part2 adapter pattern

8/14/2019 Part2 Adapter Pattern

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Structural patternsIn Software Engineering, Structural DesignPatterns are Design Patterns that ease thedesign by identifying a simple way to realizerelationships between entities.AdapterMatch interfaces of different classesBridgeSeparates an objects interface fromits implementationComposite

A tree structure of simple and composite objectsDecoratorAdd responsibilities to objects dynamicallyFacadeA single class that represents an entire subsystemProxy

An object representing another object
http://sourcemaking.com/design_patterns/adapterhttp://sourcemaking.com/design_patterns/bridgehttp://sourcemaking.com/design_patterns/compositehttp://sourcemaking.com/design_patterns/decoratorhttp://sourcemaking.com/design_patterns/facadehttp://sourcemaking.com/design_patterns/proxyhttp://sourcemaking.com/design_patterns/proxyhttp://sourcemaking.com/design_patterns/facadehttp://sourcemaking.com/design_patterns/decoratorhttp://sourcemaking.com/design_patterns/compositehttp://sourcemaking.com/design_patterns/bridgehttp://sourcemaking.com/design_patterns/adapter


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Creational patternIn software engineering, creational designpatterns are design patterns that deal withobject creation mechanisms, trying to createobjects in a manner suitable to the situation. The

basic form of object creation could result indesign problems or added complexity to thedesign. Creational design patterns solve thisproblem by somehow controlling thisobject creation


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Creational pattern

Abstract FactoryCreates an instance of several families of classesBuilderSeparates object construction from its representation

Factory MethodCreates an instance of several derived classesObject PoolAvoid expensive acquisition and release of resources byrecycling objects that are no longer in use

PrototypeA fully initialized instance to be copied or clonedSingletonA class of which only a single instance can exist
http://sourcemaking.com/design_patterns/abstract_factoryhttp://sourcemaking.com/design_patterns/builderhttp://sourcemaking.com/design_patterns/factory_methodhttp://sourcemaking.com/design_patterns/object_poolhttp://sourcemaking.com/design_patterns/prototypehttp://sourcemaking.com/design_patterns/singletonhttp://sourcemaking.com/design_patterns/singletonhttp://sourcemaking.com/design_patterns/prototypehttp://sourcemaking.com/design_patterns/object_poolhttp://sourcemaking.com/design_patterns/factory_methodhttp://sourcemaking.com/design_patterns/builderhttp://sourcemaking.com/design_patterns/abstract_factory


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Adapter pattern -

IntentConvert the interface of a class into anotherinterface clients expect.

Adapter lets classes work together that couldnt

otherwise because of incompatible interfaces.

Wrap an existing class with a new interface.

Match an old component to a new system


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Adapter pattern -

ProblemAn off the shelf component offerscompelling functionality that you would

like to reuse, but its view of the worldis not compatible with the philosophy andarchitecture of the system currentlybeing developed.


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Adapter pattern -

MotivationWhen we want to reuse classes in an applicationthat expects classes with a different interface, we donot want (and often cannot) to change the reusableclasses to suit our application.

Adapter is about creating an intermediaryabstraction that translates, or maps, the oldcomponent to the new system. Clients call methodson the Adapter object which redirects them into callsto the legacy component. This strategy can beimplemented either with inheritance orwith aggregation.

Adapter functions as a wrapper or modifier of an

existing class. It provides a different or translated


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Adapter pattern


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Adapter pattern


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How the client uses

the Adapter patternThe clients make a request to the adapter bycalling a method on it using the target

interface .

The adapter translates that request into oneor more calls on the adaptee using theadaptee Interface.

The client receives the results of the call andnever knows there is an adapter doing the

Translation .


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Adapter pattern -

Structure


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Adapter pattern -

Structure


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Software Design (OODPatterns(

Participants of theAdapter Pattern

Target: Defines the application-specificinterface that clients use.

Client: Collaborates with objects

conforming to the target interface.

Adaptee: Defines an existing interfacethat needs adapting.

Adapter: Adapts the interface of theadaptee to the target interface.


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Example - AdapterPattern

Ad ti


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Adapting anEnumeration to an

Iterator

part2 adapter pattern

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