将地图转换为结构 [英] Converting map to struct
本文介绍了将地图转换为结构的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我试图在Go中创建一个通用方法,它将使用来自 map [string] interface {}的数据填充
struct
code>。例如,方法签名和用法可能如下所示:
func FillStruct(数据映射[字符串]接口{},结果接口{}){
...
}
类型MyStruct结构{
名称字符串
年龄int64
}
myData:= make(map [string] interface {})
myData [Name] =Tony
myData [Age] = 23
结果:=& MyStruct {}
FillStruct(myData,result)
//结果现在将Name设置为Tony,Age设置为23
我知道这可以使用JSON作为中介来完成;是否还有另一种更有效的方法呢?
解决方案
这与西蒙的回答是一样的,但有一点错误处理:
http://play.golang.org/p/tN8mxT_V9h
func SetField(obj interface {},name string,value interface {})error {
structValue:= reflect.ValueOf(obj).Elem()
structFieldValue:= structValue.FieldByName(name)
if!structFieldValue.IsValid(){
return fmt.Errorf (没有这样的字段:%s在obj中,名称)
}
if!structFieldValue.CanSet(){
return fmt.Errorf(Can not set%s field value),name)
}
structFieldType:= structFieldValue.Type()
val:= reflect.ValueOf(value)
如果structFieldType!= val.Type (){
return errors.New(提供的值类型不匹配obj字段类型)
}
st ructFieldValue.Set(val)
返回nil
}
类型MyStruct结构{
名称字符串
年龄int64
}
func(s * MyStruct)FillStruct(m map [string] interface {})error {
for k,v:= range m {
err:= SetField(s,k,v )
如果err!= nil {
返回err
}
}
返回nil
}
func main() {
myData:= make(map [string] interface {})
myData [Name] =Tony
myData [Age] = int64(23)
结果:=& MyStruct {}
err:= result.FillStruct(myData)
if err!= nil {
fmt.Println(err)
}
fmt.Println(结果)
}
I am trying to create a generic method in Go that will fill a struct
using data from a map[string]interface{}
. For example, the method signature and usage might look like:
func FillStruct(data map[string]interface{}, result interface{}) {
...
}
type MyStruct struct {
Name string
Age int64
}
myData := make(map[string]interface{})
myData["Name"] = "Tony"
myData["Age"] = 23
result := &MyStruct{}
FillStruct(myData, result)
// result now has Name set to "Tony" and Age set to 23
I know this can be done using JSON as an intermediary; is there another more efficient way of doing this?
解决方案
This is the same idea as Simon's answer, but with a little more error handling:
http://play.golang.org/p/tN8mxT_V9h
func SetField(obj interface{}, name string, value interface{}) error {
structValue := reflect.ValueOf(obj).Elem()
structFieldValue := structValue.FieldByName(name)
if !structFieldValue.IsValid() {
return fmt.Errorf("No such field: %s in obj", name)
}
if !structFieldValue.CanSet() {
return fmt.Errorf("Cannot set %s field value", name)
}
structFieldType := structFieldValue.Type()
val := reflect.ValueOf(value)
if structFieldType != val.Type() {
return errors.New("Provided value type didn't match obj field type")
}
structFieldValue.Set(val)
return nil
}
type MyStruct struct {
Name string
Age int64
}
func (s *MyStruct) FillStruct(m map[string]interface{}) error {
for k, v := range m {
err := SetField(s, k, v)
if err != nil {
return err
}
}
return nil
}
func main() {
myData := make(map[string]interface{})
myData["Name"] = "Tony"
myData["Age"] = int64(23)
result := &MyStruct{}
err := result.FillStruct(myData)
if err != nil {
fmt.Println(err)
}
fmt.Println(result)
}
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