项目结构：
/*
# 版权所有 2026 ©涂聚文有限公司™ ®
# 许可信息查看：言語成了邀功盡責的功臣，還需要行爲每日來值班嗎
# 描述：Flyweight Pattern享元模式
# Author : geovindu,Geovin Du 涂聚文.
# IDE : goLang 2024.3.6 go 26.2
# os : windows 10
# database : mysql 9.0 sql server 2019, postgreSQL 17.0 Oracle 21c Neo4j
# Datetime : 2026/4/20 21:00
# User : geovindu
# Product : GoLand
# Project : godesginpattern
# File : jewelry_category.go
*/
package flyweightimport ("fmt""godesginpattern/flyweight/errors"
)// JewelryCategoryFlyweight 享元接口（共享内部状态）
type JewelryCategoryFlyweight interface {CategoryID() stringCategoryName() stringMaterial() stringStyle() stringBasePrice() float64BaseInfo() string
}// jewelryCategory 实现
type jewelryCategory struct {categoryID stringcategoryName stringmaterial stringstyle stringbasePrice float64
}func (j *jewelryCategory) CategoryID() string { return j.categoryID }
func (j *jewelryCategory) CategoryName() string { return j.categoryName }
func (j *jewelryCategory) Material() string { return j.material }
func (j *jewelryCategory) Style() string { return j.style }
func (j *jewelryCategory) BasePrice() float64 { return j.basePrice }func (j *jewelryCategory) BaseInfo() string {return fmt.Sprintf("品类ID:%s | 名称:%s | 材质:%s | 款式:%s | 基础价:%.2f",j.categoryID, j.categoryName, j.material, j.style, j.basePrice)
}// NewJewelryCategory 创建享元
func NewJewelryCategory(id, name, material, style string, basePrice float64) (JewelryCategoryFlyweight, error) {if id == "" {return nil, errors.ErrCategoryEmpty}return &jewelryCategory{categoryID: id,categoryName: name,material: material,style: style,basePrice: basePrice,}, nil
}/*
# 版权所有 2026 ©涂聚文有限公司™ ®
# 许可信息查看：言語成了邀功盡責的功臣，還需要行爲每日來值班嗎
# 描述：Flyweight Pattern享元模式
# Author : geovindu,Geovin Du 涂聚文.
# IDE : goLang 2024.3.6 go 26.2
# os : windows 10
# database : mysql 9.0 sql server 2019, postgreSQL 17.0 Oracle 21c Neo4j
# Datetime : 2026/4/20 21:00
# User : geovindu
# Product : GoLand
# Project : godesginpattern
# File : inventory.go
*/
package inventoryimport ("fmt""godesginpattern/flyweight/domain/flyweight"
)type JewelryStatus stringconst (StatusOnSale JewelryStatus = "在售"StatusSoldOut JewelryStatus = "已售罄"StatusOffline JewelryStatus = "已下架"
)// JewelryInventory 库存实体（外部状态）
type JewelryInventory struct {UniqueCode stringStockNum intOnlineTime stringSalePrice float64Status JewelryStatusCategory flyweight.JewelryCategoryFlyweight
}func (j *JewelryInventory) FullInfo() string {return fmt.Sprintf("[%s] %s | 唯一码:%s | 库存:%d | 售价:%.2f | 状态:%s",j.Category.CategoryID(), j.Category.BaseInfo(),j.UniqueCode, j.StockNum, j.SalePrice, j.Status,)
