执行UnmarshalExtJSON时无效的读取数组请求

Question

I'm trying to unmarshal extended JSON into a struct using UnmarshalExtJSON from go.mongodb.org/mongo-driver/bson

It's giving me an error: invalid request to read array

How can I unmarshal this data into my struct?

MVCE:

package main

import (
    "fmt"

    "go.mongodb.org/mongo-driver/bson"
)

func main() {
    var json = "{\"data\":{\"streamInformation\":{\"codecs\":[\"avc1.640028\"]}}}"
    var workflow Workflow
    e := bson.UnmarshalExtJSON([]byte(json), false, &workflow)
    if e != nil {
        fmt.Println("err is ", e)
        // should print "err is  invalid request to read array"
        return
    }
    fmt.Println(workflow)
}

type Workflow struct {
    Data WorkflowData `json:"data,omitempty"`
}

type WorkflowData struct {
    StreamInformation StreamInformation `json:"streamInformation,omitempty"`
}

type StreamInformation struct {
    Codecs []string `json:"codecs,omitempty"`
}

I'm using go version 1.12.4 windows/amd64

Answer 1

You're unmarshalling using the bson package, but you're using json struct field tags. Change them to bson struct field tags and it should work for you:

package main

import (
    "fmt"

    "go.mongodb.org/mongo-driver/bson"
)

func main() {
    var json = "{\"data\":{\"streamInformation\":{\"codecs\":[\"avc1.640028\"]}}}"
    var workflow Workflow
    e := bson.UnmarshalExtJSON([]byte(json), false, &workflow)
    if e != nil {
        fmt.Println("err is ", e)
        return
    }
    fmt.Println(workflow)
}

type Workflow struct {
    Data WorkflowData `bson:"data,omitempty"`
}

type WorkflowData struct {
    StreamInformation StreamInformation `bson:"streamInformation,omitempty"`
}

type StreamInformation struct {
    Codecs []string `bson:"codecs,omitempty"`
}

with output:

paul@mac:bson$ ./bson
{{{[avc1.640028]}}}
paul@mac:bson$