json - 如何从 Go http.Request 中检索对象？

Question

我有一个可以接收 HTTP GET 参数的工作应用。到目前为止，它们一直是字符串和整数，使用

http.Request.FormValue("field")

但现在我在参数中添加了一个简单对象数组，但我不知道如何将其转换为 Go 结构的 slice 。

有问题的数组是

mods:[{
    name : x,
    max : 1,
    min : 2
 },{
    name:y,...
 }]

所以我不确定如何继续将其映射到 Go 结构。我应该先创建结构并使用 JSON 映射 r.FormValue 的结果吗？

Answer 1

假设您要获取一组 github users并想要打印他们的昵称(api.github.com 中的Login 字段)。

给定一个用户数组示例:

[{
  "login": "simonjefford",
  "id": 136,
  "avatar_url": "https://avatars1.githubusercontent.com/u/136?v=3",
  "gravatar_id": "",
  "url": "https://api.github.com/users/simonjefford",
  "html_url": "https://github.com/simonjefford",
  "followers_url": "https://api.github.com/users/simonjefford/followers",
  "following_url": "https://api.github.com/users/simonjefford/following{/other_user}",
  "gists_url": "https://api.github.com/users/simonjefford/gists{/gist_id}",
  "starred_url": "https://api.github.com/users/simonjefford/starred{/owner}{/repo}",
  "subscriptions_url": "https://api.github.com/users/simonjefford/subscriptions",
  "organizations_url": "https://api.github.com/users/simonjefford/orgs",
  "repos_url": "https://api.github.com/users/simonjefford/repos",
  "events_url": "https://api.github.com/users/simonjefford/events{/privacy}",
  "received_events_url": "https://api.github.com/users/simonjefford/received_events",
  "type": "User",
  "site_admin": false
}]

你需要一个合适的结构来处理它:

type Users []struct {
  Login string `json:"login"`
  ID int `json:"id"`
  AvatarURL string `json:"avatar_url"`
  GravatarID string `json:"gravatar_id"`
  URL string `json:"url"`
  HTMLURL string `json:"html_url"`
  FollowersURL string `json:"followers_url"`
  FollowingURL string `json:"following_url"`
  GistsURL string `json:"gists_url"`
  StarredURL string `json:"starred_url"`
  SubscriptionsURL string `json:"subscriptions_url"`
  OrganizationsURL string `json:"organizations_url"`
  ReposURL string `json:"repos_url"`
  EventsURL string `json:"events_url"`
  ReceivedEventsURL string `json:"received_events_url"`
  Type string `json:"type"`
  SiteAdmin bool `json:"site_admin"`
}

我建议你使用json-to-go给定一个 json 有一个干净的结构。

然后您可以执行以下操作:

package main

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

func main() {

  response, err := http.Get("https://api.github.com/users?since=135")
  if err != nil {
     log.Fatal(err)
  } else {

    defer response.Body.Close()
    users := UnmarshalUsers(response)
    for _, u := range users {
        //Print each user's Login nickname
        fmt.Println(u.Login)
    }

  }

}

UnmarshalUsers 在哪里

func UnmarshalUsers(r *http.Response) Users {
    body, err := ioutil.ReadAll(r.Body)
    if err != nil {
        panic(err)
    }
    var users Users
    err = json.Unmarshal(body, &users)
    if err != nil {
        panic(err)
    }

    return users
}