}
/*
# 版权所有 2026 ©涂聚文有限公司™ ®
# 许可信息查看：言語成了邀功盡責的功臣，還需要行爲每日來值班嗎
# 描述：Flyweight Pattern享元模式
# Author : geovindu,Geovin Du 涂聚文.
# IDE : goLang 2024.3.6 go 26.2
# os : windows 10
# database : mysql 9.0 sql server 2019, postgreSQL 17.0 Oracle 21c Neo4j
# Datetime : 2026/4/20 20:59
# User : geovindu
# Product : GoLand
# Project : godesginpattern
# File : category_factory.go
*/
package factoryimport ("context""godesginpattern/flyweight/domain/flyweight""log""sync"
)// FlyweightFactory 享元工厂接口
type FlyweightFactory interface {GetCategory(ctx context.Context, req NewCategoryReq) (flyweight.JewelryCategoryFlyweight, error)Count() int
}type NewCategoryReq struct {CategoryID stringCategoryName stringMaterial stringStyle stringBasePrice float64
}// categoryFactory 实现
type categoryFactory struct {mu sync.RWMutexcache map[string]flyweight.JewelryCategoryFlyweight
}func NewCategoryFactory() FlyweightFactory {return &categoryFactory{cache: make(map[string]flyweight.JewelryCategoryFlyweight),}
}func (f *categoryFactory) GetCategory(ctx context.Context, req NewCategoryReq) (flyweight.JewelryCategoryFlyweight, error) {f.mu.RLock()cate, ok := f.cache[req.CategoryID]f.mu.RUnlock()if ok {log.Printf("[工厂] 复用品类：%s", req.CategoryID)return cate, nil}f.mu.Lock()defer f.mu.Unlock()if cate, ok = f.cache[req.CategoryID]; ok {return cate, nil}newCate, err := flyweight.NewJewelryCategory(req.CategoryID, req.CategoryName, req.Material, req.Style, req.BasePrice,)if err != nil {return nil, err}f.cache[req.CategoryID] = newCatelog.Printf("[工厂] 创建新品类：%s", req.CategoryID)return newCate, nil
}func (f *categoryFactory) Count() int {f.mu.RLock()defer f.mu.RUnlock()return len(f.cache)
}
/*
# 版权所有 2026 ©涂聚文有限公司™ ®
# 许可信息查看：言語成了邀功盡責的功臣，還需要行爲每日來值班嗎
# 描述：Flyweight Pattern享元模式
# Author : geovindu,Geovin Du 涂聚文.
# IDE : goLang 2024.3.6 go 26.2
# os : windows 10
# database : mysql 9.0 sql server 2019, postgreSQL 17.0 Oracle 21c Neo4j
# Datetime : 2026/4/20 20:59
# User : geovindu
# Product : GoLand
# Project : godesginpattern
# File : inventory_service.go
*/
package serviceimport ("context""godesginpattern/flyweight/domain/flyweight""godesginpattern/flyweight/domain/inventory""godesginpattern/flyweight/errors""log"
)// InventoryService 库存服务接口
type InventoryService interface {CreateInventory(ctx context.Context, req CreateInventoryReq) *inventory.JewelryInventoryQuery(ctx context.Context, inv *inventory.JewelryInventory) stringSaleOut(ctx context.Context, inv *inventory.JewelryInventory, num int) error
}type CreateInventoryReq struct {UniqueCode stringOnlineTime stringSalePrice float64Category flyweight.JewelryCategoryFlyweight
}// inventoryService 实现
type inventoryService struct{}func NewInventoryService() InventoryService {return &inventoryService{}
}func (s *inventoryService) CreateInventory(ctx context.Context, req CreateInventoryReq) *inventory.JewelryInventory {return &inventory.JewelryInventory{UniqueCode: req.UniqueCode,StockNum: 1,OnlineTime: req.OnlineTime,SalePrice: req.SalePrice,Status: inventory.StatusOnSale,Category: req.Category,}
}func (s *inventoryService) Query(ctx context.Context, inv *inventory.JewelryInventory) string {return inv.FullInfo()
}func (s *inventoryService) SaleOut(ctx context.Context, inv *inventory.JewelryInventory, num int) error {if inv.StockNum < num {return errors.ErrStockNotEnough}inv.StockNum -= numif inv.StockNum == 0 {inv.Status = inventory.StatusSoldOut}log.Printf("[销售] 出库成功：%s 剩余:%d", inv.UniqueCode, inv.StockNum)return nil
}
/*
# 版权所有 2026 ©涂聚文有限公司™ ®
# 许可信息查看：言語成了邀功盡責的功臣，還需要行爲每日來值班嗎
# 描述：Flyweight Pattern享元模式
# Author : geovindu,Geovin Du 涂聚文.
# IDE : goLang 2024.3.6 go 26.2
# os : windows 10
# database : mysql 9.0 sql server 2019, postgreSQL 17.0 Oracle 21c Neo4j
# Datetime : 2026/4/20 20:59
# User : geovindu
# Product : GoLand
# Project : godesginpattern
# File : jewelry_api.go
*/
package apiimport ("context""fmt""godesginpattern/flyweight/config""godesginpattern/flyweight/domain/inventory""godesginpattern/flyweight/infrastructure/factory""godesginpattern/flyweight/service"
)// JewelryAPI 对外接口层
type JewelryAPI struct {config *config.AppConfigfactory factory.FlyweightFactoryservice service.InventoryService
}func NewJewelryAPI(cfg *config.AppConfig,f factory.FlyweightFactory,s service.InventoryService,
) *JewelryAPI {return &JewelryAPI{config: cfg,factory: f,service: s,}
}// BatchCreate 批量创建库存
func (api *JewelryAPI) BatchCreate(ctx context.Context, req factory.NewCategoryReq, count int) ([]*inventory.JewelryInventory, error) {cate, err := api.factory.GetCategory(ctx, req)if err != nil {return nil, err}var list []*inventory.JewelryInventoryfor i := 1; i <= count; i++ {inv := api.service.CreateInventory(ctx, service.CreateInventoryReq{UniqueCode: fmt.Sprintf("JM%06d", i),OnlineTime: "2025-01-10",SalePrice: cate.BasePrice() - 300,Category: cate,})list = append(list, inv)}return list, nil
