Go-奇怪的JSON连字符解组错误

Question

I am having a very strange error while working with a json string. The problem was first introduced when I added a key-value pair of strings to the json input, which was "DeviceIdentifier": "device-id". I pared down my code to the minimum necessary to display the error. The error disappears when I change pretty much anything about the data in that key-value pair, which seems very strange to me. I can just use other keys to circumvent the error, but it seems like there is something I am missing here. Either that or there would seem to be something wrong with the library function... Any ideas?

package main

import (
    "encoding/json"
    "fmt"
)

type S struct {
    Name            string
    DeviceIdentifier []byte
}

func main() {
    var s S

    data := []byte(`{"Name": "test", "DeviceIdentifier": "device-id"}`)

    if err := json.Unmarshal(data, &s); err != nil {
        fmt.Println(err.Error())
    }
}

Go playground link: http://play.golang.org/p/huXuaokGik

Json package documentation: http://golang.org/pkg/encoding/json/

UPDATE

I just discovered that the encoding succeeds when the value string has a length that is divisible by 4, e.g. abcd and abcdefgh work, while abcde and abcdefg` do not.

Now that I know what base64 strings are the error makes a lot of sense. References here:

Wikipedia: http://en.wikipedia.org/wiki/Base64

Conversion tool: http://www.string-functions.com/base64encode.aspx

Answer 1

from the json package documentation :

Array and slice values encode as JSON arrays, except that []byte encodes as a base64-encoded string, and a nil slice encodes as the null JSON object.

so if you change your structure to DeviceIdentifier string it will work

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