go语言 从结构体中获取某个字段的值（反射+泛型）

package utils

import (
    "errors"
    "fmt"
    "reflect"
)

func GetStructStringField(input interface{}, key string) (value string, err error) {
    v, err := getStructField(input, key)
    if err != nil {
        return
    }
    value, ok := v.(string)
    if !ok {
        return value, errors.New("can‘t convert key‘v to string")
    }
    return
}

func GetStructFloat64Field(input interface{}, key string) (value float64, err error) {
    v, err := getStructField(input, key)
    if err != nil {
        return
    }
    value, ok := v.(float64)
    if !ok {
        return value, errors.New("can‘t convert key‘v to float64")
    }
    return
}

func getStructField(input interface{}, key string) (value interface{}, err error) {
    rv := reflect.ValueOf(input)
    rt := reflect.TypeOf(input)
    if rt.Kind() != reflect.Struct {
        return value, errors.New("input must be struct")
    }

    keyExist := false
    for i := 0; i < rt.NumField(); i++ {
        curField := rv.Field(i)
        if rt.Field(i).Name == key {
            switch curField.Kind() {
            case reflect.String, reflect.Int64, reflect.Int32, reflect.Int16, reflect.Int8, reflect.Int, reflect.Float64, reflect.Float32:
                keyExist = true
                value = curField.Interface()
            default:
                return value, errors.New("key must be int float or string")
            }
        }
    }
    if !keyExist {
        return value, errors.New(fmt.Sprintf("key %s not found in %s‘s field", key, rt))
    }
    return
}

func TestGetStructFiled(t *testing.T) {
	user1 := User{
		ID:   1,
		NAME: "aaa",
	}
	v, err := GetStructStringField(user1, "NAME")
	fmt.Println(v, err)
}

aaa <nil>