举例讲解Python设计模式编程中对抽象工厂模式的运用

抽象工厂模式：提供一个创建一系列相关或相互依赖对象的接口，而无需指定它们具体的类。
优点：易于交换“产品系列”，只要更改相应的工厂即可。
缺点：建立产品的时候很繁琐，需要增加和修改很多东西。

优化1：为了避免客户端有过多的逻辑判断，可以封装出一个简单工厂类来生成产品类。
优化2：为了减少简单工厂类里面的逻辑判断，可以采用“反射”机制，直接根据外部的配置文件读取出需要使用产品类的信息。

#encoding=utf-8 
# 
#by panda 
#抽象工厂模式 
 
def printInfo(info): 
  print unicode(info, 'utf-8').encode('gbk') 
   
#抽象产品A：user表 
class IUser(): 
  def Insert(self): 
    pass 
  def GetUser(self): 
    pass 
 
#sqlserver实现的User 
class SqlserverUser(IUser): 
  def Insert(self): 
    printInfo("在SQL Server中给User表增加一条记录") 
  def GetUser(self): 
    printInfo("在SQL Server中得到User表的一条记录") 
 
#Access实现的User 
class AccessUser(IUser): 
  def Insert(self): 
    printInfo("在Access中给User表增加一条记录") 
  def GetUser(self): 
    printInfo("在Access中得到User表一条记录") 
 
 
#抽象产品B：部门表 
class IDepartment(): 
  def Insert(self): 
    pass 
  def GetUser(self): 
    pass 
 
#sqlserver实现的Department 
class SqlserverDepartment(IUser): 
  def Insert(self): 
    printInfo("在SQL Server中给Department表增加一条记录") 
  def GetUser(self): 
    printInfo("在SQL Server中得到Department表的一条记录") 
 
#Access实现的Department 
class AccessDepartment(IUser): 
  def Insert(self): 
    printInfo("在Access中给Department表增加一条记录") 
  def GetUser(self): 
    printInfo("在Access中得到Department表一条记录") 
 
 
#抽象工厂 
class IFactory(): 
  def CreateUser(self): 
    pass 
  def CreateDepartment(self): 
    pass   
 
#sql server工厂 
class SqlServerFactory(IFactory): 
  def CreateUser(self): 
    return SqlserverUser() 
  def CreateDepartment(self): 
    return SqlserverDepartment() 
 
#access工厂 
class AccessFactory(IFactory): 
  def CreateUser(self): 
    return AccessUser() 
  def CreateDepartment(self): 
    return AccessDepartment() 
   
#优化一：采用一个简单工厂类，封装逻辑判断操作 
class DataAccess(): 
#  db = "Sqlserver" 
  db = "Access" 
  @staticmethod 
  def CreateUser(): 
    if (DataAccess.db == "Sqlserver"): 
      return SqlserverUser() 
    elif(DataAccess.db == "Access"): 
      return AccessUser() 
  @staticmethod 
  def CreateDepartment(): 
    if (DataAccess.db == "Sqlserver"): 
      return SqlserverDepartment() 
    elif(DataAccess.db == "Access"): 
      return AccessDepartment() 
     
#优化二：采用反射机制，避免使用太多判断 
##以下信息可以从配置文件中获取 
DBType = 'Sqlserver' #'Access' 
DBTab_User = 'User' 
DBTab_Department = 'Department' 
 
class DataAccessPro(): 
#  db = "Sqlserver" 
  db = "Access" 
  @staticmethod 
  def CreateUser(): 
    funName = DBType + DBTab_User 
    return eval(funName)() #eval 将其中的字符串转化为python表达式 
  @staticmethod 
  def CreateDepartment(): 
    funName = DBType + DBTab_Department 
    return eval(funName)() 
     
def clientUI(): 
  printInfo("\n--------抽象工厂方法--------") 
  factory = SqlServerFactory() 
  iu = factory.CreateUser() 
  iu.Insert() 
  iu.GetUser() 
  id = factory.CreateDepartment() 
  id.Insert() 
  id.GetUser() 
   
  printInfo("\n--抽象工厂方法+简单工厂方法--") 
  iu = DataAccess.CreateUser() 
  iu.Insert() 
  iu.GetUser() 
  id = DataAccess.CreateDepartment() 
  id.Insert() 
  id.GetUser() 
   
  printInfo("\n-抽象工厂方法+简单工厂方法+反射-") 
  iu = DataAccessPro.CreateUser() 
  iu.Insert() 
  iu.GetUser() 
  id = DataAccessPro.CreateDepartment() 
  id.Insert() 
  id.GetUser()   
  return 
 
 
if __name__ == '__main__': 
  clientUI(); 

