go 依赖注入 简单 例子 inject
package main
import (
"fmt"
"github.com/facebookgo/inject"
)
type DBEngine struct {
Name string
}
type UserDB struct {
Db *DBEngine `inject:""`
}
type UserService struct {
Db *UserDB `inject:""`
}
type App struct {
Name string
User *UserService `inject:""`
}
func (a *App) Create() string {
return "create app, in db name:" + a.User.Db.Db.Name+" app name :"+ a.Name
}
type Object struct {
App *App
}
func Init() *Object {
db := DBEngine{Name: "db1"}
var g inject.Graph
app := App{Name: "go-app"}
_ = g.Provide(
&inject.Object{Value: &app},
&inject.Object{Value: &db},
)
_ = g.Populate()
return &Object{
App: &app,
}
}
func main() {
obj := Init()
fmt.Println(obj.App.Create())
}