13 Design Patterns

Object Oriented design must be

• specific to the problem, and
• general to adress future problems and requirements

Design Patterns¶

Descriptions of communicating objects and classes, that are customized to solve a general design problem, in a particular context.

allows

• re-usability of design
• faster production of projects
• more accessible
• easier documentation and maintenance

Parts¶

1. Pattern Name
2. Problem
3. Solution
4. Context
5. Class Diagram

Types of Patterns¶

1. Creational Patterns deal with object creation
2. Singleton Single object of a class is created, and all other objects can access it globally
3. Structural Patterns deal with relationship between entities
4. Composite when you put components inside containers eg: JPanel
5. Decorator something that surrounds component eg: scroll bars
6. Adapter Pattern a middle interface ‘adapts’ main interface based on the requirement
7. Proxy Pattern a class acts a proxy to access another class, to keep that hidden
8. Behavioural Patterns communication between objects
9. Iterator access the elements of an aggregate object sequentially without exposing its underlying implementation
10. Observer eg: ActionListener

Comments