Post封送JSON数据作为URL编码表单数据

Question

我正试图通过将认证结构转换为application/x-www-form-urlencoded数据来发送POST请求。

package main
import (
"bytes"
"encoding/json"
"io/ioutil"
"log"
"net/http"
)
type Payload struct {
Username string `json:"username"`
Password string `json:"password"`
GrantType string `json:"grant_type"`
Scope string `json:"scope"`
}
func main() {
var endpoint string = "https://api.io/v1/oauth/token"
jsonPay := &Payload{
Username: "email",
Password: "pass",
GrantType: "password",
Scope: "SPACE SEPARATED STRINGS",
}
//byteArr, err := json.Marshal(jsonPay)
//if err != nil {
//    log.Printf("Unable to map structuren%v", err)
//}
payloadBuf := new(bytes.Buffer)
json.NewEncoder(payloadBuf).Encode(jsonPay)
req, err := http.NewRequest("POST", endpoint, payloadBuf)
if err != nil {
log.Fatal(err)
}
req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
req.Header.Add("Accept", "application/json")
resp, err := http.DefaultClient.Do(req)
if err != nil {
log.Fatal(err)
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
if err != nil {
log.Fatal(err)
}
log.Printf(string(body))
}

我试过:

1. 发送JSON编码的有效负载缓冲区，返回

   {"error":"invalid_request","error_description":"Missing grant type"}
   

2. 对封送JSON对象使用bytes.NewReader，它也返回

   {"error":"invalid_request","error_description":"Missing grant type"}
   

3. 使用strings.NewReader与JSON编码的有效负载缓冲区，返回

   cannot use payloadBuf (variable of type *bytes.Buffer) as type string in argument to strings.NewReader
   

curl请求如下:

curl --request POST 
--url https://api.io/v1/oauth/token 
--header 'Content-Type: application/x-www-form-urlencoded' 
--data 'username=email' 
--data 'password=pass' 
--data 'grant_type=password' 
--data 'scope=SPACE SEPARATED STRINGS'

和

一起使用

package main
import (
"io/ioutil"
"log"
"net/http"
"net/url"
"strings"
)
func main() {
const endpoint string = "https://api.io/v1/oauth/token"
payload := url.Values{
"username":   {"email"},
"password":   {"pass"},
"grant_type": {"password"},
"scope":      {"SPACE SEPARATED STRINGS"},
}
req, err := http.NewRequest("POST", endpoint, strings.NewReader(payload.Encode()))
if err != nil {
log.Printf("Unable to perform POST request:n%v", err)
}
req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
req.Header.Add("Accept", "application/json")
resp, err := http.DefaultClient.Do(req)
if err != nil {
log.Fatal(err)
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
if err != nil {
log.Fatal(err)
}
log.Println(string(body))
}

如何将封送JSON数据发布为application/x-www-form-urlencoded

Answer 1

执行@RedBlue的建议:

package main
import (
"io/ioutil"
"log"
"net/http"
"strings"
"net/url"
)
type Payload struct {
Username string `json:"username"`
Password string `json:"password"`
GrantType string `json:"grant_type"`
Scope string `json:"scope"`
}
func main() {
const endpoint string = "https://api.io/v1/oauth/token"
formData := &Payload{
Username: "email",
Password: "pass",
GrantType: "password",
Scope: "SPACE SEPARATED STRINGS",
}
payload := url.Values{
"username":   {formData.Username},
"password":   {formData.Password},
"grant_type": {formData.GrantType},
"scope":      {formData.Scope},
}
req, err := http.NewRequest("POST", endpoint, strings.NewReader(payload.Encode()))
if err != nil {
log.Printf("Unable to perform POST request:n%v", err)
}
req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
req.Header.Add("Accept", "application/json")
resp, err := http.DefaultClient.Do(req)
if err != nil {
log.Fatal(err)
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
if err != nil {
log.Fatal(err)
}
log.Println(string(body))
}