go - go语言解析嵌套JSON

Question

我如何从下面的 JSON 中解析和提取某些值

这是示例 JSON 响应

{
   "success":true,
   "endpoint":"https://api.abcxyz.com",
   "info":{
      "Guestconnected":134,
      "Guestratio":100000.06963,
      "symbol1":{
         "code":"NY",
         "symbol":"*",
         "name":"newyear",
         "codev":391.78161,
         "symbolAppearsAfter":false,
         "local":true
      },
      "symbol2":{
         "code":"HNY",
         "symbol":"@",
         "name":"HappyNewYear",
         "codev":1000000.0960,
         "symbolAppearsAfter":true,
         "local":false
      },
      "latest":{
         "value":1597509,
         "autovalue":"00099cf8da58a36c08f2ef98650ff6043ddfb",
         "height":474696,
         "time":1499527696
      }
   },
   "Allguest":{
      "all":4,
      "filtered":4,
      "total_invitations":15430,
      "sent_invitations":15430,
      "final_invitations":0
   },
   "Guestlist":[
      {
         "GuestCode":"369AR",
         "all":2,
         "total_invitations":5430,
         "sent_invitations":5430,
         "final_invitations":0,
         "change":0,
         "accounts":0
      },
      {
         "GuestCode":"6POIA96TY",
         "all":2,
         "total_invitations":10000,
         "sent_invitations":10000,
         "final_invitations":0,
         "change":0,
         "accounts":0
      }
   ]
}

我的代码是:

package main

import (
    "encoding/json"
    "fmt"
    "log"
    "net/http"
)


type object struct {
    Success bool `json:"success"`
    Endpoint string `json:"endpoint"`
    Allguest struct {
        All int `json:"all"`
        Filtered int `json:"filtered"`
        TotalInvitations int `json:"total_invitations"`
        SentInvitations int `json:"sent_invitations"`
        FinalInvitations int `json:"final_invitations"`
    } `json:"Allguest"`
    Guestlist []struct {
        GuestCode string `json:"GuestCode"`
        All int `json:"all"`
        TotalInvitations int `json:"total_invitations"`
        SentInvitations int `json:"sent_invitations"`
        FinalInvitations int `json:"final_invitations"`
        Change int `json:"change"`
        Accounts int `json:"accounts"`
    } `json:"Guestlist"`
}

func main() {

uri := "https://siteurl.com/api?lists=1"
res, err := http.Get(uri)
fmt.Println(uri)
if err != nil {
fmt.Println("Error:", err)
    log.Fatal(err)
}
defer res.Body.Close()

 var s object
err := json.NewDecoder(res.Body).Decode(&s)
if err != nil {
    log.Fatal(err)
    fmt.Println("Error:", err)
}
fmt.Println(s.Success)
fmt.Println(s.Allguest.TotalInvitations)
for i := 0; i < 6; i++ {
fmt.Println(s.Guestlist[i].TotalInvitations)
)

}

问题是:

1. 如果响应为 null，则表示 index out of range error 我们如何避免这种情况？

2. 如果 TotalInvitations 值大于 100 则应用条件，然后保存在 100.csv 中，否则保存在 others 中。 .csv

Answer 1

如果您只需要 JSON 中的某些条目，您可以定义一个只包含您感兴趣的字段的结构。如果值可以为空，则最好在该结构中声明一个指针。请查看 go playground 中的示例:https://play.golang.org/p/mEwSXvPg3D