Golang代理对象与权限控制实战示例

type UserService interface {
    CreateUser(name string)
    DeleteUser(id int)
}

type RealUserService struct{}

func (r *RealUserService) CreateUser(name string) {
    println("创建用户:", name)
}

func (r *RealUserService) DeleteUser(id int) {
    println("删除用户ID:", id)
}

// 代理结构体
type UserServiceProxy struct {
    service   *RealUserService
    isAdmin   bool
}

func (p *UserServiceProxy) CreateUser(name string) {
    p.service.CreateUser(name)
}

func (p *UserServiceProxy) DeleteUser(id int) {
    if !p.isAdmin {
        println("拒绝操作：权限不足")
        return
    }
    p.service.DeleteUser(id)
}

service := &RealUserService{}
proxy := &UserServiceProxy{service: service, isAdmin: false}

proxy.CreateUser("Alice")     // 正常执行
proxy.DeleteUser(1)           // 拒绝操作

// 切换为管理员
proxy.isAdmin = true
proxy.DeleteUser(2)           // 成功删除

import (
    "fmt"
    "reflect"
)

type SecureProxy struct {
    target   interface{}
    methodPerms map[string]bool  // 方法名 -> 是否允许调用
}

func NewSecureProxy(target interface{}, perms map[string]bool) *SecureProxy {
    return &SecureProxy{
        target:      target,
        methodPerms: perms,
    }
}

func (p *SecureProxy) Call(methodName string, args ...interface{}) []reflect.Value {
    method := reflect.ValueOf(p.target).MethodByName(methodName)
    if !method.IsValid() {
        panic("方法不存在: " + methodName)
    }

    if !p.methodPerms[methodName] {
        fmt.Println("权限拒绝:", methodName)
        return nil
    }

    in := make([]reflect.Value, len(args))
    for i, arg := range args {
        in[i] = reflect.ValueOf(arg)
    }

    return method.Call(in)
}

perms := map[string]bool{
    "CreateUser": true,
    "DeleteUser": false,
}

proxy := NewSecureProxy(&RealUserService{}, perms)
proxy.Call("CreateUser", "Bob")    // 允许
proxy.Call("DeleteUser", 1)        // 拒绝