下面给出简单的代码,这里通过将变量重置为零来实现过滤字段的目的:
type student struct {
Age int `json:"age,omitempty"`
Name string `json:"name,omitempty"`
School string `json:"school,omitempty"`
}
var st = student{
Age: 10,
Name: "john smith",
School: "a high school",
}
var dic = map[string]int{
"age": 0,
"name": 1,
"school": 2,
}
var filters = []string{
"name",
"school",
}
func initStudentElems(st *student, fields []string) bool {
v := reflect.Indirect(reflect.ValueOf(st))
for _, field := range fields {
idx, exist := dic[field]
if !exist {
return false
}
vf := v.Field(idx)
vf.Set(reflect.Zero(vf.Type()))
}
return true
}
func printMarshalIdent(st *student) error {
b, err := json.MarshalIndent(st, "", " ")
if err != nil {
return err
}
fmt.Println(string(b))
return nil
}
func main() {
printMarshalIdent(&st)
initStudentElems(&st, filters)
printMarshalIdent(&st)
}
如果不希望使用二次映射，可以考虑使用reflect库中，Value结构体的FieldByName成员函数。