【建议收藏】如何用Go写出优美的代码-Go的设计模式【装饰器模式，门面模式，亨元模式】篇五

package main

import "fmt"

func main() {
 m := MachineGun{}
 m.Shooting()
 s := SniperRifleGun{}
 s.Shooting()
}

// 抽象构件
type DecorateGunInterface interface {
 Shooting()
}

// 具体构件, 枪射击
type Gun struct {
}

func (g *Gun) Shooting() {
 fmt.Println("枪射击")
}

// 抽象装饰角色， 这里是目标对象添加功能
type MachineDecorator struct {
 Machine Gun
}

// 具体装饰，机关枪
type MachineGun struct {
 Gun MachineDecorator
}

func (m *MachineGun) Shooting() {
 fmt.Println("机关")
 m.Gun.Machine.Shooting()
}

// 具体装饰，狙击枪
type SniperRifleGun struct {
 Gun MachineDecorator
}

func (m *SniperRifleGun) Shooting() {
 fmt.Println("狙击")
 m.Gun.Machine.Shooting()
}

机关
枪射击
狙击  
枪射击

package main

import "fmt"

// 客户角色
func main() {
 GetFacadeDetail()
}

type Product struct {
}

// 子系统角色A
func (p *Product) GetProductInfo() {
 fmt.Println("这里是获取商品详情的信息接口")
}

type Stock struct {
}

// 子系统角色B
func (s *Stock) GetStockInfo() {
 fmt.Println("这里是获取库存信息接口")
}

type Ad struct {
}

// 子系统角色C
func (a *Ad) GetAdInfo() {
 fmt.Println("这里是获取广告营销的信息接口")
}

// 外观角色
func GetFacadeDetail() {
 p := Product{}
 a := Ad{}
 s := Stock{}
 p.GetProductInfo()
 a.GetAdInfo()
 s.GetStockInfo()
 fmt.Println("详情页面所哟的接口...")
}

package main

import (
 "fmt"
 "sync"
)

func main() {
 // 创建亨元
 f := NewFlyWeightPattern()

 // 具体亨元角色
 b := NewGunBase()
 f.SetElement("a1", b)
 // 读取亨元数据
 p := f.GetElement("a1").(GunProperty)
 fmt.Println(p.Shoot())

 // 非享元角色
 b2 := NewSubMachineGun(b, "auto")
 f.SetElement("b1", b2)
 // 读取享元角色数据
 p2 := f.GetElement("b1").(GunProperty)
 fmt.Println(p2.Shoot())
}

// 设计枪属性 具体享元角色
type GunProperty interface {
 // 射击属性
 Shoot() string
}

type GunBase struct {
 ShootType string
}

func NewGunBase() *GunBase {
 return &GunBase{"manual"}
}

func (g *GunBase) Shoot() string {
 return g.ShootType
}

// 冲锋枪
type SubMachineGun struct {
 base      GunProperty
 AutoShoot string
}

func NewSubMachineGun(base GunProperty, shootType string) *SubMachineGun {
 return &SubMachineGun{base, shootType}
}

func (s *SubMachineGun) Shoot() string {
 return s.base.Shoot() + s.AutoShoot
}

// 抽象享元角色
type Element struct {
 value interface{}
}

func NewElement(value interface{}) *Element {
 return &Element{value}
}

// 享元工厂角色
type FlyWeightPattern struct {
 pool map[string]*Element
 m    *sync.RWMutex
}

func (f *FlyWeightPattern) GetElement(key string) interface{} {
 f.m.RLock()
 defer f.m.RUnlock()
 return f.pool[key].value
}

func (f *FlyWeightPattern) SetElement(key string, value interface{}) {
 n := NewElement(value)
 f.m.Lock()
 defer f.m.Unlock()
 f.pool[key] = n
}

func NewFlyWeightPattern() *FlyWeightPattern {
 f := FlyWeightPattern{}
 f.pool = map[string]*Element{}
 f.m = &sync.RWMutex{}
 return &f
}

manual
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