如何在Golang中实现自定义错误类型_Golang自定义错误处理方法汇总

type MyError struct {
    Code    int
    Message string
}

func (e *MyError) Error() string {
    return fmt.Sprintf("error %d: %s", e.Code, e.Message)
}

func something() error {
    return &MyError{Code: 400, Message: "invalid input"}
}

if err := something(); err != nil {
    if myErr, ok := err.(*MyError); ok {
        fmt.Println("Code:", myErr.Code)
    }
}

var ErrNotFound = errors.New("not found")

if errors.Is(err, ErrNotFound) {
    // 处理资源未找到的情况
}

var myErr *MyError
if errors.As(err, &myErr) {
    fmt.Println("Custom error code:", myErr.Code)
}

func readConfig() error {
    file, err := os.Open("config.json")
    if err != nil {
        return fmt.Errorf("failed to open config file: %w", err)
    }
    defer file.Close()

    _, err = io.ReadAll(file)
    if err != nil {
        return fmt.Errorf("failed to read config: %w", err)
    }
    return nil
}

var (
    ErrInvalidArgument = errors.New("invalid argument")
    ErrTimeout         = errors.New("operation timed out")
    ErrUnauthorized    = errors.New("unauthorized access")
)

func divide(a, b float64) (float64, error) {
    if b == 0 {
        return 0, ErrInvalidArgument
    }
    return a / b, nil
}