如何在Golang中访问嵌套的Json键值

Question

Team, new to Programming. I have data available after unmarshaling the Json as shown below, which has nested Key values. flat key values I am able to access, how do I access nested key values. Here is the byte slice data shown below after unmarshaling —>

tables:[map[name:basic__snatpool_members] map[name:net__snatpool_members] map[name:optimizations__hosts] map[columnNames:[name] name:pool__hosts rows:[map[row:[ry.hj.com]]]] traffic_group:/Common/traffic-group-1

Flat key values I am able to access by using the following code

p.TrafficGroup = m[“traffic_group”].(string)

here is the complete function

func dataToIapp(name string, d *schema.ResourceData) bigip.Iapp {
        var p bigip.Iapp

        var obj interface{}

        jsonblob := []byte(d.Get("jsonfile").(string))
        err := json.Unmarshal(jsonblob, &obj)
        if err != nil {
                fmt.Println("error", err)
        }
        m := obj.(map[string]interface{}) // Important: to access property
        p.Name = m[“name”].(string)
        p.Partition = m[“partition”].(string)

        p.InheritedDevicegroup = m[“inherited_devicegroup”].(string)

}

Answer 1

Note: This may not work with your JSON structure. I inferred what it would be based on your question but without the actual structure, I cannot guarantee this to work without modification.

If you want to access them in a map, you need to assert that the interface pulled from the first map is actually a map. So you would need to do this:

tmp := m["tables"]
tables, ok := tmp.(map[string]string)
if !ok {
    //error handling here
}

r.Name = tables["name"].(string)

But instead of accessing the unmarshaled JSON as a map[string]interface{}, why don't you create structs that match your JSON output?

type JSONRoot struct {
    Name string `json:"name"`
    Partition string `json:"partition"`
    InheritedDevicegroup string `json:"inherited_devicegroup"`
    Tables map[string]string `json:"tables"` //Ideally, this would be a map of structs
}

Then in your code:

func dataToIapp(name string, d *schema.ResourceData) bigip.Iapp {
    var p bigip.Iapp

    var obj &JSONRoot{}

    jsonblob := []byte(d.Get("jsonfile").(string))
    err := json.Unmarshal(jsonblob, &obj)
    if err != nil {
            fmt.Println("error", err)
    }

    p.Name = obj.Name
    p.Partition = obj.Partition

    p.InheritedDevicegroup = obj.InheritedDevicegroup

    p.Name = obj.Tables["name"]
}