In software engineering, a design pattern is a general reusable solution to a commonly occurring problem in software design. A design pattern is not a finished design that can be transformed directly into code. It is a description or template for how to solve a problem that can be used in many different situations.
Object-oriented design patterns typically show relationships and interactions between classes or objects, without specifying the final application classes or objects that are involved.
The Gang of Four (GoF) patterns are generally considered the foundation for all other patterns. They are categorized in three groups:
1. Creational
2. Structural
3. Behavioral
Creational Patterns
Abstract Factory - Creates an instance of several families of classes
Builder - Separates object construction from its representation
Factory Method - Creates an instance of several derived classes
Prototype - A fully initialized instance to be copied or cloned
Singleton - A class of which only a single instance can exist
Structural Patterns
Adapter - Match interfaces of different classes
Bridge - Separates an object’s interface from its implementation
Composite - A tree structure of simple and composite objects
Decorator - Add responsibilities to objects dynamically
Facade - A single class that represents an entire subsystem
Flyweight - A fine-grained instance used for efficient sharing
Proxy - An object representing another object
Behavioral Patterns
Chain of Resp - A way of passing a request between a chain of objects
Command - Encapsulate a command request as an object
Interpreter - A way to include language elements in a program
Iterator - Sequentially access the elements of a collection
Mediator - Defines simplified communication between classes
Memento - Capture and restore an object's internal state
Observer - A way of notifying change to a number of classes
State - Alter an object's behavior when its state changes
Strategy - Encapsulates an algorithm inside a class
Template Method - Defer the exact steps of an algorithm to a subclass
Visitor - Defines a new operation to a class without change
Links:
Non-Software Examples of Software Design Patterns -
http://www2.ukdw.ac.id/kuliah/info/TR3063/NonSoftwareExamplesOfSoftwareDesignPatterns.pdf
Design Patterns, Pattern Languages, and Frameworks -http://www.cs.wustl.edu/~schmidt/patterns.html
Microsoft Application Architecture Guide 2.0 eBook -http://www.codeplex.com/AppArchGuide/Release/ProjectReleases.aspx?ReleaseId=20586
Design Patterns Sample Code (C++ & Java) - http://www.vincehuston.org/dp/
Microsoft Architecture Journal - http://msdn.microsoft.com/en-us/architecture/bb410935.aspx
Microsoft Architecture Journal Reader (Beta) -http://www.microsoft.com/downloads/details.aspx?FamilyID=dd466bbb-1b7d-438e-9f9a-954ce2058f15&displaylang=en
Microsoft’s Home for Design patterns & practices – http://msdn.microsoft.com/en-us/practices/default.aspx
Inject Some Life into Your Applications: Getting to Know the Unity Application Block - http://msdn.microsoft.com/en-us/library/cc816062.aspx
Design Patterns: Solidify Your C# Application Architecture with Design Patterns – http://msdn.microsoft.com/en-us/magazine/cc301852.aspx
CSharp(C#) Design Patterns(with Sample Code) - http://www.dofactory.com/Patterns/Patterns.aspx
Java Design Patterns - http://www.patterndepot.com/put/8/JavaPatterns.htm
J2EE Patterns Catalog - http://java.sun.com/blueprints/patterns/catalog.html
J2EE Design Patterns - http://www.onjava.com/pub/a/onjava/2002/01/16/patterns.html
Gopalan Suresh Raj's blog - http://gsraj.tripod.com/
