如何在Go中设置自定义json响应结构

Question

I am importing "encoding/json" package to print output in json.I was able to get the json format but i want to modify the response structure. Here is the sample code

var people []Person
people = append(people, Person{Id: "1", Firstname: "John", Lastname: "Doe", Address: Address{City: "City X", State: "State X"}})
people = append(people, Person{Id: "2", Firstname: "Koko", Lastname: "Doe", Address: Address{City: "City Z", State: "State Y"}})
people = append(people, Person{Id: "3", Firstname: "Francis", Lastname: "Sunday"})
w.Header().Set("Content-Type", "application/json")
json.NewEncoder(w).Encode(people)

which outputs the following response

[
{
    "id": "1",
    "firstname": "John",
    "lastname": "Doe",
    "address": {
        "city": "City X",
        "state": "State X"
    }
},
{
    "id": "2",
    "firstname": "Koko",
    "lastname": "Doe",
    "address": {
        "city": "City Z",
        "state": "State Y"
    }
},
{
    "id": "3",
    "firstname": "Francis",
    "lastname": "Sunday",
    "address": {
        "city": "",
        "state": ""
    }
}
]

But i want to response into the following format

{
"status": "200",
"data": [
    {
        "id": "1",
        "firstname": "John",
        "lastname": "Doe",
        "address": {
            "city": "City X",
            "state": "State X"
        }
    },
    {
        "id": "2",
        "firstname": "Koko",
        "lastname": "Doe",
        "address": {
            "city": "City Z",
            "state": "State Y"
        }
    },
    {
        "id": "3",
        "firstname": "Francis",
        "lastname": "Sunday",
        "address": {
            "city": "",
            "state": ""
        }
    }
        ]
}

How can I modify the response format ? I am beginner in Go. Thanks for your help.

Answer 1

In order to change structure of your response, you need to provide the structure that you want to achieve with type.

You can define Response struct type which will consist of data and status fields:

type Response struct {
    Status string `json:"status"`
    Data []Person `json:"data"`
}

var people []Person
people = append(people, Person{Id: "1", Firstname: "John", Lastname: "Doe", Address: Address{City: "City X", State: "State X"}})
people = append(people, Person{Id: "2", Firstname: "Koko", Lastname: "Doe", Address: Address{City: "City Z", State: "State Y"}})
people = append(people, Person{Id: "3", Firstname: "Francis", Lastname: "Sunday"})
w.Header().Set("Content-Type", "application/json")

resp := Response{Status: "200", Data: people}
json.NewEncoder(w).Encode(resp)