类图：

工厂模式和抽象工厂模式的区别：工厂模式是在派生类中定义一个工厂的抽象接口，然后基类负责创建具体对象；抽象工厂模式是维护一个产品家族，由基类定义产品被生产的方法，客户根据派生类的接口进行开发。

实例：人民群众喜闻乐见的披萨店例子这里又可以搬出来了，这次我们根据抽象工厂模式的特点，用不同原材料制作不同口味的披萨，创建不同原材料的工厂，不同实体店做出口味不同的披萨。创建一个产品家族（Dough、Sauce、Cheese和Clam）的抽象类型（PizzaIngredientFactory），这个类型的子类（NYPizzaIngredientFactory和ChicagoPizzaIngredientFactory）定义了产品被产生的方法。
代码：

#!/usr/bin/python
# -*- coding:utf-8 -*-
import sys
reload(sys)
sys.setdefaultencoding('utf-8')
 
'''
披萨
'''
class Pizza:
  name = ""
  dough = None
  sauce = None
  cheese = None
  clam = None
 
  def prepare(self):
    pass
 
  def bake(self):
    print "烘烤25分钟在350。".decode('utf-8')
 
  def cut(self):
    print "切割成对角线切片。".decode('utf-8')
 
  def box(self):
    print "放在官方的盒子中。".decode('utf-8')
 
  def get_name(self):
    return self.name
 
  def set_name(self, name):
    self.name = name
 
  def to_string(self):
    string = "%s:\n" % self.name
    string += "  面团: %s\n" % self.dough.to_string() if self.dough else ""
    string += "  酱汁: %s\n" % self.sauce.to_string() if self.sauce else ""
    string += "  奶酪: %s\n" % self.cheese.to_string() if self.cheese else ""
    string += "  文蛤: %s\n" % self.clam.to_string() if self.clam else ""
    return string
 
'''
什么类别的披萨
'''
class CheesePizza(Pizza):
  def __init__(self, ingredient_factory):
    self.ingredient_factory = ingredient_factory
 
  def prepare(self):
    print "准备: %s" % self.name
    self.dough = self.ingredient_factory.create_dough()
    self.sauce = self.ingredient_factory.create_sauce()
    self.cheese = self.ingredient_factory.create_cheese()
 
 
class ClamPizza(Pizza):
  def __init__(self, ingredient_factory):
    self.ingredient_factory = ingredient_factory
 
  def prepare(self):
    print "准备: %s" % self.name
    self.dough = self.ingredient_factory.create_dough()
    self.sauce = self.ingredient_factory.create_sauce()
    self.clam = self.ingredient_factory.create_clam()
 
'''
披萨店
'''
class PizzaStore:
  def order_pizza(self, pizza_type):
    self.pizza = self.create_pizza(pizza_type)
    self.pizza.prepare()
    self.pizza.bake()
    self.pizza.cut()
    self.pizza.box()
    return self.pizza
 
  def create_pizza(self, pizza_type):
    pass
 
'''
纽约披萨实体店1
'''
class NYPizzaStore(PizzaStore):
  def create_pizza(self, pizza_type):
    ingredient_factory = NYPizzaIngredientFactory()
 
    if pizza_type == "cheese":
      pizza = CheesePizza(ingredient_factory)
      pizza.set_name("纽约风格芝士披萨".decode('utf-8'))
    elif pizza_type == "clam":
      pizza = ClamPizza(ingredient_factory)
      pizza.set_name("纽约风格文蛤披萨".decode('utf-8'))
    else:
      pizza = None
 
    return pizza
 
'''
芝加哥披萨实体店2
'''
class ChicagoPizzaStore(PizzaStore):
   def create_pizza(self, pizza_type):
    ingredient_factory = ChicagoPizzaIngredientFactory()
 
    if pizza_type == "cheese":
      pizza = CheesePizza(ingredient_factory)
      pizza.set_name("芝加哥风格芝士披萨".decode('utf-8'))
    elif pizza_type == "clam":
      pizza = ClamPizza(ingredient_factory)
      pizza.set_name("芝加哥风格文蛤披萨".decode('utf-8'))
    else:
      pizza = None
 
