Table of Contents
Java design patterns provide reusable solutions to common software development problems. They help improve code maintainability, flexibility, and readability. This guide introduces some of the most widely used patterns with practical examples.
Creational Design Patterns
Creational patterns focus on object creation mechanisms, aiming to create objects in a manner suitable to the situation. They help reduce complexity and increase flexibility in code.
Singleton Pattern
The Singleton pattern ensures a class has only one instance and provides a global point of access to it. It is useful for managing shared resources like database connections.
Factory Method Pattern
The Factory Method pattern defines an interface for creating an object but allows subclasses to alter the type of objects that will be created. It promotes loose coupling.
Structural Design Patterns
Structural patterns deal with object composition, helping to organize code and establish relationships between entities efficiently.
Adapter Pattern
The Adapter pattern allows incompatible interfaces to work together by converting the interface of one class into another expected by clients.
Behavioral Design Patterns
Behavioral patterns focus on communication between objects, defining how they interact and distribute responsibilities.
Observer Pattern
The Observer pattern establishes a one-to-many dependency between objects so that when one object changes state, all its dependents are notified automatically.
- Decouples subject and observers
- Supports dynamic subscription
- Useful in event-driven systems