gin博客项目复盘--03错误处理、数据验证

package errmsg

const (
 SUCCSE = 200
 ERROR  = 500
  // code= 1000... 用户模块的错误
 ERROR_USERNAME_USED    = 1001
 ERROR_PASSWORD_WRONG   = 1002
  //...
)

var codemsg = map[int]string{
 SUCCSE: "ok",
 ERROR: "FAIL",
  ERROR_USERNAME_USED:    "用户名已存在！",
 ERROR_PASSWORD_WRONG:   "密码错误",
  //...
}

func GetErrMsg(code int) string {
 return codemsg[code]
}

//查询用户列表
func GetUsers(c *gin.Context) {
 pageSize, _ := strconv.Atoi(c.Query("pagesize"))
 pageNum, _ := strconv.Atoi(c.Query("pagenum"))
 username := c.Query("username")

 switch {
 case pageSize >= 100:
  pageSize = 100
 case pageSize <= 0:
  pageSize = 10
 }

 if pageNum == 0 {
  pageNum = 1
 }

 data, total := model.GetUsers(username, pageSize, pageNum)
 code := errmsg.SUCCSE
 c.JSON(
  http.StatusOK, gin.H{
   "status":  code,
   "data":    data,
   "total":   total,
   "message": errmsg.GetErrMsg(code),
  },
 )
}

//GetUsers 查询用户列表
func GetUsers(username string, pageSize, pageNum int) ([]User, int64) {
 var users []User
 var total int64
 if username != "" {
  db.Select("id,username,role,created_at").Where(
   "username LIKE ?", username+"%",
  ).Limit(pageSize).Offset((pageNum - 1) * pageSize).Find(&users)

  db.Model(&users).Where(
   "username LIKE ?", username+"%",
  ).Count(&total)
  return users, total
 }
 db.Select("id,username,role,created_at").Limit(pageSize).Offset((pageNum - 1) * pageSize).Find(&users)
 db.Model(&users).Count(&total)

 return users, total
}

type User struct {
 gorm.Model
 Username string `gorm:"type:varchar(20);not null " json:"username" validate:"required,min=4,max=12" label:"用户名"`
 Password string `gorm:"type:varchar(500);not null" json:"password" validate:"required,min=6,max=120" label:"密码"`
 Role     int    `gorm:"type:int;DEFAULT:2" json:"role" validate:"required,gte=2" label:"角色码"`
}

package validator

import (
 "fmt"
 "ginVue3blog/utils/errmsg"
  //注意需要引入如下4个包
 "github.com/go-playground/locales/zh_Hans_CN" //中文包
 unTrans "github.com/go-playground/universal-translator" //翻译包
 "github.com/go-playground/validator/v10"
 zhTrans "github.com/go-playground/validator/v10/translations/zh"
 "reflect"
)

func Validate(data interface{}) (string, int) {
 validate := validator.New()
 uni := unTrans.New(zh_Hans_CN.New())
 trans, _ := uni.GetTranslator("zh_Hans_CN")

 err := zhTrans.RegisterDefaultTranslations(validate, trans)
 if err != nil {
  fmt.Println("err:", err)
 }
 validate.RegisterTagNameFunc(func(field reflect.StructField) string {
  label := field.Tag.Get("label")
  return label
 })
 err = validate.Struct(data)
 if err != nil {
  for _, v := range err.(validator.ValidationErrors) {
   return v.Translate(trans), errmsg.ERROR
  }
 }
 return "", errmsg.ERROR
}