使用ozzo-validation/v4报错：field #0 cannot be found in the struct

问题详情 #

我正在使用github.com/go-ozzo/ozzo-validation/v4进行结构体校验，定义了如下MyStruct结构体及对应的Validate方法，发送指定JSON请求后，收到错误提示：field #0 cannot be found in the struct。

结构体定义 #

type MyStruct struct {
    UUID          string `json:"uuid"`
    FirstUUID     string `json:"first_uuid"`
    SecondUUID    string `json:"second_uuid"`
    ThirdUUID     string `json:"third_uuid"`
    PhoneNumber   string `json:"phone_number"`
    Email         string `json:"email"`
    SkypeID       string `json:"skype_id"`
    City          string `json:"city"`
    Comment       string `json:"comment"`
    PersonnelID   string `json:"personnel_id"`
    FirstDate     string `json:"first_date"`
    SecondDate    string `json:"second_date"`
    FirstBoolean  bool   `json:"first_boolean"`
    SecondBoolean bool   `json:"second_boolean"`
}

校验方法 #

func (m MyStruct) Validate() error {
    err := validation.ValidateStruct(
        validation.Field(&uui.PersonnelID, validation.Match(personnelIDRegexp)),
        validation.Field(&uui.UUID, is.UUID),
        validation.Field(&uui.FirstUUID, validation.Required, is.UUID),
        validation.Field(&uui.SecondUUID, validation.Required, is.UUID),
        validation.Field(&uui.ThirdUUID, validation.Required, is.UUID),
        validation.Field(&uui.Email, validation.Required, is.Email),
        validation.Field(&uui.PhoneNumber, validation.Required, validation.Match(mobileRegexp)),
        validation.Field(&uui.City, validation.Required),
        validation.Field(&uui.Comment),
        validation.Field(&uui.SkypeID, validation.Required),
        validation.Field(&uui.FirstDate, validation.Date(time.DateOnly)),
        validation.Field(&uui.SecondDate, validation.Date(time.DateOnly)),
    )

    return err
}

请求内容 #

{
    "uuid": "1e57ef49-352f-4545-a43a-b51cad6c5a0a",
    "phone_number": "09124567891",
    "email": "email.address@gmail.com",
    "skype_id": "some_skype_id",
    "city": "a city",
    "personnel_id": "",
    "comment": "no comment for now!",
    "first_date": "",
    "second_date": "",
    "first_uuid": "94038913-2bdb-4dde-99fb-640a24e1c003",
    "second_uuid": "7fa0e242-841b-4de0-a3ce-e2b54ecd1bca",
    "third_uuid": "35ab6711-852e-42c8-aab3-dfb901a845f5",
    "first_boolean": true,
    "second_boolean": false
}

核心错误原因 #

1. 缺少结构体指针参数：validation.ValidateStruct的第一个参数必须是要校验的结构体指针，原代码完全漏掉了这个参数，导致库无法关联字段与目标结构体。
2. 字段引用错误：校验方法里所有字段都用了uui.XXX，但当前方法的接收者是m MyStruct，应该用m.XXX来访问结构体字段。uui是未定义的无效变量，库无法识别这些字段属于哪个结构体，因此抛出"field #0 cannot be found in the struct"（#0指第一个字段PersonnelID）。

额外问题提示 #

• PersonnelID字段在请求中传的是空字符串，但原校验规则仅加了正则匹配，若业务要求该字段非空，需补充validation.Required规则。
• FirstDate和SecondDate字段传的是空字符串，validation.Date规则会直接判定无效，若允许为空，需添加条件校验逻辑。

修正后的校验方法 #

func (m MyStruct) Validate() error {
    err := validation.ValidateStruct(
        &m, // 必须传入结构体指针作为第一个参数
        validation.Field(&m.PersonnelID, validation.Required, validation.Match(personnelIDRegexp)), // 补充Required规则，可根据业务调整
        validation.Field(&m.UUID, is.UUID),
        validation.Field(&m.FirstUUID, validation.Required, is.UUID),
        validation.Field(&m.SecondUUID, validation.Required, is.UUID),
        validation.Field(&m.ThirdUUID, validation.Required, is.UUID),
        validation.Field(&m.Email, validation.Required, is.Email),
        validation.Field(&m.PhoneNumber, validation.Required, validation.Match(mobileRegexp)),
        validation.Field(&m.City, validation.Required),
        validation.Field(&m.Comment),
        validation.Field(&m.SkypeID, validation.Required),
        // 允许日期字段为空，非空时校验格式
        validation.Field(&m.FirstDate, validation.When(m.FirstDate != "", validation.Date(time.DateOnly))),
        validation.Field(&m.SecondDate, validation.When(m.SecondDate != "", validation.Date(time.DateOnly))),
    )

    return err
}

内容的提问来源于stack exchange，提问作者Zeinab Abbasimazar