我想获取所有 Azure Table 错误的列表,并找出一种在try...catch
块中处理它们的干净方法。
例如,我不想直接编写代码并将 InnerException 消息与String.Contains("The specified entity already exists")
. 捕获这些错误的正确方法是什么?
我想获取所有 Azure Table 错误的列表,并找出一种在try...catch
块中处理它们的干净方法。
例如,我不想直接编写代码并将 InnerException 消息与String.Contains("The specified entity already exists")
. 捕获这些错误的正确方法是什么?
您可以尝试查看响应中的值,而不是内部异常。这是我的一个 try catch 块的示例:
try {
return query.FirstOrDefault();
}
catch (System.Data.Services.Client.DataServiceQueryException ex)
{
if (ex.Response.StatusCode == (int)System.Net.HttpStatusCode.NotFound) {
return null;
}
throw;
}
显然,这只是针对 item doesn't exist 错误,但我相信您可以通过查看Azure 错误代码列表来扩展此概念。
要在将对象添加到表时处理错误,您可以使用以下代码:
try {
_context.AddObject(TableName, entityObject);
_context.SaveCangesWithRetries();
}
catch(DataServiceRequestException ex) {
ex.Response.Any(r => r.StatusCode == (int)System.Net.HttpStatusCode.Conflict)
throw;
}
如其他答案所述,您可以在以下位置找到 TableStorage 错误列表:http: //msdn.microsoft.com/en-us/library/dd179438.aspx
在此处查看我的代码:http: //blog.smarx.com/posts/testing-existence-of-a-windows-azure-blob。该模式是捕获 StorageClientException,然后使用 .ErrorCode 属性与 StorageErrorCode 中的常量进行匹配。
这是Azure Table Whitepaper 中提供的代码,但我不确定这是否比 smark 的回复更有价值。
/*
From Azure table whitepaper
When an exception occurs, you can extract the sequence number (highlighted above) of the command that caused the transaction to fail as follows:
try
{
// ... save changes
}
catch (InvalidOperationException e)
{
DataServiceClientException dsce = e.InnerException as DataServiceClientException;
int? commandIndex;
string errorMessage;
ParseErrorDetails(dsce, out commandIndex, out errorMessage);
}
*/
-
void ParseErrorDetails( DataServiceClientException e, out string errorCode, out int? commandIndex, out string errorMessage)
{
GetErrorInformation(e.Message, out errorCode, out errorMessage);
commandIndex = null;
int indexOfSeparator = errorMessage.IndexOf(':');
if (indexOfSeparator > 0)
{
int temp;
if (Int32.TryParse(errorMessage.Substring(0, indexOfSeparator), out temp))
{
commandIndex = temp;
errorMessage = errorMessage.Substring(indexOfSeparator + 1);
}
}
}
void GetErrorInformation( string xmlErrorMessage, out string errorCode, out string message)
{
message = null;
errorCode = null;
XName xnErrorCode = XName.Get("code", "http://schemas.microsoft.com/ado/2007/08/dataservices/metadata");
XName xnMessage = XName.Get ( "message", "http://schemas.microsoft.com/ado/2007/08/dataservices/metadata");
using (StringReader reader = new StringReader(xmlErrorMessage))
{
XDocument xDocument = null;
try
{
xDocument = XDocument.Load(reader);
}
catch (XmlException)
{
// The XML could not be parsed. This could happen either because the connection
// could not be made to the server, or if the response did not contain the
// error details (for example, if the response status code was neither a failure
// nor a success, but a 3XX code such as NotModified.
return;
}
XElement errorCodeElement = xDocument.Descendants(xnErrorCode).FirstOrDefault();
if (errorCodeElement == null)
{
return;
}
errorCode = errorCodeElement.Value;
XElement messageElement = xDocument.Descendants(xnMessage).FirstOrDefault();
if (messageElement != null)
{
message = messageElement.Value;
}
}
}