2

我已经实现了以下代码，用于在 Go 中重试 http post 请求。

在第二次重试中，我总是将请求正文设为空。我试过 defer req.body.close() 但它不起作用。谁能帮我解决这个问题？

func httpRetry(req *http.Request, timeOut time.Duration, retryAttempts int, retryDelay time.Duration) (*http.Response, error) {

    attempts := 0

    for {
        attempts++
        fmt.Println("Attempt - ", attempts)
        statusCode := 0

        tr := &http.Transport{
            TLSClientConfig: &tls.Config{InsecureSkipVerify: true},
        }
        var netClient = &http.Client{
            Timeout:   time.Second * timeOut,
            Transport: tr,
        }
        fmt.Println("ret 88888 ", req)
        response, err := netClient.Do(req)

        //defer req.Body.Close()

        fmt.Println(response, "  dd", err)

        if response != nil {
            fmt.Println(response.StatusCode)
            statusCode = response.StatusCode
        }

        if err != nil {
            fmt.Println(err)
            //return response, err
        }

        if err == nil && statusCode == http.StatusOK {
            return response, nil
        }

        if err == nil && response != nil {
            defer req.Body.Close()
        }

        retry := retryDecision(statusCode, attempts, retryAttempts)
        if !retry {
            return response, err
        }

        fmt.Println("Retry Attempt number", attempts)
        time.Sleep(retryDelay * time.Second)
        fmt.Println("After Delay")
    }
}

func retryDecision(responseStatusCode int, attempts int, retryAttempts int) bool {

    retry := false
    fmt.Println("Retry Decision 0 ", responseStatusCode, attempts, retryAttempts)
    errorCodeForRetry :=
        []int{http.StatusInternalServerError, http.StatusUnauthorized, http.StatusNotImplemented, http.StatusBadGateway, http.StatusServiceUnavailable, http.StatusGatewayTimeout}

    for _, code := range errorCodeForRetry {
        if code == responseStatusCode && attempts <= retryAttempts {
            retry = true
        }
    }

    fmt.Println("Retry Decision ", retry)

    return retry

}

请在下面找到错误详细信息

Attempt -  1
ret 88888  &{POST https://localhost:8080/logs/ HTTP/1.1 1 1 map[] {{"converstnId":"","boId":"","msgId":"","serviceName":"","headers":"","properties":"","message":"","body":"aa","exceptionMessage":"","logType":"","exceptionStackTrace":""}}

0x5ec890 170 [] 假地图[] 地图[] 地图[]
}

Attempt -  2
ret 88888  &{POST https://localhost:8080/logs/ HTTP/1.1 1 1 map[] {} 0x5ec890 170 [] false  map[] map[] <nil> map[]

}

4

1 回答 1

8

为了能够重用主体为非零的请求，您首先需要确保主体已关闭，不是由您关闭，而是由客户端的RoundTripper关闭。

文档的相关部分：

RoundTrip 必须始终关闭主体，包括在错误时，但根据实现，即使在 RoundTrip 返回之后，也可能在单独的 goroutine 中这样做。这意味着想要为后续请求重用正文的调用者必须安排在执行此操作之前等待 Close 调用。

当重用没有正文的请求时，比如 GET，你仍然需要小心：

如果请求没有正文，则可以重复使用它，只要调用者在 RoundTrip 失败或 Response.Body 关闭之前不改变 Request 即可。

取自这里。

因此，只要您确定 RoundTripper 关闭了主体，您可以做的就是在每次迭代的顶部重置请求的主体。像这样的东西：

func httpRetry(req *http.Request, timeOut time.Duration, retryAttempts int, retryDelay time.Duration) (*http.Response, error) {

    // ...

    data, err := ioutil.ReadAll(req.Body)
    if err != nil {
        return nil, err
    }

    // close the original body, we don't need it anymore
    if err := req.Body.Close(); err != nil {
        return err
    }

    for {

        req.Body = ioutil.NopCloser(bytes.NewReader(data)) // reset the body

        // ... your code ...

    }

    // ...
}
于 2019-02-15T09:30:39.540 回答