Design patterns represent the best practices used by experienced object-oriented software developers. Design patterns are solutions to general java design patterns pdf that software developers faced during software development.
These solutions were obtained by trial and error by numerous software developers over quite a substantial period of time. This tutorial will take you through step by step approach and examples using Java while learning Design Pattern concepts. This reference has been prepared for the experienced developers to provide best solutions to certain problems faced during software development and for un-experienced developers to learn software design in an easy and faster way.
Before you start proceeding with this tutorial, I’m making an assumption that you are already aware about basic java programming concepts. If you are not well aware of these concepts then I will suggest to go through our short tutorial on Java Programming. In State pattern a class behavior changes based on its state. This type of design pattern comes under behavior pattern.
In State pattern, we create objects which represent various states and a context object whose behavior varies as its state object changes. We are going to create a State interface defining an action and concrete state classes implementing the State interface. Context is a class which carries a State.
Create concrete classes implementing the same interface. Use the Context to see change in behaviour when State changes.
A design pattern isn’t 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.
Design patterns can speed up the development process by providing tested, proven development paradigms. Effective software design requires considering issues that may not become visible until later in the implementation.