real-time and project oriented courses.

▶️ Subscribe to My YouTube Channel (178K+ subscribers): Java Guides on YouTube

▶️ For AI, ChatGPT, Web, Tech, and Generative AI, subscribe to another channel: Ramesh Fadatare on YouTube

This tutorial shows how to read documents from a collection in MongoDB using a Java program.

MongoDB is a cross-platform, document-oriented database that provides, high performance, high availability, and easy scalability. MongoDB works on the concept of collection and document.

Learn MongoDB with Java at https://www.javaguides.net/p/java-mongodb-tutorial.html

Tools and Technologies Used

• Java (JDK) 10
• Maven 3.5+
• Eclipse Neon
• MongoDB 3.12.0

Installing MongoDB

Use the following article to install MongoDB on Windows 10.

>> Install MongoDB in Windows 10 - Zip Package

Make sure that you have installed MongoDB and started MongoDB server on default port 27017.

Database Setup

In the previous tutorial, we have created MongoDB database, collection and inserts few documents into a collection.

Java MongoDB Driver

We use the following Maven declaration to include the MongoDB Java Driver in our maven project.

<!-- https://mvnrepository.com/artifact/org.mongodb/mongo-java-driver -->
<dependency>
 <groupId>org.mongodb</groupId>
 <artifactId>mongo-java-driver</artifactId>
 <version>3.12.0</version>
</dependency>

Note that it is an all-in-one JAR, which embeds the core driver and BSON. BSON, short for Bin­ary JSON, is a bin­ary-en­coded seri­al­iz­a­tion of JSON-like doc­u­ments.

Java MongoDB Read Document Example - find() Method

In this example, we iterate over all data of the "users" collection and print to the console.

package net.javaguides.mongodb.document;

import com.mongodb.client.MongoClients;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoCursor;
import org.bson.Document;

import java.util.ArrayList;

/**
 * MongoDB Read Documents Example
 * @author Ramesh Fadatare
 *
 */

public class MongoReadAll {

    public static void main(String[] args) {

        try (var mongoClient = MongoClients.create("mongodb://localhost:27017")) {

            var database = mongoClient.getDatabase("javaguides");

            MongoCollection < Document > collection = database.getCollection("users");

            try (MongoCursor < Document > cur = collection.find().iterator()) {

                while (cur.hasNext()) {

                    var doc = cur.next();
                    var users = new ArrayList < > (doc.values());

                    System.out.printf("%s: %s%n", users.get(1), users.get(2));
                }
            }
        }
    }
}

Output:

Tony: Stark
Tom: Cruise
Amir: Khan
Umesh: Fadatare
Ramesh: Pawar

We retrieve the "users" collection with the getCollection() method:

MongoCollection<Document> collection = database.getCollection("users");

We iterate through the documents of the collection. The find() method finds all documents in the collection:

try (MongoCursor<Document> cur = collection.find().iterator()) {

    while (cur.hasNext()) {

        var doc = cur.next();
        var cars = new ArrayList<>(doc.values());

        System.out.printf("%s: %s%n", cars.get(1), cars.get(2));
    }
}

Java MongoDB Tutorials

All Java MongoDB tutorials at https://www.javaguides.net/p/java-mongodb-tutorial.html

My Top and Bestseller Udemy Courses. The sale is going on with a 70 - 80% discount. The discount coupon has been added to each course below:

Build REST APIs with Spring Boot 4, Spring Security 7, and JWT

🆕 High-Demand 80–90% OFF

[NEW] Learn Apache Maven with IntelliJ IDEA and Java 25

🆕 High-Demand 80–90% OFF

ChatGPT + Generative AI + Prompt Engineering for Beginners

🚀 Trending Now 80–90% OFF

Spring 7 and Spring Boot 4 for Beginners (Includes 8 Projects)

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Building Real-Time REST APIs with Spring Boot - Blog App

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Building Microservices with Spring Boot and Spring Cloud

🌟 Top Rated 80–90% OFF
Available in Udemy for Business

Java Full-Stack Developer Course with Spring Boot and React JS

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Build 5 Spring Boot Projects with Java: Line-by-Line Coding

🌟 Top Rated 80–90% OFF

Testing Spring Boot Application with JUnit and Mockito

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Spring Boot Thymeleaf Real-Time Web Application - Blog App

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Master Spring Data JPA with Hibernate

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Spring Boot + Apache Kafka Course - The Practical Guide

🎓 Student Favorite 80–90% OFF
Available in Udemy for Business

Java Testing: Mastering JUnit 5 Framework

🆕 New 80–90% OFF

Reactive Programming in Java: Spring WebFlux and Testing

🌟 Top Rated 80–90% OFF

Spring Boot + RabbitMQ Course - The Practical Guide

🌟 Top Rated 80–90% OFF
Available in Udemy for Business

Functional Programming in Java (Includes Java Collections)

🎓 Student Favorite 80–90% OFF

ChatGPT for Java Developers: Boost Your Productivity with AI

🚀 Trending Now 80–90% OFF