Top 5 Design Patterns in Java Spring Boot: Best Practices and Examples

These are design patterns I often use and absolutely love…

As a seasoned Java backend developer immersed in the world of Spring Boot and Spring Framework for a decade, I’ve come to realize the crucial role that design patterns play in building robust and scalable applications. In this article, we’ll delve into five essential design patterns and explore the best practices for applying them effectively in your Spring Boot projects. Each pattern will be accompanied by a practical example to demonstrate its implementation.

Singleton Pattern

The Singleton pattern ensures that a class has only one instance and provides a global point of access to it. This is particularly useful for managing resources such as database connections or caching objects. Here’s how you can implement it in Spring Boot:

public class DatabaseConnection {
    private static DatabaseConnection instance;

    private DatabaseConnection() {
        // Private constructor to prevent instantiation
    }
    public static synchronized DatabaseConnection getInstance() {
        if (instance == null) {
            instance = new DatabaseConnection();
        }
        return instance;
    }
}

Factory Method Pattern

The Factory Method pattern provides an interface for creating objects in a superclass, allowing subclasses to alter the type of objects that will be created. This is useful for decoupling object creation logic from client code. Let’s see an example in Spring Boot:

public interface PaymentProcessor {
    void processPayment();
}

public class CreditCardProcessor implements PaymentProcessor {
    @Override
    public void processPayment() {
        // Process credit card payment logic
    }
}
public class PayPalProcessor implements PaymentProcessor {
    @Override
    public void processPayment() {
        // Process PayPal payment logic
    }
}
public interface PaymentProcessorFactory {
    PaymentProcessor createPaymentProcessor();
}
@Component
public class PaymentProcessorFactoryImpl implements PaymentProcessorFactory {
    @Override
    public PaymentProcessor createPaymentProcessor() {
        // Logic to determine…