GolangWeb开发中的错误处理技巧 统一错误返回与日志记录方案

type ErrorResponse struct {
    Code    int    `json:"code"`
    Message string `json:"message"`
    Detail  string `json:"detail,omitempty"`
}

func SendError(w http.ResponseWriter, err error, statusCode int) {
    resp := ErrorResponse{
        Code:    statusCode,
        Message: http.StatusText(statusCode),
        Detail:  err.Error(),
    }
    w.WriteHeader(statusCode)
    json.NewEncoder(w).Encode(resp)
}

func loggingMiddleware(next http.Handler) http.Handler {
    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
        // 可以从 context 中获取 user id 等信息
        logger := log.WithFields(log.Fields{
            "path":   r.URL.Path,
            "method": r.Method,
            "ip":     r.RemoteAddr,
        })

        // 将 logger 存入 context，供后续 handler 使用
        ctx := context.WithValue(r.Context(), "logger", logger)
        next.ServeHTTP(w, r.WithContext(ctx))
    })
}

logger := ctx.Value("logger").(*log.Entry)
logger.WithError(err).Error("处理请求失败")

type AppError struct {
    Code    int
    Message string
    Err     error
}

func (e *AppError) Error() string {
    return e.Err.Error()
}

if appErr, ok := err.(*AppError); ok {
    SendError(w, appErr.Err, appErr.Code)
} else {
    SendError(w, err, http.StatusInternalServerError)
}