57°

[go设计模式]工厂方法模式

简单工厂就是生产整个计算器,而工厂方法只生产计算器的一部分;

原有的简单工厂可以生'+' '-' '*' '/' ;但是如果添加新的部件'%',厂房就

需要扩充、修改很可以会影响原来部件的正常生产,这就违背了开放封闭原则;

而工厂方法则不存在这个问题;我新开一个工厂专门生产'%'就可以了。

package main

import ( "fmt" )

type Operation interface { Exe(int, int) int }

type FactoryAdd struct{} type OperationAdd struct{}

func (this *FactoryAdd) Create() Operation { return &OperationAdd{} }

func (this *OperationAdd) Exe(a int, b int) int { return a + b }

type FactorySub struct{} type OperationSub struct{}

func (this *FactorySub) Create() Operation { return &OperationSub{} }

func (this *OperationSub) Exe(a int, b int) int { return a - b }

type FactoryMul struct{} type OperationMul struct{}

func (this *FactoryMul) Create() Operation { return &OperationMul{} }

func (this *OperationMul) Exe(a int, b int) int { return a * b }

type FactoryDiv struct{} type OperationDiv struct{}

func (this *FactoryDiv) Create() Operation { return &OperationDiv{} }

func (this *OperationDiv) Exe(a int, b int) int { return a / b }

// 新增一个"%"操作,不影响原来的代码,符合开放封闭原则 type FactoryMod struct{} type OperationMod struct{}

func (this *FactoryMod) Create() Operation { return &OperationMod{} }

func (this *OperationMod) Exe(a int, b int) int { return a % b }

func main() {

fmt.Println(
	(&FactoryAdd{}).Create().Exe(10, 5),
	(&FactorySub{}).Create().Exe(10, 5),
	(&FactoryMul{}).Create().Exe(10, 5),
	(&FactoryDiv{}).Create().Exe(10, 5),
	(&FactoryMod{}).Create().Exe(10, 5))

}

  

输出结果:

15 5 50 2 0

 

本文转载自博客园,原文链接:https://www.cnblogs.com/atinyant/p/13061778.html

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