Java mongodb example for beginners

Java mongodb example for beginners

I'd be happy to help! However, please note that I'll respond in English as you've requested.

Now, let's dive into a step-by-step Java MongoDB example perfect for beginners!

Prerequisites:

Step-by-Step Example:

org.mongodb
mongo-java-driver
4.3.1

import com.mongodb.MongoClient;
import com.mongodb.MongoCredential;
import com.mongodb.MongoDB;
import com.mongodb.ServerAddress;
public class MongoDBExample {
public static void main(String[] args) {
// Connect to MongoDB
MongoClient mongoClient = new MongoClient(new ServerAddress("localhost", 27017),
MongoCredential.createCredential("your_database_name", "your_database_password").toArray());
// Get a reference to the database
MongoDB db = mongoClient.getDB("your_database_name");
}
}

// Create a new collection (or use an existing one)
MongoDB collection = db.getCollection("mycollection");
// Create a new document
DBObject document = new BasicDBObject();
document.put("name", "John Doe");
document.put("age", 30);
// Insert the document into the collection
collection.insert(document);

// Find all documents in the collection
BasicDBObject query = new BasicDBObject();
List results = collection.find(query).toArray();
// Print the results
for (BasicDBObject result : results) {
System.out.println(result);
}

// Close the MongoDB connection
mongoClient.close();

Putting it all together:

Here's the complete code snippet for your reference:

import com.mongodb.BasicDBObject;
import com.mongodb.MongoClient;
import com.mongodb.MongoCredential;
import com.mongodb.MongoDB;
import com.mongodb.ServerAddress;
public class MongoDBExample {
public static void main(String[] args) {
// Connect to MongoDB
MongoClient mongoClient = new MongoClient(new ServerAddress("localhost", 27017),
MongoCredential.createCredential("your_database_name", "your_database_password").toArray());
// Get a reference to the database
MongoDB db = mongoClient.getDB("your_database_name");
// Create and insert documents
MongoDB collection = db.getCollection("mycollection");
BasicDBObject document = new BasicDBObject();
document.put("name", "John Doe");
document.put("age", 30);
collection.insert(document);
// Query and retrieve documents
BasicDBObject query = new BasicDBObject();
List results = collection.find(query).toArray();
// Print the results
for (BasicDBObject result : results) {
System.out.println(result);
}
// Close the MongoDB connection
mongoClient.close();
}
}

This example demonstrates basic operations in MongoDB using Java:

Feel free to modify the code as needed for your specific use case. Happy coding!

Java mongodb example github

I'm glad you asked!

If you're interested in using MongoDB with Java, there are several examples and tutorials available on GitHub that can help you get started.

Here are a few popular ones:

Example code:

// Connecting to the database
MongoClient client = new MongoClient("localhost", 27017);
// Getting a reference to the "mydatabase" database
DB db = client.getDB("mydatabase");
// Creating a new collection
DBCollection collection = db.getCollection("mycollection");
// Inserting data into the collection
DBObject document = new BasicDBObject("name", "John")
.append("age", 30)
.append("city", "New York");
collection.insert(document);

Example code:

// Creating a new MongoDB instance
MongoDB mongo = new MongoDB("localhost", 27017);
// Getting a reference to the "mydatabase" database
Database database = mongo.getDatabase("mydatabase");
// Creating a new collection
Collection collection = database.getCollection("mycollection");
// Inserting data into the collection
Document document = new Document("name", "John")
.append("age", 30)
.append("city", "New York");
collection.insertOne(document);

Example code:

// Inserting data
public void insertDocument(String collectionName, String name, int age, String city) {
MongoClient client = new MongoClient("localhost", 27017);
DB db = client.getDB("mydatabase");
DBCollection collection = db.getCollection(collectionName);
BasicDBObject document = new BasicDBObject()
.append("name", name)
.append("age", age)
.append("city", city);
collection.insert(document);
}
// Reading data
public List readDocuments(String collectionName, String query) {
MongoClient client = new MongoClient("localhost", 27017);
DB db = client.getDB("mydatabase");
DBCollection collection = db.getCollection(collectionName);
BasicDBObject queryObject = new BasicDBObject();
queryObject.put(query, "John");
List documents = collection.find(queryObject).toList();
return documents;
}
// Updating data
public void updateDocument(String collectionName, String name, int newAge) {
MongoClient client = new MongoClient("localhost", 27017);
DB db = client.getDB("mydatabase");
DBCollection collection = db.getCollection(collectionName);
BasicDBObject queryObject = new BasicDBObject();
queryObject.put("name", name);
BasicDBObject updateObject = new BasicDBObject();
updateObject.put("age", newAge);
collection.update(queryObject, updateObject);
}
// Deleting data
public void deleteDocument(String collectionName, String name) {
MongoClient client = new MongoClient("localhost", 27017);
DB db = client.getDB("mydatabase");
DBCollection collection = db.getCollection(collectionName);
BasicDBObject queryObject = new BasicDBObject();
queryObject.put("name", name);
collection.remove(queryObject);
}

These examples should give you a good starting point for using MongoDB with Java. Happy coding!