Convert string having json to json or struct - json

Question

I am getting this type of response from an API:
{
"ok": true,
"response": "[
{
"Id": 163,
"Name": "Availability",
"Path": "Performance|Tier1",
"frequency": "ONE_MIN",
"Values": [
{
"startTimeInMillis": 1571314200000,
"occurrences": 1,
"current": 1,
"min": 0,
"max": 0,
"useRange": false,
"count": 1,
"sum": 1,
"value": 1,
"standardDeviation": 0
},
{
"startTimeInMillis": 1571314260000,
"occurrences": 1,
"current": 1,
"min": 0,
"max": 0,
"useRange": false,
"count": 1,
"sum": 1,
"value": 1,
"standardDeviation": 0
},
}
]
}
]
}
I want to convert this into time series format. To do so first I am trying to unmarshal the response to this struct:
type App struct{
ID string `json:"metric_id"`
Name string `json:"metric_name"`
Path string `json:"metric_path"`
Frequency string `json:"frequency"`
Values []string `json:"metric_values"`
}
I am doing this:
apprsp := App{}
fmt.Println(json.Unmarshal([]byte(ame.Response), &apprsp))
But I am getting error while json.Unmarshal.
What I am trying to do is to generate a json of format:
{'time':'value','time1':'value2'}
Where time/time1 and value/value2 is startTimeInMillis and value from values array.
What I am doing wrong while json unmarshal? What should be done to unmarshal the above data?

Answer 1

Your App structure is not even closely related to the json document you're trying to unmarshal. To unmarshal a json document, you have to have a Go structure that somewhat matches the structure of the underlying document.
type ResponseValue struct {
StartTime int64 `json:"startTimeMillis"`
// other elements of Values here, if you're interested in them
}
type Response struct {
Id int `json:"Id"`
Name string `json:"Name"`
Path string `json:"Path"`
Frequency string `json:"frequency"`
Values []ResponseValue `json:"Values"`
}
type Body struct {
Response []Response `json:"response"`
}
var data Body
json.Unmarshal([]byte(ame.Response),&data)
Then, you can extract the time series from data.

Answer 2

As the one above me just said your mapping from your json to the struct is wrong.
An easy way to find the write mapping is to use this tool https://mholt.github.io/json-to-go/
It enables you to map json to an auto generated struct.
here is your response struct
type Response struct {
ID int `json:"Id"`
Name string `json:"Name"`
Path string `json:"Path"`
Frequency string `json:"frequency"`
Values []struct {
StartTimeInMillis int64 `json:"startTimeInMillis"`
Occurrences int `json:"occurrences"`
Current int `json:"current"`
Min int `json:"min"`
Max int `json:"max"`
UseRange bool `json:"useRange"`
Count int `json:"count"`
Sum int `json:"sum"`
Value int `json:"value"`
StandardDeviation int `json:"standardDeviation"`
} `json:"Values"`
}