答案是使用Go的結(jié)構(gòu)體、接口和反射實(shí)現(xiàn)輕量級(jí)DI容器。通過定義包含服務(wù)映射的Container結(jié)構(gòu)體，注冊(cè)構(gòu)造函數(shù)并利用反射解析依賴，實(shí)現(xiàn)自動(dòng)注入。支持按類型存儲(chǔ)和檢索服務(wù)實(shí)例，確保松耦合與可測(cè)試性，適用于簡單場(chǎng)景，復(fù)雜需求可選用uber/dig等庫。

Implementing a dependency injection (DI) container in Go doesn't require a complex framework. You can build a lightweight, effective DI container using Go's standard features like structs, interfaces, and reflection. The goal is to manage object creation and their dependencies automatically, reducing coupling and improving testability.

1. Define the Container Structure

A DI container holds instances or constructors of services. Use a map to store named dependencies, and leverage interface{} or reflect.Type as keys.

Example:

type Container struct {<br>    services map[reflect.Type]reflect.Value<br>}<br><br>func NewContainer() *Container {<br>    return &Container{<br>        services: make(map[reflect.Type]reflect.Value),<br>    }<br>}

2. Register Services

Add methods to register types or factory functions. You can support both concrete structs and constructor functions that return instances.

Example:

func (c *Container) Register(factory interface{}) {<br>    factoryValue := reflect.ValueOf(factory)<br>    result := factoryValue.Call(nil)[0]<br>    c.services[result.Type()] = result<br>}

3. Resolve Dependencies

When resolving a type, check if it's already built. If not, call its constructor and inject any required dependencies by recursively resolving them.

For more advanced cases, inspect constructor parameters using reflection and resolve each one from the container.

Example Resolve method:

func (c *Container) Get(t reflect.Type) reflect.Value {<br>    if service, exists := c.services[t]; exists {<br>        return service<br>    }<br>    panic("service not found: "   t.Name())<br>}

4. Usage Example

Define services and wire them together through the container.

type Database struct{}<br>func NewDatabase() *Database { return &Database{} }<br><br>type UserService struct {<br>    DB *Database<br>}<br>func NewUserService(db *Database) *UserService {<br>    return &UserService{DB: db}<br>}<br><br>// In main:<br>container := NewContainer()<br>container.Register(NewDatabase)<br>container.Register(func() *UserService {<br>    return NewUserService(container.Get(reflect.TypeOf((*Database)(nil)).Elem()).Interface().(*Database))<br>})<br><br>userSvc := container.Get(reflect.TypeOf((*UserService)(nil)).Elem()).Interface().(*UserService)

Basically just map types to instances or factories, use reflection to wire them, and resolve on demand. Keep it simple unless you need lifecycle management or scopes. There are also solid open-source options like uber/dig if you prefer a full-featured DI library.

以上是如何在Golang中實(shí)現(xiàn)依賴注入容器的詳細(xì)內(nèi)容。更多信息請(qǐng)關(guān)注PHP中文網(wǎng)其他相關(guān)文章！