Top 10 Design Patterns Every Java Developer Should Know 🚀

Design patterns are proven solutions to common software design problems. They help make code more readable, reusable, maintainable, and scalable. Java developers use design patterns extensively to follow best practices and improve software architecture.

This article covers 10 essential design patterns that every Java developer should know and how to implement them the right way using best practices.

1. Singleton Pattern (Ensuring a Single Instance)

Use Case: Managing database connections, logging, and configuration settings

The Singleton Pattern ensures that only one instance of a class exists and provides a global access point to it.

Best Practice Implementation (Thread-Safe & Secure Singleton)

public class Singleton {

    // Volatile ensures visibility across threads and prevents instruction reordering
    private static volatile Singleton instance;

    // Private constructor prevents direct instantiation
    private Singleton() {
        if (instance != null) {
            throw new RuntimeException("Use getInstance() to create an object");
        }
    }

    // Double-checked locking for thread safety
    public static Singleton getInstance() {
        if (instance == null) {  // First check (No lock)
            synchronized (Singleton.class) {…