【设计模式】8、adapter 适配器模式

八、adapter 适配器模式

https://refactoringguru.cn/design-patterns/adapter

通常用于老旧系统, 或第三方系统, 提供一层适配器或插件, 做协议转换

PS: 如果开发新系统, 各层之间的解耦, 成为 bridge 桥接模式. 而如果是老系统则称为 adapter 适配器模式. 本质是一样的. 都是通过添加中间层实现的.

8.1 convert_lightning_to_usb

https://refactoringguru.cn/design-patterns/adapter/go/example

08adapter/081convert_lightning_to_usb
├── adapter.go
├── client.go
├── client_test.go
├── computer.go
└── readme.md

8.1.1 client_test.go

package _81convert_lightning_to_usb

import "testing"

/*
=== RUN   TestClient
insert lighting into computer
mac: insert into lightning port
insert lighting into computer
适配器: 将雷电口转换为USB口
windows: insert into usb port
--- PASS: TestClient (0.00s)
PASS
*/
func TestClient(t *testing.T) {
	mac := &mac{}
	windowsAdapter := &windowsAdapter{windowsComputer: &windows{}}

	c := &client{}
	c.InsertLightningIntoComputer(mac)
	c.InsertLightningIntoComputer(windowsAdapter)
}

8.1.2 client.go

package _81convert_lightning_to_usb

import "fmt"

type client struct {
}

func (c *client) InsertLightningIntoComputer(computer computer) {
	fmt.Println("insert lighting into computer")
	computer.InsertIntoLightningPort()
}

8.1.3 computer.go

package _81convert_lightning_to_usb

import "fmt"

type computer interface {
	InsertIntoLightningPort()
}

type mac struct{}

func (c *mac) InsertIntoLightningPort() {
	fmt.Println("mac: insert into lightning port")
}

type windows struct{}

func (c *windows) InsertIntoUSBPort() {
	// windows 只支持 usb 口, 不支持雷电口
	fmt.Println("windows: insert into usb port")
}

8.1.4 adapter.go

package _81convert_lightning_to_usb

import "fmt"

type windowsAdapter struct {
	windowsComputer *windows
}

func (a *windowsAdapter) InsertIntoLightningPort() {
	fmt.Println("适配器: 将雷电口转换为USB口")
	a.windowsComputer.InsertIntoUSBPort()
}