在Go中从REST API端点返回json对象

Question

我正在用golang构建API。我希望这个端点返回json数据，这样我就可以在我的前端使用它。

http.HandleFunc("/api/orders", createOrder)

目前我的函数不返回json对象和jsonMap变量不映射响应体到服务器的Create struc

我的结构

type CreateOrder struct {
Id     string  `json:"id"`
Status string  `json:"status"`
Links  []Links `json:"links"`
}

我的CreateOrder函数(根据注释更新)

func createOrder(w http.ResponseWriter, r *http.Request) {
accessToken := generateAccessToken()
w.Header().Set("Access-Control-Allow-Origin", "*")
fmt.Println(accessToken)
body := []byte(`{
"intent":"CAPTURE",
"purchase_units":[
{
"amount":{
"currency_code":"USD",
"value":"100.00"
}
}
]
}`)
req, err := http.NewRequest("POST", base+"/v2/checkout/orders", bytes.NewBuffer(body))
req.Header.Set("Content-Type", "application/json")
req.Header.Set("Authorization", "Bearer "+accessToken)
client := &http.Client{}
resp, err := client.Do(req)
if err != nil {
log.Fatalf("An Error Occured %v", err)
}
fmt.Println(resp.StatusCode)
defer resp.Body.Close()
if err != nil {
log.Fatal(err)
}
var jsonMap CreateOrder
error := json.NewDecoder(resp.Body).Decode(&jsonMap)
if error != nil {
log.Fatal(err)
}
w.WriteHeader(resp.StatusCode)
json.NewEncoder(w).Encode(jsonMap)
}

这是打印的内容。打印不包含对象键的值

{2MH36251C2958825N CREATED [{something self GET} {soemthing approve GET}]}

应该打印

{
id: '8BW01204PU5017303',
status: 'CREATED',
links: [
{
href: 'url here',
rel: 'self',
method: 'GET'
},
...
]
}

Answer 1

func createOrder(w http.ResponseWriter, r *http.Request) {
// ...
resp, err := http.DefaultClient.Do(req)
if err != nil {
log.Println("An Error Occured:", err)
return
}
defer resp.Body.Close()

if resp.StatusCode != http.StatusOK /* or http.StatusCreated (depends on the API you're using) */ {
log.Println("request failed with status:", http.Status)
w.WriteHeader(resp.StatusCode)
return
}
// decode response from external service
v := new(CreateOrder)
if err := json.NewDecoder(resp.Body).Decode(v); err != nil {
log.Println(err)
return
}

// send response to frontend
w.WriteHeader(resp.StatusCode)
if err := json.NewEncoder(w).Encode(v); err != nil {
log.Println(err)
}
}

或者，如果您希望将数据从外部服务原封不动地发送到前端，您应该能够这样做:

func createOrder(w http.ResponseWriter, r *http.Request) {
// ...
resp, err := http.DefaultClient.Do(req)
if err != nil {
log.Println("An Error Occured:", err)
return
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK /* or http.StatusCreated (depends on the API you're using) */ {
log.Println("request failed with status:", http.Status)
w.WriteHeader(resp.StatusCode)
return
}
// copy response from external to frontend
w.WriteHeader(resp.StatusCode)
if _, err := io.Copy(w, resp.Body); err != nil {
log.Println(err)
}
}