추상 팩토리 패턴

추상 팩토리 패턴(Abstract factory pattern)은 다양한 구성 요소 별로 '객체의 집합'을 생성해야 할 때 유용하다. 이 패턴을 사용하여 상황에 알맞은 객체를 생성할 수 있다.
대표적인 예로, 자바 프로그래밍 언어의 GUI 구성 요소인 AWT/Swing 라이브러리의 룩 앤드 필 변경 기능을 들 수 있다. 메탈, 마이크로소프트 윈도우, 맥 OS 등의 모양으로 변경할 수 있다. 이에 따라 추상 팩토리에 있는 기본 팩토리 객체가 변경된다. 그러면 이후로 생성되는 GUI 객체들은 전부 해당 룩앤필에 따른다.

**구조**

**UML 클래스 및 시퀀스 다이어그램**
추상 팩토리 패턴을 위한 샘플 UML 클래스 및 시퀀스 다이어그램.

**클래스 다이어그램**
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**UML 클래스 다이어그램**
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**Lepus3 차트 ( 범례)**
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**C # 예제**
interface IButton
{
void Paint();
}
interface IGUIFactory
{
IButton CreateButton();
}
class WinFactory : IGUIFactory
{
public IButton CreateButton()
{
return new WinButton();
}
}
class OSXFactory : IGUIFactory
{
public IButton CreateButton()
{
return new OSXButton();
}
}
class WinButton : IButton
{
public void Paint()
{
//Render a button in a Windows style
}
}
class OSXButton : IButton
{
public void Paint()
{
//Render a button in a Mac OS X style
}
}
class Program
{
static void Main()
{
var appearance = Settings.Appearance;
IGUIFactory factory;
switch (appearance)
{
case Appearance.Win:
factory = new WinFactory();
break;
case Appearance.OSX:
factory = new OSXFactory();
break;
default:
throw new System.NotImplementedException();
}
var button = factory.CreateButton();
button.Paint();
}
}

**Golang 예제**
package main
import (
	"fmt"
)
type Button interface {
	Paint()
}
type GUIFactory interface {
	CreateButton() Button
}
type WinFactory struct{}
func (f *WinFactory) CreateButton() Button {
	return new(WinButton)
}
type OSXFactory struct{}
func (f *OSXFactory) CreateButton() Button {
	return new(OSXButton)
}
type LinuxFactory struct{}
func (f *LinuxFactory) CreateButton() Button {
	return new(LinuxButton)
}
type WinButton struct{}
func (b *WinButton) Paint() {
	fmt.Println("WinButton")
}
type OSXButton struct{}
func (b *OSXButton) Paint() {
	fmt.Println("OSXButton")
}
type LinuxButton struct{}
func (b *LinuxButton) Paint() {
	fmt.Println("LinuxButton")
}
func BuildFactory(appearance string) GUIFactory {
	switch appearance {
	case "Window":
		return new(WinFactory)
	case "OSX":
		return new(OSXFactory)
	case "Linux":
		return new(LinuxFactory)
	}
	return nil
}
func main() {
	if factory := BuildFactory("Window"); factory != nil {
		winButton := factory.CreateButton()
		winButton.Paint()
	}
	if factory := BuildFactory("OSX"); factory != nil {
		osxButton := factory.CreateButton()
		osxButton.Paint()
	}
	if factory := BuildFactory("Linux"); factory != nil {
		linuxButton := factory.CreateButton()
		linuxButton.Paint()
	}
}

**Python 예제**
import enum
from abc import 
class Button:
@abstractmethod
def Paint(self):
pass
class MousePointer:
@abstractmethod
def Paint(self):
pass
class GUIFactory:
@abstractmethod
def CreateButton(self):
return Button
@abstractmethod
def CreateMousePointer(self):
return MousePointer
class WinFactory(GUIFactory):
def CreateButton(self):
return WinButton()
def CreateMousePointer(self):
return WinMousePointer()
class OSXFactory(GUIFactory):
def CreateButton(self):
return OSXButton()
def CreateMousePointer(self):
return OSXMousePointer()
class WinMousePointer(MousePointer):
def Paint(self):
print("Render a mousepointer in a Windows style")
class OSXMousePointer(MousePointer):
def Paint(self):
print ("Render a mousepointer in a OSX style")
class WinButton(Button):
def Paint(self):
print ("Render a button in a Windows style")
class OSXButton(Button):
def Paint(self):
print ("Render a button in a Mac OSX style")
class Settings:
@staticmethod
def Default():
return Appearance.WIN
class Appearance(enum.Enum):
WIN = 0
OSX = 1
def main():
apperance = Settings.Default()
if apperance == Appearance.WIN:
factory = WinFactory()
elif apperance == Appearance.OSX:
factory = OSXFactory()
button = factory.CreateButton()
mousePointer = factory.CreateMousePointer()
button.Paint()
mousePointer.Paint()
if __name__ == '__main__':
main()

**PHP 예제**
interface Button
{
public function paint();
}
interface GUIFactory
{
public function createButton(): Button;
}
class WinFactory implements GUIFactory
{
public function createButton(): Button
{
return new WinButton();
}
}
class OSXFactory implements GUIFactory
{
public function createButton(): Button
{
return new OSXButton();
}
}
class WinButton implements Button
{
public function paint()
{
echo "Windows Button";
}
}
class OSXButton implements Button
{
public function paint()
{
echo "OSX Button";
}
}
$appearance = "osx";
$factory = NULL;
switch ($appearance) {
case "win":
$factory = new WinFactory();
break;
case "osx":
$factory = new OSXFactory();
break;
default:
break;
}
if ($factory instanceof GUIFactory) {
$button = $factory->createButton();
$button->paint();
}

**같이 보기**
 팩토리 메서드 패턴- 소프트웨어 디자인 패턴

**각주**
분류:소프트웨어 디자인 패턴