Question

我需要确定用户列表是否在第三方用户目录中。我在C＃.NET 4.0中编写该方法。用户列表超过2700个条目。访问此用户目录的API使用REST返回用户信息。如果用户不在目录中，则对HttpWebRequest的响应是404错误。我抓住了WebException错误。

问题是我一次只能获得1个用户的用户信息，所以我想通过用户列表进行for循环。但是，当404错误发生时，它会突然出现循环。有没有办法捕获404错误并继续与下一个用户循环？

这是我的代码：

    public void GetRecipientDataFromCortext()
{
    SqlConnection SqlConn = null;
    CortextUser objCortextResult;
    try
    {
        string strStoredProcedure = "PagingToolGetRecipientsAndDevices";
        DataTable tdtRecipientData = new DataTable("RecipientData");
        //Create a datatable to store final results
        DataTable tdtCortextResultData = new DataTable("CortextResults");
        tdtCortextResultData.Columns.Add("RecipientID", typeof(int));
        tdtCortextResultData.Columns.Add("DeviceTypeID", typeof(int));
        tdtCortextResultData.Columns.Add("DeviceAddress", typeof(string));
        tdtCortextResultData.Columns.Add("CUID", typeof(string));
        tdtCortextResultData.Columns.Add("InviteStatus", typeof(string));
        tdtCortextResultData.Columns.Add("IsEnabled", typeof(bool));
        tdtCortextResultData.Columns.Add("FirstName", typeof(string));
        tdtCortextResultData.Columns.Add("LastName", typeof(string));
        tdtCortextResultData.Columns.Add("MiddleName", typeof(string));
        tdtCortextResultData.Columns.Add("HonorificPrefix", typeof(string));
        tdtCortextResultData.Columns.Add("HonorificSuffix", typeof(string));
        tdtCortextResultData.Columns.Add("Email", typeof(string));
        tdtCortextResultData.Columns.Add("Mobile", typeof(string));
        tdtCortextResultData.Columns.Add("Pager", typeof(string));

        string strSqlConnection = ConfigurationManager.ConnectionStrings[CONNECTION_STRING].ConnectionString;
        //Get the recipient list from the database
        using (SqlConn = new SqlConnection(strSqlConnection))
        {
            using (SqlCommand SqlCmd = new SqlCommand(strStoredProcedure, SqlConn))
            {
                SqlCmd.CommandType = CommandType.StoredProcedure;
                SqlConn.Open();
                using (SqlDataAdapter dataReturned = new SqlDataAdapter(SqlCmd))
                {
                    dataReturned.Fill(tdtRecipientData);                         
                }
            }
        }
        //For loop to make a call to cortext to get properties of this device 
        string tstrPropertyValue = string.Empty;
        string tstrProperty = string.Empty;
        int tiDeviceTypeID;
        int tiRecipientID;

        //This is the for loop to check each recipient to see if he/she is in the directory
        foreach (DataRow row in tdtRecipientData.Rows)
        {               
            tstrPropertyValue = row["Address"].ToString();
            tiDeviceTypeID = Convert.ToInt32(row["DeviceTypeID"].ToString());
            tiRecipientID = Convert.ToInt32(row["RecipientID"].ToString());

            //Insert into the Cortext table initial values first
            //This inserts into a database table the user to check.
            //This table is used to get the initial recipient list. 
            //Any users in this table are not in the list.
            InsertCortextInformation(tiRecipientID, tiDeviceTypeID, tstrPropertyValue);

            switch (tiDeviceTypeID)
            {
                case 1:
                    tstrProperty = "mobile";
                    break;
                case 2:
                    tstrProperty = "email";
                    break;
                case 3:
                    tstrProperty = "pager";
                    break;
                default:
                    break;
            }

