为什么解组这个 API 响应 return 一个意外的 EOF？

Question

问题

我正在使用协议缓冲区和 gRPC 在 Go 中创建一个微服务。它与第三方 API (Snooth) 交互，我正在尝试使用 proto 包将 JSON 响应解组到我创建的 protobuf 结构中。

解组 returns 一个 unexpected EOF 错误。

我试过的

使用 json.newDecoder 代替 json.unmarshal
jsonpb.Unmarshal 而不是 proto.Unmarshal（returns 一个 bad value in StructValue for key 错误）
使用 io.LimitReader

我还读过一些关于在原型类型前加上尺寸标签之类的东西？但我不确定那是什么或者它是否相关。这是 Github.

上的回购协议

问题

导致此 unexpected EOF 错误的原因是什么？我该如何修复它，以便 API 响应成功解组到原型结构中？

旁注：我是 Go 的新手，也非常感谢以下代码中的任何 feedback/improvements。谢谢！

代码

Proto

message Response {
    message Meta {
        int32 results = 1;
        int32 returned = 2;
        string errmsg = 3;
        int32 status = 4;
    }

    Meta meta = 1;
    repeated google.protobuf.Struct wines = 2;
    repeated google.protobuf.Struct actions = 3;
}

main.go

func fetchFromSnooth(e string, qs string, c chan response) {
    defer func() {
        if r := recover(); r != nil {
            log.Printf("Error fetching from Snooth: %s", r)
            errmsg := fmt.Sprint(r)
            c <- response{nil, snoothApiError{errmsg}}
        }
    }()

    v := url.Values{"akey": {os.Getenv("SNOOTH_API_KEY")}}
    requestUrl := fmt.Sprintf("%s%s/?%s%s", snoothRoot, e, v.Encode(), qs)
    log.Printf("Fetching: %s", requestUrl)

    res, err := httpClient.Get(requestUrl)
    if err != nil {
        panic(err)
    }
    defer res.Body.Close()

    body, err := ioutil.ReadAll(res.Body)
    if err != nil {
        panic(err)
    }

    result := &pb.Response{}
    if err := proto.Unmarshal(body, result); err != nil {
        panic(err)
    }
    c <- response{result, snoothApiError{""}}
}

func (s *snoothApiService) searchWines(params *pb.Parameters_WineSearch) response {
    c := make(chan response)
    defer close(c)

    v := url.Values{}
    go fetchFromSnooth("wines", v.Encode(), c)
    return <-c
}

func main() {
    snooth := snoothApiService{}
    resp := snooth.searchWines(nil)
    fmt.Println(resp)
}

