如何将json解码为结构
我正在尝试在Go中解码一些json，但是某些字段没有被解码. 请参见此处:
I'm trying to decode some json in Go but some fields don't get decoded. See the code running in browser here:
我在做什么错了?
我只需要MX记录，所以我没有定义其他字段.据我从godoc了解到，您不需要定义不需要/不需要的字段.
I need only the MX records so I didn't define the other fields. As I understand from the godoc you don't need to define the fields you don't use/need.
// You can edit this code!
// Click here and start typing.
package main
import "fmt"
import "encoding/json"
func main() {
body := `
{"response": {
"status": "SUCCESS",
"data": {
"mxRecords": [
{
"value": "us2.mx3.mailhostbox.com.",
"ttl": 1,
"priority": 100,
"hostName": "@"
},
{
"value": "us2.mx1.mailhostbox.com.",
"ttl": 1,
"priority": 100,
"hostName": "@"
},
{
"value": "us2.mx2.mailhostbox.com.",
"ttl": 1,
"priority": 100,
"hostName": "@"
}
],
"cnameRecords": [
{
"aliasHost": "pop.a.co.uk.",
"canonicalHost": "us2.pop.mailhostbox.com."
},
{
"aliasHost": "webmail.a.co.uk.",
"canonicalHost": "us2.webmail.mailhostbox.com."
},
{
"aliasHost": "smtp.a.co.uk.",
"canonicalHost": "us2.smtp.mailhostbox.com."
},
{
"aliasHost": "imap.a.co.uk.",
"canonicalHost": "us2.imap.mailhostbox.com."
}
],
"dkimTxtRecord": {
"domainname": "20a19._domainkey.a.co.uk",
"value": "\"v=DKIM1; g=*; k=rsa; p=DkfbhO8Oyy0E1WyUWwIDAQAB\"",
"ttl": 1
},
"spfTxtRecord": {
"domainname": "a.co.uk",
"value": "\"v=spf1 redirect=_spf.mailhostbox.com\"",
"ttl": 1
},
"loginUrl": "us2.cp.mailhostbox.com"
}
}}`
type MxRecords struct {
value string
ttl int
priority int
hostName string
}
type Data struct {
mxRecords []MxRecords
}
type Response struct {
Status string `json:"status"`
Data Data `json:"data"`
}
type apiR struct {
Response Response
}
var r apiR
err := json.Unmarshal([]byte(body), &r)
if err != nil {
fmt.Printf("err was %v", err)
}
fmt.Printf("decoded is %v", r)
}
根据有关 json的转到文档，取消编组，您只能对导出的字段进行解码，主要原因是外部程序包(例如encoding/json)无法访问未导出的字段.
As per the go documentaiton about json.Unmarshal, you can only decode toward exported fields, the main reason being that external packages (such as encoding/json) cannot acces unexported fields.
如果您的json不遵循名称的go约定，则可以在字段中使用json标记来更改json键和struct字段之间的匹配.
If your json doesn't follow the go convention for names, you can use the json tag in your fields to change the matching between json key and struct field.
示例:
package main
import (
"fmt"
"encoding/json"
)
type T struct {
Foo string `json:"foo"`
}
func main() {
text := []byte(`{"foo":"bar"}`)
var t T
err := json.Unmarshal(text, &t)
if err != nil {
panic(err)
}
fmt.Println(t)
}