}
/*
# 版权所有 2026 ©涂聚文有限公司™ ®
# 许可信息查看：言語成了邀功盡責的功臣，還需要行爲每日來值班嗎
# 描述：Flyweight Pattern享元模式
# Author : geovindu,Geovin Du 涂聚文.
# IDE : goLang 2024.3.6 go 26.2
# os : windows 10
# database : mysql 9.0 sql server 2019, postgreSQL 17.0 Oracle 21c Neo4j
# Datetime : 2026/4/20 21:00
# User : geovindu
# Product : GoLand
# Project : godesginpattern
# File : config.go
*/
package configtype AppConfig struct {AppName stringVersion string
}func NewDefaultConfig() *AppConfig {return &AppConfig{AppName: "jewelry-inventory-system",Version: "v1.0.0",}
}
/*
# 版权所有 2026 ©涂聚文有限公司™ ®
# 许可信息查看：言語成了邀功盡責的功臣，還需要行爲每日來值班嗎
# 描述：Flyweight Pattern享元模式
# Author : geovindu,Geovin Du 涂聚文.
# IDE : goLang 2024.3.6 go 26.2
# os : windows 10
# database : mysql 9.0 sql server 2019, postgreSQL 17.0 Oracle 21c Neo4j
# Datetime : 2026/4/20 20:59
# User : geovindu
# Product : GoLand
# Project : godesginpattern
# File : errors.go
*/
package errorsimport "errors"var (ErrStockNotEnough = errors.New("库存不足")ErrCategoryEmpty = errors.New("品类ID不能为空")
)
调用：
/*
# 版权所有 2026 ©涂聚文有限公司™ ®
# 许可信息查看：言語成了邀功盡責的功臣，還需要行爲每日來值班嗎
# 描述：Flyweight Pattern享元模式
# Author : geovindu,Geovin Du 涂聚文.
# IDE : goLang 2024.3.6 go 26.2
# os : windows 10
# database : mysql 9.0 sql server 2019, postgreSQL 17.0 Oracle 21c Neo4j
# Datetime : 2026/4/20 21:03
# User : geovindu
# Product : GoLand
# Project : godesginpattern
# File : flyweightbll.go
flyweight/
├── go.mod # Go 模块
├── cmd/
│ └── main.go # 项目启动入口
├── config/
│ └── config.go # 应用配置
├── domain/
│ ├── flyweight/
│ │ └── jewelry_category.go # 享元（共享内部状态）
│ └── inventory/
│ └── inventory.go # 库存实体（外部状态）
├── infrastructure/
│ └── factory/
│ └── category_factory.go # 享元工厂（缓存/复用）
├── service/
│ └── inventory_service.go # 业务逻辑层
├── api/
│ └── jewelry_api.go # 对外接口/流程编排
└── common/└── errors/└── errors.go # 全局统一错误
*/
package bllimport ("context""godesginpattern/flyweight/api""godesginpattern/flyweight/config""godesginpattern/flyweight/infrastructure/factory""godesginpattern/flyweight/service""log"
)func FlyweightMain() {ctx := context.Background()cfg := config.NewDefaultConfig()// 依赖注入f := factory.NewCategoryFactory()s := service.NewInventoryService()api := api.NewJewelryAPI(cfg, f, s)log.Println("=== 珠宝库存销售系统启动 ===")// 创建10000件钻戒diamond, _ := api.BatchCreate(ctx, factory.NewCategoryReq{CategoryID: "C001",CategoryName: "钻戒",Material: "18K金",Style: "经典六爪",BasePrice: 5999,}, 10000)// 创建5000件黄金项链gold, _ := api.BatchCreate(ctx, factory.NewCategoryReq{CategoryID: "C002",CategoryName: "黄金项链",Material: "足金999",Style: "简约锁骨链",BasePrice: 2999,}, 5000)log.Printf("总库存：%d", len(diamond)+len(gold))log.Printf("共享享元对象：%d", f.Count())// 查询 & 销售log.Println("\n=== 库存查询 ===")log.Println(s.Query(ctx, diamond[0]))log.Println("\n=== 销售出库 ===")_ = s.SaleOut(ctx, diamond[0], 1)log.Println(s.Query(ctx, diamond[0]))
}
输出：
