在 Go 中部分 JSON 解组为地图 [英] Partly JSON unmarshal into a map in Go

问题描述

我的 websocket 服务器将接收和解组 JSON 数据.此数据将始终包含在具有键/值对的对象中.key-string 将作为值标识符，告诉 Go 服务器它是什么类型的值.通过知道什么类型的值，我可以继续使用 JSON 将值解组为正确的结构类型.

My websocket server will receive and unmarshal JSON data. This data will always be wrapped in an object with key/value pairs. The key-string will act as value identifier, telling the Go server what kind of value it is. By knowing what type of value, I can then proceed to JSON unmarshal the value into the correct type of struct.

每个 json-object 可能包含多个键/值对.

Each json-object might contain multiple key/value pairs.

示例 JSON:

{
    "sendMsg":{"user":"ANisus","msg":"Trying to send a message"},
    "say":"Hello"
}

有没有什么简单的方法可以使用 "encoding/json" 包来做到这一点?

Is there any easy way using the "encoding/json" package to do this?

package main

import (
    "encoding/json"
    "fmt"
)

// the struct for the value of a "sendMsg"-command
type sendMsg struct {
    user string
    msg  string
}
// The type for the value of a "say"-command
type say string

func main(){
    data := []byte(`{"sendMsg":{"user":"ANisus","msg":"Trying to send a message"},"say":"Hello"}`)

    // This won't work because json.MapObject([]byte) doesn't exist
    objmap, err := json.MapObject(data)

    // This is what I wish the objmap to contain
    //var objmap = map[string][]byte {
    //  "sendMsg": []byte(`{"user":"ANisus","msg":"Trying to send a message"}`),
    //  "say": []byte(`"hello"`),
    //}
    fmt.Printf("%v", objmap)
}

感谢您的任何建议/帮助！

Thanks for any kind of suggestion/help!

推荐答案

这可以通过解组为 map[string]json.RawMessage 来实现.

This can be accomplished by Unmarshaling into a map[string]json.RawMessage.

var objmap map[string]json.RawMessage
err := json.Unmarshal(data, &objmap)

要进一步解析sendMsg，您可以执行以下操作:

To further parse sendMsg, you could then do something like:

var s sendMsg
err = json.Unmarshal(objmap["sendMsg"], &s)

对于say，你可以做同样的事情并解组成一个字符串:

For say, you can do the same thing and unmarshal into a string:

var str string
err = json.Unmarshal(objmap["say"], &str)

<小时>

请记住，您还需要导出 sendMsg 结构中的变量以正确解组.所以你的结构定义是:

---

Keep in mind you will also need to export the variables in your sendMsg struct to unmarshal correctly. So your struct definition would be:

type sendMsg struct {
    User string
    Msg  string
}

示例:https://play.golang.org/p/OrIjvqIsi4-

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