Intent
Separate the construction of a complex object from its representation so that the same construction process can create different representations.
Where to use & benefits
- Make a complex object by specifying only its type and content. The built object is shielded from the details of its construction.
- Want to decouple the process of building a complex object from the parts that make up the object.
- Isolate code for construction and representation.
Structure
Participants
Builder (IAppletGUIBuilder)
specifies an abstract interface for creating parts of a Product object.
ConcreteBuilder (ButtonBuilder, ListBuilder)
constructs and assembles parts of the product by implementing the Builder interface.
Director (MainApplet)
constructs an object using the Builder interface.
Product (java.awt.Button, java.awt.List, java.awt.event.ActionListner)
represents the complex object under construction. ConcreteBuilder builds the product's internal representation and defines the process by which it's assembled.
Example
In the demonstration application, MainApplet class uses ButtonBuilder and ListBuilder classes to create and initialize the button and list components in the applet UI.
Class Diagram
