问题

我正在使用 Protocol Buffer 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 响应解码为我创建的 protobuf 结构。

解码返回一个意外的 EOF 错误。

我尝试过的

• 使用 json.newDecoder 而不是 json.unmarshal
• jsonpb.Unmarshal 而不是 proto.Unmarshal(返回 StructValue 中键的错误值 错误)
• 使用 io.LimitReader 限制响应读取

我还读过一些关于在原型(prototype)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 repo 协议(protocol).

问题

是什么导致了这个意外的 EOF 错误，我该如何解决它，以便 API 响应成功解码到原型(prototype)结构中？

旁注:我是 Go 的新手，也非常感谢对以下代码的任何反馈/改进。谢谢!

代码

原型(prototype)

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

这是我尝试解码的 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
        }
    ]
}

最佳答案

它确实使用 encoding/json 包进行解析:https://play.golang.org/p/IQzMm2tDI7w

protoc 生成的代码的 Unmarshal 解析一个 Protocol Buffers 编码的字节流，而不是 JSON!

关于go - 为什么解码此 API 响应会返回意外的 EOF？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/50314476/