            //Results from cortext call add to data table
            //User not in the directory results in this method call to return a 404 error.
            //Exception breaks out of the loop
            objCortextResult = GetCortextUserInformation(tstrProperty, tstrPropertyValue);
            //Add results to datatable
            DataRow newRow = tdtCortextResultData.NewRow();
            newRow["RecipientID"] = Convert.ToInt32(row["RecipientID"].ToString());
            newRow["DeviceTypeID"] = Convert.ToInt32(row["DeviceTypeID"].ToString());
            newRow["DeviceAddress"] = row["Address"].ToString();
            newRow["CUID"] = objCortextResult.CUID;
            newRow["InviteStatus"] = objCortextResult.inviteStatus;
            newRow["IsEnabled"] = objCortextResult.isEnabled;
            newRow["FirstName"] = objCortextResult.userFirstName;
            newRow["LastName"] = objCortextResult.userLastName;
            newRow["MiddleName"] = objCortextResult.userMiddleName;
            newRow["HonorificPrefix"] = objCortextResult.userHonorificPrefix;
            newRow["HonorificSuffix"] = objCortextResult.userHonorificSuffix;
            newRow["Email"] = objCortextResult.email;
            newRow["Mobile"] = objCortextResult.mobile;
            newRow["Pager"] = objCortextResult.pager;

            tdtCortextResultData.Rows.Add(newRow);

        }

        //Insert data table results into Paging Tool table, PagingToolCortextInfo
        int tiRecID, tiDeviceID;
        bool tbIsEnabled;
        foreach (DataRow row in tdtCortextResultData.Rows)
        {
            tiRecID = Convert.ToInt32(row["RecipientID"].ToString());
            tiDeviceID = Convert.ToInt32(row["DeviceTypeID"].ToString());
            tbIsEnabled = Convert.ToBoolean(row["IsEnabled"].ToString());
            UpdateCortextInformation(tiRecID, tiDeviceID, row["DeviceAddress"].ToString(),
                                        row["CUID"].ToString(), row["InviteStatus"].ToString(), tbIsEnabled,
                                        row["FirstName"].ToString(), row["LastName"].ToString(), row["MiddleName"].ToString(),
                                        row["HonorificPrefix"].ToString(), row["HonorificSuffix"].ToString(),
                                        row["Email"].ToString(), row["Mobile"].ToString(), row["Pager"].ToString());
        }

    }
    //Catches the HttpWebResponse errors like 404
    catch (WebException e)
    {
        using (WebResponse response = e.Response)
        {
            HttpWebResponse httpResponse = (HttpWebResponse)response;
            string errorMessage = string.Format("Error code: {0} ", httpResponse.StatusCode);
            //         System.Diagnostics.Debug.WriteLine("Error code: {0}", httpResponse.StatusCode);
            using (Stream data = response.GetResponseStream())
            {
                using (var reader = new StreamReader(data))
                {
                    string text = reader.ReadToEnd();
                    errorMessage += text;
                    //
                    System.Diagnostics.Debug.WriteLine(text);
                    logger.ErrorException(errorMessage, e);
                }
            }
        }
        throw;
    }
    catch (Exception ex)
    {
        logger.ErrorException(ex.Message, ex);
        throw;
    }
    finally
    {
        if (SqlConn != null)
        {
            SqlConn.Close();
        }
    }
}

那么，在调用Http响应返回404错误并获得下一个用户之后，有没有办法在for循环中继续？

我想承认404错误，并继续在for循环中获取所有用户。

感谢。

Answer 1

使用您的代码可以很容易地实现这一点：）

换行：

objCortextResult = GetCortextUserInformation(tstrProperty, tstrPropertyValue);

在try catch中

：

var isNotFound = false;
try {
    objCortextResult = GetCortextUserInformation(tstrProperty, tstrPropertyValue);
}
catch(WebException ex) {
    if(((HttpWebResponse)ex.Response).StatusCode == HttpStatusCode.NotFound)       
    {
        isNotFound = true;
    }
    else {
        throw;
    }
}

if (isNotFound) continue;

...

状态码404的继续将进入循环的下一次迭代并实现所需的行为。

如果您还有其他需要，请告诉我们！

Answer 2

你可以尝试保持try catch for循环吗？您也可以尝试为每个或TPL并行执行此操作。

在HttpWebRequest响应返回404错误后继续

2 个答案: