Design Patterns

• From a list, select the most appropriate design pattern for a given scenario. Patterns will be limited to those documented in Gamma et al. and named using the names given in that book.
• State the benefits of using design patterns.
• State the name of a design pattern (for example, Gamma) given the UML diagram and/or a brief description of the pattern's functionality.
• Select from a list benefits of a specified design pattern (for example, Gamma).
• Identify the design pattern associated with a specified J2EE feature

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Design Patterns(23)
Benefits: Proven solutions, promote reusability, Expressive.
GOF patterns Creation

• Abstract Factory - Allows a client to create families of objects without knowing their concrete classes.
  
• Builder
  
• Factory Method - Subclasses decide which concrete classess to create.
  
• Prototype
• Singleton - Ensures one and only object is created.
  

Behavioural

• Chain of Responsiblity
• Command - Encapsulates a request as an object.
  
• Interpreter
• Iterator
  
• Mediator
• Memento
• Observer - Allows objects to be notified when state changes.
  
• State - Encapsulate state based behaviour and use delegation to switch between behaviour.
  
• Strategy - Encapsulates interchangeable behaviour and used delegation to decide which ones to use.
  
• Template Method - Subclasses decide how to implement steps in an algorithm.
  
• Visitor

Structural

• Adapter - Wraps an object and provides an interface to it.
  
• Bridge
• Composite - Client treats collection of objects and individual objects uniformly.
  
• Decorator - Wraps an object to provide new behaviour.
  
• Facade
• Flyweight
• Proxy - Wraps an object to control access to it.
  

Feature	Pattern
EJB Home	Factory Abstract Factory
EJB Remote	Proxy Facade Decorator
Session beans that model workflow	Facade
EJB instance pooling	Flyweight
Value object	Memento
JDBC Resultset	Iterator
JDBC, JMS, JCA, or any bridging technology	Bridge
ServletContext	Singleton
Servlet filters	Chain of Responsibility Decorator
JMS	Observer Mediator

Need to know all patterns, able to differential between the similiar and identify them from givem UML diagrams.
Books used HeadFirstPatterns/ Developer works/ MarkCade's SCEA.