Golang自定义错误结构体及方法应用

type MyError struct {
    Code    int
    Message string
    Time    time.Time
}

func (e *MyError) Error() string {
    return fmt.Sprintf("[%v] ERROR %d: %s", e.Time.Format("2006-01-02 15:04:05"), e.Code, e.Message)
}

func NewMyError(code int, message string) *MyError {
    return &MyError{
        Code:    code,
        Message: message,
        Time:    time.Now(),
    }
}

func doSomething() error {
    // 模拟出错
    return NewMyError(404, "resource not found")
}

err := doSomething()
if err != nil {
    var myErr *MyError
    if errors.As(err, &myErr) {
        fmt.Printf("错误码: %d, 消息: %s, 时间: %v\n", myErr.Code, myErr.Message, myErr.Time)
    } else {
        fmt.Println("未知错误:", err)
    }
}

func (e *MyError) StatusCode() int {
    switch e.Code {
    case 404:
        return 404
    case 500:
        return 500
    default:
        return 400
    }
}

func (e *MyError) IsRetryable() bool {
    return e.Code >= 500 // 服务端错误可重试
}