    return pizza
 
'''
生产披萨的工厂
'''
class PizzaIngredientFactory:
  def create_dough(self):
    pass
 
  def create_sauce(self):
    pass
 
  def create_cheese(self):
    pass
 
  def create_clam(self):
    pass
 
'''
生产披萨的实体工厂1
'''
class NYPizzaIngredientFactory(PizzaIngredientFactory):
  def create_dough(self):
    return ThinDough()
 
  def create_sauce(self):
    return MarinaraSauce()
 
  def create_cheese(self):
    return FreshCheese()
 
  def create_clam(self):
    return FreshClam()
 
'''
生产披萨的实体工厂2
'''
class ChicagoPizzaIngredientFactory(PizzaIngredientFactory):
  def create_dough(self):
    return ThickDough()
 
  def create_sauce(self):
    return MushroomSauce()
 
  def create_cheese(self):
    return BlueCheese()
 
  def create_clam(self):
    return FrozenClam()
 
 
class Dough:
  def to_string(self):
    pass
 
class ThinDough(Dough):
  def to_string(self):
    return "薄的面团"
 
class ThickDough(Dough):
  def to_string(self):
    return "厚的生面团"
 
class Sauce:
  def to_string(self):
    pass
 
class MarinaraSauce(Sauce):
  def to_string(self):
    return "番茄酱"
 
class MushroomSauce(Sauce):
  def to_string(self):
    return "蘑菇酱"
 
class Cheese:
  def to_string(self):
    pass
 
class FreshCheese(Cheese):
  def to_string(self):
    return "新鲜的奶酪"
 
class BlueCheese(Cheese):
  def to_string(self):
    return "蓝纹奶酪"
 
class Clam:
  def to_string(self):
    pass
 
class FreshClam(Clam):
  def to_string(self):
    return "新鲜的文蛤"
 
class FrozenClam(Clam):
  def to_string(self):
    return "冷冻的文蛤"
 
if __name__ == "__main__":
  # 创建了两个披萨实体店
  ny_store = NYPizzaStore()
  chicago_store = ChicagoPizzaStore()
 
  # 在第一个披萨对象中订购了一个cheese风味的披萨
  pizza = ny_store.order_pizza("cheese")
  print pizza.to_string()
  print "迈克订购了一个 %s" % pizza.get_name()
  print
 
  pizza = chicago_store.order_pizza("clam")
  print pizza.to_string()
  print "约翰订购了一个%s" % pizza.get_name()

结果：

准备: 纽约风格芝士披萨
烘烤25分钟在350。
切割成对角线切片。
放在官方的盒子中。
纽约风格芝士披萨:
  面团: 薄的面团
  酱汁: 番茄酱
  奶酪: 新鲜的奶酪
 
迈克订购了一个 纽约风格芝士披萨
 
准备: 芝加哥风格文蛤披萨
烘烤25分钟在350。
切割成对角线切片。
放在官方的盒子中。
芝加哥风格文蛤披萨:
  面团: 厚的生面团
  酱汁: 蘑菇酱
  文蛤: 冷冻的文蛤
 
约翰订购了一个芝加哥风格文蛤披萨

Statement of this Website

The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress images for free

Clothoff.io

AI clothes remover

AI Hentai Generator

Generate AI Hentai for free.

Show More

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)

4 weeks ago By 尊渡假赌尊渡假赌尊渡假赌

R.E.P.O. Best Graphic Settings

4 weeks ago By 尊渡假赌尊渡假赌尊渡假赌

Assassin's Creed Shadows: Seashell Riddle Solution

2 weeks ago By DDD

R.E.P.O. How to Fix Audio if You Can't Hear Anyone

4 weeks ago By 尊渡假赌尊渡假赌尊渡假赌

WWE 2K25: How To Unlock Everything In MyRise

1 months ago By 尊渡假赌尊渡假赌尊渡假赌

Show More

Hot Tools

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Show More

Hot Topics

Where is the login entrance for gmail email?

7509

15

CakePHP Tutorial

1378

52

What is the format of the account name of steam

78

11

win11 activation key permanent

52

19

nyt connections hints and answers

19

59

Show More