How to implement design patterns in Java?
Design Patterns help in building maintainable and reusable code.
Here are the 23 Design Patterns explained by the Gang of Four in their book “Design Patterns – Elements of Reusable Object-Oriented Software”
I have also published a book on this . Please check out:
All the posts have been created by referring to the original book and they follow the below format:
-A Use Case which the design pattern solves
-Explanation of the Design Pattern with code
-What the Gang of Four say about the pattern
-Link to Github URL with the entire code describing the pattern.
Creational :
Deals with how to create objects.
Singleton – Create a single instance of an object.
Prototype – Use an existing object by cloning it.
Factory Method – Delegate creation of an object to another object.
Abstract Factory – Delegate creation of a group of related objects to another object.
Builder – Delegate creation of a complex object to another object.
Structural:
Deals with how to structure objects.
Adapter – Make two incompatible interfaces work together.
Bridge – Separate abstraction and implementation.
Composite – Treat part-whole hierarchy the same way.
Decorator – Add responsibilities to an object dynamically.
Facade – Provide a single interface for a group of related operations.
Flyweight – Reuse objects than creating new ones.
Proxy – Protect access to an object.
Behavioral
Deals with how to communicate between objects.
Chain of Responsibility – Allow different objects to carry out a responsibility.
Command – Encapsulate requests as separate objects.
Mediator – Act as a broker for communication between objects.
Template – Provide basic template of an algorithm to implement.
Strategy – Encapsulate different algorithms using separate objects which can be chosen at run time.
State – Encapsulate state specific behavior in a separate object.
Observer – Intimate group of objects when a change occurs.
Memento – Allow to revert an object’s state.
Iterator – Provide a generic way to iterate through collection of objects.
Interpreter – Represent a grammar using an object.
Visitor – Add new responsibilities to an object without changing its existing behavior.
The code samples for all the above patterns structured under respective folders are present here :
https://github.com/vijaysrj/designPatternsGoF