编辑

这是我尝试解组的 API 响应类型的示例：

    {
    "meta": {
        "results": 1489442,
        "returned": 5,
        "errmsg": "",
        "status": 1
    },
    "wines": [
        {
            "name": "Conway Deep Sea Chardonnay la Costa Wine Co",
            "code": "conway-deep-sea-chardonnay-la-costa-wine-co-2008-1",
            "region": "USA > California > Central Coast",
            "winery": "Conway Family Wines",
            "winery_id": "conway-family-wines",
            "varietal": "Chardonnay",
            "price": "21.99",
            "vintage": "2008",
            "type": "White Wine",
            "link": "http:\/\/www.snooth.com\/wine\/conway-deep-sea-chardonnay-la-costa-wine-co-2008-1\/",
            "tags": "",
            "image": "https:\/\/ei.isnooth.com\/multimedia\/0\/2\/8\/image_787698_square.jpeg",
            "snoothrank": 3,
            "available": 0,
            "num_merchants": 0,
            "num_reviews": 10
        },
        {
            "name": "Olmaia Cabernet di Toscana",
            "code": "olmaia-cabernet-di-toscana",
            "region": "Italy > Tuscany > Toscana Igt",
            "winery": "Col D Orcia",
            "winery_id": "col-d-orcia",
            "varietal": "Cabernet Sauvignon",
            "price": "0.00",
            "vintage": "",
            "type": "Red Wine",
            "link": "http:\/\/www.snooth.com\/wine\/olmaia-cabernet-di-toscana\/",
            "tags": "",
            "image": "https:\/\/ei.isnooth.com\/multimedia\/d\/e\/e\/image_790198_square.jpeg",
            "snoothrank": 3.5,
            "available": 0,
            "num_merchants": 0,
            "num_reviews": 25
        },
        {
            "name": "Dominio Dostares Prieto Picudo Vino de la Tierra de Castilla Y León Cumal",
            "code": "dominio-dostares-prieto-picudo-vino-de-la-tierra-de-castilla-y-leon-cumal-2006",
            "region": "Spain > Castilla y León > Vino de la Tierra de Castilla y León",
            "winery": "Bischöfliches Priesterseminar Trier",
            "winery_id": "bischofliches-priesterseminar-trier",
            "varietal": "Prieto Picudo",
            "price": "15.89",
            "vintage": "2006",
            "type": "Red Wine",
            "link": "http:\/\/www.snooth.com\/wine\/dominio-dostares-prieto-picudo-vino-de-la-tierra-de-castilla-y-leon-cumal-2006\/",
            "tags": "",
            "image": "https:\/\/ei.isnooth.com\/multimedia\/d\/0\/4\/image_336595_square.jpeg",
            "snoothrank": "n\/a",
            "available": 0,
            "num_merchants": 0,
            "num_reviews": 1
        },
        {
            "name": "Dominio Dostares Prieto Picudo Vino de la Tierra de Castilla Y León Cumal",
            "code": "dominio-dostares-prieto-picudo-vino-de-la-tierra-de-castilla-y-leon-cumal-2005",
            "region": "Spain > Castilla y León > Vino de la Tierra de Castilla y León",
            "winery": "Bischöfliches Priesterseminar Trier",
            "winery_id": "bischofliches-priesterseminar-trier",
            "varietal": "Prieto Picudo",
            "price": "38.99",
            "vintage": "2005",
            "type": "Red Wine",
            "link": "http:\/\/www.snooth.com\/wine\/dominio-dostares-prieto-picudo-vino-de-la-tierra-de-castilla-y-leon-cumal-2005\/",
            "tags": "",
            "image": "https:\/\/ei.isnooth.com\/multimedia\/1\/d\/a\/image_336596_square.jpeg",
            "snoothrank": "n\/a",
            "available": 0,
            "num_merchants": 0,
            "num_reviews": 1
        },
        {
            "name": "The Little Penguin Chardonnay Premier",
            "code": "the-little-penguin-chardonnay-premier-2010",
            "region": "South East Australia",
            "winery": "The Little Penguin",
            "winery_id": "the-little-penguin",
            "varietal": "Chardonnay",
            "price": "11.99",
            "vintage": "2010",
            "type": "White Wine",
            "link": "http:\/\/www.snooth.com\/wine\/the-little-penguin-chardonnay-premier-2010\/",
            "tags": "",
            "image": "https:\/\/ei.isnooth.com\/multimedia\/2\/c\/4\/image_826282_square.jpeg",
            "snoothrank": "n\/a",
            "available": 0,
            "num_merchants": 0,
            "num_reviews": 7
        }
    ]
}

Answer 1

它确实用 encoding/json 包解析：https://play.golang.org/p/IQzMm2tDI7w

protoc 生成的代码的 Unmarshal 解析 Protocol Buffers 编码的字节流，而不是 JSON!

Answer 2

--更新--

我现在已经根据需要使用 jsonpb.Unmarshal 方法对响应进行了解组。为此，尽管我必须首先使用常规 json 库解组和编组响应，以便在响应中绕过一些转义值（我收到了 'bad value in Struct' 错误：

resJson, err := ioutil.ReadAll(res.Body)

j := make(map[string]interface{})
if err := json.Unmarshal(resJson, &j); err != nil {
    panic(err)
}

jbytes, err := json.Marshal(j)

result := &pb.Response{}
r := strings.NewReader(string(jbytes))
if err := jsonpb.Unmarshal(r, result); err != nil {
    panic(err)
}

为什么解组这个 API 响应 return 一个意外的 EOF？

Why does unmarshalling this API response return an unexpected EOF?

go

protocol-buffers

grpc

问题

我试过的

问题

代码

编辑

--更新--