Golang简单项目中接口错误统一处理

type Response struct {
    Code int         `json:"code"`
    Msg  string      `json:"msg"`
    Data interface{} `json:"data,omitempty"`
}

func Success(data interface{}) *Response {
    return &Response{Code: 0, Msg: "ok", Data: data}
}

func Error(code int, msg string) *Response {
    return &Response{Code: code, Msg: msg}
}
</font>

if name == "" {
    return Error(400, "缺少用户名")
}

type AppError struct {
    Code int
    Msg  string
}

func (e AppError) Error() string {
    return e.Msg
}

func Handle(h func(http.ResponseWriter, *http.Request) error) http.HandlerFunc {
    return func(w http.ResponseWriter, r *http.Request) {
        w.Header().Set("Content-Type", "application/json")
        err := h(w, r)
        if err != nil {
            var appErr AppError
            if errors.As(err, &appErr) {
                json.NewEncoder(w).Encode(Error(appErr.Code, appErr.Msg))
            } else {
                json.NewEncoder(w).Encode(Error(500, "系统错误"))
            }
            return
        }
    }
}

const (
    ErrInvalidParam = iota + 1000
    ErrUnauthorized
    ErrServerInternal
)

if user == nil {
    return AppError{Code: ErrUnauthorized, Msg: "用户未登录"}
}