Can get value of JSON in Go - json

Question

I'm new in Go. I'm trying to read a JSON file and get a part of it for then operate with the values obtained.
My JSON is in the file example.json:
{"results":[{"statement_id":0,"series":[{"name":"cpu/node_utilization","columns":["time","distinct"],"values":[[10,1],[11,3],[13,5]]}]}]}
So what I would like to get is the "values" for get the sum of all the elements. In this case: 1+3+5
Here is the code that I have. I'm available to get the results, but then I don't manage to get series.
Here is the code that I have:
package main
import (
"encoding/json"
"fmt"
"io/ioutil"
"os"
)
func main() {
// Open our jsonFile
jsonFile, err := os.Open("example.json")
// if we os.Open returns an error then handle it
if err != nil {
fmt.Println(err)
}
fmt.Println("Successfully Opened example.json")
// defer the closing of our jsonFile so that we can parse it later on
defer jsonFile.Close()
byteValue, _ := ioutil.ReadAll(jsonFile)
var all_data map[string]interface{}
json.Unmarshal([]byte(byteValue), &all_data)
fmt.Println(all_data["results"])
}
I've tried diferent solutions like
all_data["results"].(map[string]interface{})["series"])
But the problem is that the map is in an array, and I don't know how to solve it.

Answer 1

Using interfaces and map
package main
import (
"encoding/json"
"fmt"
)
func main() {
byteValue := []byte(`{"results":[{"statement_id":0,"series":[{"name":"cpu/node_utilization","columns":["time","distinct"],"values":[[10,1],[11,3],[13,5]]}]}]}`)
var all_data map[string][]interface{}
json.Unmarshal([]byte(byteValue), &all_data)
fmt.Println("result:", all_data["results"])
for _, r := range all_data["results"] {
s := r.(map[string]interface{})
fmt.Println("series:", s["series"])
w := s["series"].([]interface{})
for _, x := range w {
y := x.(map[string]interface{})
fmt.Println(y)
z := y["values"].([]interface{})
fmt.Println("values:", z)
for _, v := range z {
u := v.([]interface{})
fmt.Println(u)
for _, i := range u {
val := i.(float64)
fmt.Println(val)
}
}
}
}
}

Answer 2

I have solved defining an Struct.
package main
import (
"encoding/json"
"fmt"
"io/ioutil"
"os"
)
type AutoGenerated struct {
Results []struct {
StatementID int `json:"statement_id"`
Series []struct {
Name string `json:"name"`
Columns []string `json:"columns"`
Values [][]int `json:"values"`
} `json:"series"`
} `json:"results"`
}
func main() {
// Open our jsonFile
jsonFile, err := os.Open("example.json")
// if we os.Open returns an error then handle it
if err != nil {
fmt.Println(err)
}
fmt.Println("Successfully Opened example.json")
// defer the closing of our jsonFile so that we can parse it later on
defer jsonFile.Close()
byteValue, _ := ioutil.ReadAll(jsonFile)
all_data := AutoGenerated{}
json.Unmarshal([]byte(byteValue), &all_data)
fmt.Println(all_data.Results[0].Series[0].Values)
}
I have used this web to generate automatically the Struct providing the JSON structure