json解码/解组无法在json中按预期工作

Question

I have an authentication payload that I need to decode to obtain some tokens in a webapp:

{
    "access_token": "eyJhbGciOiJSUzI1NiIsInR5cCIgOiAiSldUIiwia2lkIiA6ICJzUG9sQmV3Z2ZBMGxHbFdzTnZLNEVndGJ1WHhnOU90dVhXeFRVbWhKeF9NIn0.eyJqdGkiOiJkMjAzOWQ0ZC00NjEwLTQ2ZmMtYjE5NC03Nzc4YWJhZGE1YmYiLCJleHAiOjE1NDkyOTQyMjUsIm5iZiI6MCwiaWF0IjoxNTQ5MjkzOTI1LCJpc3MiOiJodHRwOi8vMTkyLjE2OC45OS4xMDA6OTAvYXV0aC9yZWFsbXMvc2FtcGxlc2hvcCIsImF1ZCI6ImFjY291bnQiLCJzdWIiOiJkYWU0NjE1OC03ZjQ2LTQ0N2UtOGZmMC0xNWIxNzEyZGY1NWIiLCJ0eXAiOiJCZWFyZXIiLCJhenAiOiJmcm9udGVuZCIsImF1dGhfdGltZSI6MTU0OTI5MzkyNSwic2Vzc2lvbl9zdGF0ZSI6IjY2YjNkNjJkLWIzYzYtNDJiYi04Njc5LWYwZGVkMGU3ODk1NyIsImFjciI6IjEiLCJyZWFsbV9hY2Nlc3MiOnsicm9sZXMiOlsib2ZmbGluZV9hY2Nlc3MiLCJ1bWFfYXV0aG9yaXphdGlvbiJdfSwicmVzb3VyY2VfYWNjZXNzIjp7ImFjY291bnQiOnsicm9sZXMiOlsibWFuYWdlLWFjY291bnQiLCJ2aWV3LXByb2ZpbGUiXX19LCJzY29wZSI6Im9wZW5pZCBlbWFpbCBwcm9maWxlIiwiZW1haWxfdmVyaWZpZWQiOmZhbHNlLCJuYW1lIjoidGVzdGVyIHRlc3RlciIsInByZWZlcnJlZF91c2VybmFtZSI6InRlc3RlckB0ZXN0ZXIuY29tIiwiZ2l2ZW5fbmFtZSI6InRlc3RlciIsImZhbWlseV9uYW1lIjoidGVzdGVyIiwiZW1haWwiOiJ0ZXN0ZXJAdGVzdGVyLmNvbSJ9.A8mdTXpANdTn_n3k-6peoIy2p9RmAakA7hxF0aTtCYk_FrpP8GC4Eg4sE2TgSzSzKGSVbEbp3zJkT6v8MVPv721rqYir99uJ-gLv48P83WFEAu93Gf315CSXBi4wSsph-vahOhI75BwPYteZdD9CJJUnbt53fuxfwjimJZW9zqyWBc8CZZ--7oxScgXJb8rJEMFlm4uA0WOCPw9TelPBZE7wxmyaibU6DKZqQlKsC14wPFi8-URGhL2ZG2n21kz58nsLcRiBLiGAwDSWakKuFTWgc6M_Pfu8tF6mQ2FWWMHwIN8aOc_OZ6gvyFsdY0v2BxRd1Agta8KopM3IpMsa6w",
    "expires_in": 299,
    "refresh_expires_in": 1799,
    "refresh_token": "eyJhbGciOiJIUzI1NiIsInR5cCIgOiAiSldUIiwia2lkIiA6ICJlM2ZmYTkxZi05NGJiLTQzMWMtYWY4YS05MTgyMmU1MjBjZWMifQ.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.XCvoZnyrVeGGF4iORaQ_1BAlKyma9B0DENw1n1E6I_8",
    "token_type": "bearer",
    "id_token": "eyJhbGciOiJSUzI1NiIsInR5cCIgOiAiSldUIiwia2lkIiA6ICJzUG9sQmV3Z2ZBMGxHbFdzTnZLNEVndGJ1WHhnOU90dVhXeFRVbWhKeF9NIn0.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.kKIpxriAXWiySz9xOmr_XHmMgz7_L0q-qgt0WHb8yFRSdrPFePRqoe_RKnxtxwn6nIGOYbY78djr9GMtMpAcJquumpHpo3RGG1o5Y088rft4A7NNvUwDJeZhx6DkeVq5FfL0hvNfUntfUvtQaaVYh4M6TjJo6nakyJ1ZSyrRwSZZmNXzd0S4XY3oV19DOiyrLl3qBxhgw33pLYla5dIAs_KnrGVmLSpNJT61T810kqN-dT1c4EFMZ1iz7Bfh4RucK4oHGZmPlR3znqMMijirK8QT7ukTJvhG-TlmfsBMe0r_9UjdQ9wxjZ7pDi7pfYKVOv55O9Lzk2PbAjIHe3UKiA",
    "not-before-policy": 1549293916,
    "session_state": "66b3d62d-b3c6-42bb-8679-f0ded0e78957",
    "scope": "openid email profile"
}

The struct I am using is as follow:

type Token struct {
    AccessToken  string    `json:"access_token"`
    TokenType    string    `json:"token_type"`
    RefreshToken string    `json:"refresh_token"`
    Expiry       time.Time `json:"expires_in"`
}

After decoding the response, I tried printing the response :

var authToken Token
json.Unmarshal(response.Body, &authToken)

        fmt.Println("-------------------- accessToken " + authToken.AccessToken)
        fmt.Println("-------------------- refreshToken " + authToken.RefreshToken)
        fmt.Println("-------------------- expires ", authToken.Expiry)
        fmt.Println("--------------------  type " + authToken.TokenType)

Only the first one AccessToken has a value, everything else is empty.

I also tried using json.NewDecoder(response.Body).Decode(&authToken)

Same result.

Is there anything wrong with my approach ?

Answer 1

You have to check error from json.Unmarshal or from decoder.Decode.
And "expires_in": 299, it is not time, it is int.

code:

package main

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

type Token struct {
  AccessToken  string    `json:"access_token"`
  TokenType    string    `json:"token_type"`
  RefreshToken string    `json:"refresh_token"`
  Expiry       int       `json:"expires_in"`
}

func main() {
  http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
    decoder := json.NewDecoder(r.Body)
    var authToken Token
    if err := decoder.Decode(&authToken); err != nil {
      fmt.Fprintf(w, "error: %s", err)
      return
    }

    fmt.Println("-------------------- accessToken " + authToken.AccessToken)
    fmt.Println("-------------------- refreshToken " + authToken.RefreshToken)
    fmt.Println("-------------------- expires ", authToken.Expiry)
    fmt.Println("--------------------  type " + authToken.TokenType)
  })

  http.ListenAndServe(":8000", nil)
}

curl:

curl -XPOST 'http://localhost:8000' -H 'Content-Type: application/json' -d '{
  "access_token": "at",
  "refresh_token": "rt",
  "expires_in": 299,
  "token_type": "bearer"
}'

result:

-------------------- accessToken at
-------------------- refreshToken rt
-------------------- expires  299
--------------------  type bearer