工厂方法模式

2. 简单工厂

2.1 概述

指在不指定具体产品类的情况下，为相互关联的产品簇或产品集（Families of Products）提供创建接口，并向客户端隐藏具体产品创建的细节或表示的对象。

2.2 代码示例

• 对deployment,daemonset,statefulset三个类，抽象出一个WorkLoad类
• 该类有一个创建工作负载方法，该方法根据条件返回WorkLoad的一个子类
• 创建一个Option接口，对三个子类进行操作

package main

import "fmt"

type Option interface {
	Create() string
}

type Deployment struct {
	WorkLoad WorkLoad
}

func (deployment *Deployment) Create() string {
	return fmt.Sprintf("假装创建了%q：%q", deployment.WorkLoad.Kind, deployment.WorkLoad.Name)
}

type Daemonset struct {
	WorkLoad WorkLoad
}

func (daemonset *Daemonset) Create() string {
	return fmt.Sprintf("假装创建了%q：%q", daemonset.WorkLoad.Kind, daemonset.WorkLoad.Name)
}

type Statefulset struct {
	WorkLoad WorkLoad
}

func (statefulset *Statefulset) Create() string {
	return fmt.Sprintf("假装创建了%q：%q", statefulset.WorkLoad.Kind, statefulset.WorkLoad.Name)
}

type WorkLoad struct {
	Name string
	Kind string
}

func (workLoad *WorkLoad) setWorkLoad() Option {
	switch workLoad.Kind {
	case "Deployment":
		return &Deployment{
			WorkLoad: *workLoad,
		}
	case "Daemonset":
		return &Daemonset{
			WorkLoad: *workLoad,
		}
	case "Statefulset":
		return &Statefulset{
			WorkLoad: *workLoad,
		}
	}
	return nil
}

func main() {
	//简单工厂使用代码
	workLoad := &WorkLoad{
		Name: "nginx",
		Kind: "Deployment",
	}
	parse := workLoad.setWorkLoad()
	if parse != nil {
		data := parse.Create()
		fmt.Println(data)
	}
}

• 输出

假装创建了"Deployment"："nginx"

2.3 类图

classDiagram Deployment --|> WorkLoad Daemenset --|> WorkLoad Stagefulset --|> WorkLoad Option <|.. Deployment Option <|.. Daemenset Option <|.. Stagefulset class WorkLoad{ +string Name +string Kind +Option setWorkLoad() } class Deployment{ -WorkLoad WorkLoad +Create() } class Daemenset{ -WorkLoad WorkLoad +Create() } class Stagefulset{ -WorkLoad WorkLoad +Create() } class Option{ <<interface>> +string Create() }

3. 工厂模式

3.1 概述

工厂方法类定义产品对象创建接口，但由子类实现具体产品对象的创建。

3.2 代码示例

package main

import (
	"fmt"
)

type Option interface {
	Create() string
}

type Deployment struct {
	Name string
	Kind string
}

func (deployment *Deployment) Create() string {
	return fmt.Sprintf("假装创建了%q：%q", deployment.Kind, deployment.Name)
}

type Daemonset struct {
	Name string
	Kind string
}

func (daemonset *Daemonset) Create() string {
	return fmt.Sprintf("假装创建了%q：%q", daemonset.Kind, daemonset.Name)
}

type Statefulset struct {
	Name string
	Kind string
}

func (statefulset *Statefulset) Create() string {
	return fmt.Sprintf("假装创建了%q：%q", statefulset.Kind, statefulset.Name)
}

type WorkLoad struct {
	Name string
	Kind string
}

type Set interface {
	SetWorkLoad(workLoad *WorkLoad) Option
}

type SetDeployment struct {
}

func (jsonFactory *SetDeployment) SetWorkLoad(workLoad *WorkLoad) Option {
	deployemnt := &Deployment{
		Name: workLoad.Name,
		Kind: workLoad.Kind,
	}
	return deployemnt
}

type SetDaemonset struct {
}

func (setDaemonset *SetDaemonset) SetWorkLoad(workLoad *WorkLoad) Option {
	daemonset := &Deployment{
		Name: workLoad.Name,
		Kind: workLoad.Kind,
	}
	return daemonset
}

type SetStatefulset struct {
}

func (setStatefulset *SetStatefulset) SetWorkLoad(workLoad *WorkLoad) Option {
	statefulset := &Statefulset{
		Name: workLoad.Name,
		Kind: workLoad.Kind,
	}
	return statefulset
}

func SetWorkLoad(workLoad *WorkLoad) Set {
	switch workLoad.Kind {
	case "Deployment":
		return &SetDeployment{}
	case "Daemonset":
		return &SetDaemonset{}
	case "Statefulset":
		return &SetStatefulset{}
	}
	return nil
}

func main() {

	workLoad := &WorkLoad{
		Name: "nginx",
		Kind: "Deployment",
	}

	workLoadKind := SetWorkLoad(workLoad)
	workLoadConf := workLoadKind.SetWorkLoad(workLoad)
	if workLoadConf != nil {
		data := workLoadConf.Create()
		fmt.Println(data)
	}
}

3.3 类图

classDiagram Option <|.. Deployment Option <|.. Daemenset Option <|.. Stagefulset SetDeployment ..|> Set SetDaemenset ..|> Set SetStagefulset ..|> Set Deployment <.. SetDeployment Daemenset <.. SetDaemenset Stagefulset <.. SetStagefulset class Deployment{ +string Name +string Kind +Create() } class Daemenset{ +string Name +string Kind +Create() } class Stagefulset{ +string Name +string Kind +Create() } class Option{ <<interface>> +string Create() } class Set{ <<interface>> +string Create() } class SetDeployment{ +Option SetWorkLoad() } class SetDaemenset{ +Option SetWorkLoad() } class SetStagefulset{ +Option SetWorkLoad() }