Golang代理模式动态代理实现解析

type Service interface {
    DoAction() string
    GetValue(int) string
}

type RealService struct{}

func (r *RealService) DoAction() string {
    return "Real action executed"
}

func (r *RealService) GetValue(x int) string {
    return fmt.Sprintf("Value: %d", x)
}

type DynamicProxy struct {
    target interface{}
}

func (p *DynamicProxy) Call(methodName string, args ...interface{}) []reflect.Value {
    targetValue := reflect.ValueOf(p.target)
    method := targetValue.MethodByName(methodName)

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

    return method.Call(in)
}

real := &RealService{}
proxy := &DynamicProxy{target: real}

// 代理调用
result := proxy.Call("DoAction")
fmt.Println(result[0].String()) // 输出: Real action executed

result2 := proxy.Call("GetValue", 42)
fmt.Println(result2[0].String()) // 输出: Value: 42

func (p *DynamicProxy) Call(methodName string, args ...interface{}) []reflect.Value {
    fmt.Printf("Before calling method: %s\n", methodName)

    start := time.Now()
    targetValue := reflect.ValueOf(p.target)
    method := targetValue.MethodByName(methodName)

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

    result := method.Call(in)

    elapsed := time.Since(start)
    fmt.Printf("After calling %s, duration: %v\n", methodName, elapsed)

    return result
}