Abstract Factory パターンはまさにこの問題に対応しています。Google GoF Abstract Factory {ご希望の言語}
以下では、具体的なファクトリを使用して「完全な」オブジェクト (enzo、civic) を生成する方法、またはそれらを使用して関連オブジェクト (CarbonFrame + TurboEngine、WeakFrame + WeakEngine) の「ファミリ」を生成する方法に注意してください。最終的には、常にタイプ固有の動作でaccelerated()に応答する Car オブジェクトになります。
using System;
abstract class CarFactory
{
public static CarFactory FactoryFor(string manufacturer){
switch(manufacturer){
case "Ferrari" : return new FerrariFactory();
case "Honda" : return new HondaFactory();
default:
throw new ArgumentException("Unknown car manufacturer. Please bailout industry.");
}
}
public abstract Car createCar();
public abstract Engine createEngine();
public abstract Frame createFrame();
}
class FerrariFactory : CarFactory
{
public override Car createCar()
{
return new Ferrari(createEngine(), createFrame());
}
public override Engine createEngine()
{
return new TurboEngine();
}
public override Frame createFrame()
{
return new CarbonFrame();
}
}
class HondaFactory : CarFactory
{
public override Car createCar()
{
return new Honda(createEngine(), createFrame());
}
public override Engine createEngine()
{
return new WeakEngine();
}
public override Frame createFrame()
{
return new WeakFrame();
}
}
abstract class Car
{
private Engine engine;
private Frame frame;
public Car(Engine engine, Frame frame)
{
this.engine = engine;
this.frame = frame;
}
public void accelerate()
{
engine.setThrottle(1.0f);
frame.respondToSpeed();
}
}
class Ferrari : Car
{
public Ferrari(Engine engine, Frame frame) : base(engine, frame)
{
Console.WriteLine("Setting sticker price to $250K");
}
}
class Honda : Car
{
public Honda(Engine engine, Frame frame) : base(engine, frame)
{
Console.WriteLine("Setting sticker price to $25K");
}
}
class KitCar : Car
{
public KitCar(String name, Engine engine, Frame frame)
: base(engine, frame)
{
Console.WriteLine("Going out in the garage and building myself a " + name);
}
}
abstract class Engine
{
public void setThrottle(float percent)
{
Console.WriteLine("Stomping on accelerator!");
typeSpecificAcceleration();
}
protected abstract void typeSpecificAcceleration();
}
class TurboEngine : Engine
{
protected override void typeSpecificAcceleration()
{
Console.WriteLine("Activating turbo");
Console.WriteLine("Making noise like Barry White gargling wasps");
}
}
class WeakEngine : Engine
{
protected override void typeSpecificAcceleration()
{
Console.WriteLine("Provoking hamster to run faster");
Console.WriteLine("Whining like a dentist's drill");
}
}
abstract class Frame
{
public abstract void respondToSpeed();
}
class CarbonFrame : Frame
{
public override void respondToSpeed()
{
Console.WriteLine("Activating active suspension and extending spoilers");
}
}
class WeakFrame : Frame
{
public override void respondToSpeed()
{
Console.WriteLine("Loosening bolts and vibrating");
}
}
class TestClass
{
public static void Main()
{
CarFactory ferrariFactory = CarFactory.FactoryFor("Ferrari");
Car enzo = ferrariFactory.createCar();
enzo.accelerate();
Console.WriteLine("---");
CarFactory hondaFactory = CarFactory.FactoryFor("Honda");
Car civic = hondaFactory.createCar();
civic.accelerate();
Console.WriteLine("---");
Frame frame = hondaFactory.createFrame();
Engine engine = ferrariFactory.createEngine();
Car kitCar = new KitCar("Shaker", engine, frame);
kitCar.accelerate();
Console.WriteLine("---");
Car kitCar2 = new KitCar("LooksGreatGoesSlow", hondaFactory.createEngine(), ferrariFactory.createFrame());
kitCar2.accelerate();
}
}