Help in unmarshalling json

Getting Help
7

Let’s assume you have input data with your json as a variable:

// Cleaned up JSON from your example
exampleJSON := []byte(`{
    "BSR Address": "10.0.3.5",
    "228.0.0.0/8": {
        "10.0.3.5": {
            "Rp Address": "10.0.3.5",
            "Rp HoldTime": 65535,
            "Rp Priority": 1,
            "Hash Val": 840583365
        },
        "Pending RP count": 100
    }
}`)

You can unmarshal that into a map[string]interface{} just fine:

func main() {
	// Unmarshal to generic type
	var dat map[string]interface{}
	if err := json.Unmarshal(exampleJSON, &dat); err != nil {
		panic(err)
	}

	fmt.Println("Printing key value pairs")
	for k, v := range dat {
		fmt.Println(k, ":", v)
	}
}

OUTPUT:

Printing key value pairs
BSR Address : 10.0.3.5
228.0.0.0/8 : map[10.0.3.5:map[Hash Val:8.40583365e+08 Rp Address:10.0.3.5 Rp HoldTime:65535 Rp Priority:1] Pending RP count:100]

When you say “I need the key values and the struct values, but internal map[string]struct does not get unmarshaled properly.”, I believe what you mean is “I want to be able to access the child maps and values from my code”, which is a simple matter of type assertion. Let’s update the example above to call a function that uses reflection to assert types on child maps and print them:

func main() {
	// Unmarshal to generic type
	var dat map[string]interface{}
	if err := json.Unmarshal(exampleJSON, &dat); err != nil {
		panic(err)
	}
	fmt.Println("Being more clever and using reflection to print values")
	printValues("", dat)
}

func printValues(prefix string, values map[string]interface{}) {
	for k, v := range values {
		// If our value is itself a map, recursively print its values
		if reflect.ValueOf(v).Kind() == reflect.Map {
			fmt.Println(prefix, k, ":")
			printValues(prefix+"\t", v.(map[string]interface{}))
		} else {
			// Otherwise, just print the key/value pair along with prefix
			fmt.Println(prefix, k, ":", v)
		}
	}
}

This will get you the following:

 Being more clever and using reflection to print values
 BSR Address : 10.0.3.5
 228.0.0.0/8 :
	 10.0.3.5 :
		 Rp Address : 10.0.3.5
		 Rp HoldTime : 65535
		 Rp Priority : 1
		 Hash Val : 8.40583365e+08
	 Pending RP count : 100

Here’s a go playground link I created for you where you can run this for yourself:

https://go.dev/play/p/1wqxTok7TIP

Try changing the hard-coded json and see what happens. Also be sure to check this excellent StackOverflow question and associated answers for other approaches. If that doesn’t get you where you need to go, I think you’re going to have to provide more example code and what you’re trying to accomplish.