连续调用URL导致异常发生:远程服务器返回一个错误:(500)内部服务器错误

Question

以下是我试图为我需要的应用程序执行的代码片段。我正在记录计数，直到服务器没有抛出异常但是我提供的计数器(i)显示到170-190条记录。

            for (int j = 0; j < 1000 ; j++)
            {
                i++;
                WebRequest request = WebRequest.Create(requestUrl);
                request.Credentials = CredentialCache.DefaultNetworkCredentials;
                using (WebResponse response = request.GetResponse())
                {
                    using (var stream = response.GetResponseStream())
                    {
                        using (var reader = new StreamReader(stream))
                        {
                            var htmlString = reader.ReadToEnd();
                            partialViews.Add(MvcHtmlString.Create(htmlString));
                        }
                    }
                }
            }

我在做什么不正确的事情?有没有办法在这样的循环中连续地从不同的应用程序url中获取html字符串?

我也尝试过使用WebClient类而不是WebRequest和WebResponse

Answer 1

我从恒定接触API v(1)中经历了此错误。当我连接到检查我的活动状态时，这似乎是随机发生的。我要做的是睡30秒，然后再试一次。我把它设置在一个循环中，它最多调用10次。我从来没有叫它超过3。

您将希望捕获GetResponse的500错误(我只在下面粘贴了我的进程请求代码)。您可能需要根据您的需要稍微调整一下这段代码:

        //this is used to call cc multiple times if it returns 500 errors
    public int _iWexCounter;

…

//Process the webrequest
 private string ProcessRequest()
    {
        string sResponse = string.Empty;

        try
        {

            HttpWebResponse ccResponse = (HttpWebResponse)_myWebRequest.GetResponse();
            StreamReader reader = new StreamReader(ccResponse.GetResponseStream());

            sResponse = reader.ReadToEnd();
            // Close Reader
            reader.Close();

            // Close the response to free up the system resources
            ccResponse.Close();
            //the connect to CC was good, reset the wex error counter = 0 
            _iWexCounter = 0;
        }
        catch (WebException wex)
        {
            //if the cc server returns a 500, try to connect to it 10 times before blowing it all up
            if (wex.Message == "The remote server returned an error: (500) Internal Server Error.")
            {
                _iWexCounter++;
                if (_iWexCounter > 10)
                {
                    // Get the web exception type, error number returned here
                    sResponse = "Web Exception: " + wex.Status + wex.Message + wex.StackTrace + wex.GetBaseException().Message + wex.GetBaseException().StackTrace + sResponse;
                    SetConstantContactDifferentialAddTracker(_iConstantContactDifferentialAddTrackerID, "FAILURE", sResponse);
                    _sMessages.Append(wex.Message + Environment.NewLine);
                }
                else
                {
                    sResponse = "500 retry";
                }
            }
        }
        catch (Exception ex)
        {
            // Get the web exception type, error number returned here
            sResponse = "General Exception: " + ex.Message;
            SetConstantContactDifferentialAddTracker(_iConstantContactDifferentialAddTrackerID, "FAILURE", sResponse);
            _sMessages.Append(ex.Message + Environment.NewLine);
        }
        return sResponse;
    }