UML class structure

The following UML diagram shows all the components of the Builder design pattern:

UML diagram for the Builder design pattern:

  • Builder (AccountBuilder): This is an abstract class or interface for creating the details of an Account object.
  • ConcreteBuilder: This is an implementation to construct and assemble details of the account by implementing the Builder interface.
  • Director: This constructs an object using the Builder interface.
  • Product (Account): This represents the complex object under construction. AccountBuilder builds the account's internal representation and defines the process by which it's assembled.