抽象工厂模式
定义一个工厂类接口,让工厂子类来创建一系列相关或相互依赖的对象
例如:成产一部手机,需要手机壳、CPU、操作系统三类对象进行组装,其中每类对象都有不同的种类。对每个具体工厂,分别生产一部手机所需要的三个对象。
相比工厂方法模式,抽象工厂模式中的每个具体工厂都生产一套产品
from abc import ABCMeta, abstractmethod
# --- 抽象产品 ---
class PhoneShell(metaclass=ABCMeta):
@abstractmethod
def show_shell(self):
pass
class CPU(metaclass=ABCMeta):
@abstractmethod
def show_cpu(self):
pass
class OS(metaclass=ABCMeta):
@abstractmethod
def show_os(self):
pass
# --- 抽象工厂 ---
class PhoneFactory(metaclass=ABCMeta):
@abstractmethod
def make_shell(self):
pass
@abstractmethod
def make_cpu(self):
pass
@abstractmethod
def make_os(self):
pass
# --- 具体产品 ---
class SmallShell(PhoneShell):
def show_shell(self):
print('普通手机小手机壳')
class BigShell(PhoneShell):
def show_shell(self):
print('普通手机大手机壳')
class AppleShell(PhoneShell):
def show_shell(self):
print('苹果手机壳')
class SnapDragonCPU(CPU):
def show_cpu(self):
print('骁龙CPU')
class MediaTekCPU(CPU):
def show_cpu(self):
print('联发科CPU')
class AppleCPU(CPU):
def show_cpu(self):
print('评估CPU')
class Android(OS):
def show_os(self):
print('Android系统')
class IOS(OS):
def show_os(self):
print('IOS系统')
# --- 具体工厂 ---
class MiFactory(PhoneFactory):
def make_cpu(self):
return SnapDragonCPU()
def make_os(self):
return Android()
def make_shell(self):
return BigShell()
class HuaweiFactory(PhoneFactory):
def make_cpu(self):
return MediaTekCPU()
def make_os(self):
return Android()
def make_shell(self):
return SmallShell()
class IPhoneFactory(PhoneFactory):
def make_cpu(self):
return AppleCPU()
def make_os(self):
return IOS()
def make_shell(self):
return AppleCPU()
# --- 客户端 ---
class Phone(object):
def __init__(self, cpu, os, shell):
self.cpu = cpu
self.os = os
self.shell = shell
def show_info(self):
print('手机信息:')
self.cpu.show_cpu()
self.os.show_os()
self.shell.show_shell()
def make_phone(factory):
cpu = factory.make_cpu()
os = factory.make_os()
shell = factory.make_shell()
return Phone(cpu, os, shell)
p1 = make_phone(MiFactory())
p1.show_info()
优点:
将客户端与类的具体实现相分离
每个工厂创建了一个完整的产品系列,使得易于交换产品系列
有利于产品的一致性(即产品之间的约束关系)
缺点:
难以支持新种类的(抽象)产品
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