Here I am with my another article on design patterns - Builder Design Pattern. A very useful creational design pattern that lets us construct complex objects step by step.

Builder Design Pattern

• The Builder design pattern is designed to provide a flexible solution to various object creation problems in object-oriented programming.
• The Builder design pattern provides a way to separate the construction of a complex object from its representation.
• The Builder pattern constructs a complex object by using simple objects and step by step approach.
• The pattern provides one of the best ways to create a complex object.
• It is one of the Gang of Four design patterns that describe how to solve recurring design problems in object-oriented software.
• This pattern is useful to build different immutable objects using same object building process.

The builder pattern is a design pattern that allows for the step-by-step creation of complex objects using the correct sequence of actions. The construction is controlled by a director object that only needs to know the type of object it is to create.

So the important components of Builder Design Pattern are as below:

• Product — The Class which defines the complex object we are trying to build step by step using simple objects.
• Builder — The abstract class/interface which defines all the steps required to perform to produce the complex Product object. Generally, each step is declared here (abstract) since the implementation comes under the concrete builder class.
• ConcreteBuilder — The Builder class which provides the actual code to build the Product object. We can have number of different ConcreteBuilder classes each one giving a different flavor or way of producing the Product object.
• Director — The class under which supervision builder performs the ordered steps to build the Product object. The Director normally receives the builder to perform the steps in correct order to build the Product object.

The Builder design pattern solves problems like:

• How can a class (the same construction process) create different representations of a complex object?
• How can a class that includes creating a complex object be simplified?

Let’s implements a Car Manufacturing Example using Builder Design Pattern.

#java #tutorial #design pattern #builder