Design Patterns
Design Patterns
Design Patterns
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
Structure<br />
Product<br />
ConcreteProduct<br />
<br />
61<br />
Creator<br />
FactoryMethod()<br />
AnOperation()<br />
ConcreteCreator<br />
FactoryMethod()<br />
AnOperation()<br />
APPLICATION OF THE FACTORY METHOD PATTERN<br />
Files<br />
Open()<br />
Close()<br />
Save()<br />
<br />
Text−File OpenOffice<br />
63<br />
Application<br />
CreateFiles()<br />
NewFiles()<br />
OpenFiles()<br />
CreateFiles()<br />
Participants<br />
• Product (Files)<br />
– defines the interface of objects the FactoryMethod() creates<br />
• ConcreteProduct (Text-File)<br />
– implements the Product interface<br />
• Creator (Application)<br />
– declares the FactoryMethod(), which returns an object of type<br />
Product<br />
• ConcreteCreator (Open Office)<br />
– overrides the FactoryMethod() to return an instance of a<br />
ConcreteProduct<br />
Related <strong>Patterns</strong> Abstract Factory, Template Method, Prototypes<br />
WHAT HAVE WE LEARNT?<br />
➠ <strong>Design</strong> patterns are object oriented patterns at detailed design level.<br />
➠ They are closer to implementation than architectural styles.<br />
➠ According to the GoF classification, there are behavioral, creational and<br />
structural patterns.<br />
➠ <strong>Design</strong> patterns support achieving desirable properties in implementing<br />
62<br />
object-oriented software, e.g. independent modification of parts, limitation<br />
of communication paths etc.<br />
64
Change language