订阅交换流通知时出现异常
Exception when subscribing to exchange streaming notifications
我目前正在从事一个让我与 Exchange 集成的项目。其中一项要求是监视邮箱中是否有新的传入消息，我认为利用 streaming 通知是个好主意。
我编写了一个示例应用程序来熟悉如何利用流式通知，但是我遇到了以下错误：The expected XML node type was Element, but the actual type is Text.
以下是我写的示例应用程序的来源：
using Microsoft.Exchange.WebServices.Data;
using System;
using System.Net;
namespace ExampleProgram
{
class Program
{
public static StreamingSubscriptionConnection streamingConnection;
public static bool RedirectionUrlValidationCallback(string redirectionUrl)
{
bool result = false;
Uri redirectionUri = new Uri(redirectionUrl);
if (redirectionUri.Scheme == "https")
{
result = true;
}
return result;
}
public static void NewMailSubscriptionDisconnect(object sender, SubscriptionErrorEventArgs args)
{
Exception e = args.Exception;
Console.Write("Disconnect: ");
Console.WriteLine(e.Message);
if (streamingConnection != null && !streamingConnection.IsOpen)
{
streamingConnection.Open();
}
}
public static void NewMailSubscriptionError(object sender, SubscriptionErrorEventArgs args)
{
Exception e = args.Exception;
Console.Write("Disconnect: ");
Console.WriteLine(e.Message);
}
public static void NewMailSubscriptionNotification(object sender, NotificationEventArgs args)
{
Console.WriteLine("New message has arrived");
}
static void Main(string[] args)
{
var exchangeService = new ExchangeService(ExchangeVersion.Exchange2013_SP1);
exchangeService.Credentials = new NetworkCredential("username", "password", "domain");
exchangeService.TraceEnabled = true;
exchangeService.TraceFlags = TraceFlags.All;
exchangeService.TraceEnablePrettyPrinting = true;
exchangeService.AutodiscoverUrl("username@example.com", RedirectionUrlValidationCallback);
var newMailSubscription = exchangeService.SubscribeToStreamingNotificationsOnAllFolders(EventType.NewMail);
streamingConnection = new StreamingSubscriptionConnection(exchangeService, 30);
streamingConnection.AddSubscription(newMailSubscription);
streamingConnection.OnNotificationEvent += new StreamingSubscriptionConnection.NotificationEventDelegate(NewMailSubscriptionNotification);
streamingConnection.OnSubscriptionError += new StreamingSubscriptionConnection.SubscriptionErrorDelegate(NewMailSubscriptionError);
streamingConnection.OnDisconnect += new StreamingSubscriptionConnection.SubscriptionErrorDelegate(NewMailSubscriptionDisconnect);
streamingConnection.Open();
do { } while (Console.ReadKey(true).Key != ConsoleKey.Escape);
}
}
}
正如您从上面的源代码中看到的那样，我打开了跟踪功能。以下是从这些痕迹中产生的结果：
EwsResponseHttpHeader
<Trace Tag="EwsResponseHttpHeaders" Tid="17" Time="2015-10-20 17:42:31Z">
HTTP/1.1 200 OK
Transfer-Encoding: chunked
request-id: <redacted>
X-CalculatedBETarget: EXAMPLE-EXCHANGE-01.example.com
X-NoBuffering: 1
X-DiagInfo: EXAMPLE-EXCHANGE-01
X-BEServer: EXAMPLE-EXCHANGE-01
Cache-Control: private
Set-Cookie: exchangecookie=<redacted>; path=/,X-BackEndCookie=<redacted>; expires=Thu, 19-Nov-2015 17:42:30 GMT; path=/ews; secure; HttpOnly
Server: Microsoft-IIS/8.5
X-AspNet-Version: 4.0.30319
Persistent-Auth: true
X-Powered-By: ASP.NET
X-FEServer: EXAMPLE-EXCHANGE-02
Date: Tue, 20 Oct 2015 17:42:30 GMT
</Trace>
EwsResponse
<Trace Tag="EwsResponse"
Tid="15"
Time="2015-10-20 16:52:07Z"
Version="0.0.0.0">
417 <!-- What is this? -->
<Envelope xmlns="http://schemas.xmlsoap.org/soap/envelope/">
<soap11:Header xmlns:soap11="http://schemas.xmlsoap.org/soap/envelope/">
<ServerVersionInfo xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
MajorVersion="15"
MinorVersion="0"
MajorBuildNumber="1130"
MinorBuildNumber="6"
Version="V2_23"
xmlns="http://schemas.microsoft.com/exchange/services/2006/types" />
</soap11:Header>
<soap11:Body xmlns:soap11="http://schemas.xmlsoap.org/soap/envelope/">
<m:GetStreamingEventsResponse xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types"
xmlns:m="http://schemas.microsoft.com/exchange/services/2006/messages">
<m:ResponseMessages>
<m:GetStreamingEventsResponseMessage ResponseClass="Success">
<m:ResponseCode>NoError</m:ResponseCode>
<m:ConnectionStatus>OK</m:ConnectionStatus>
</m:GetStreamingEventsResponseMessage>
</m:ResponseMessages>
</m:GetStreamingEventsResponse>
</soap11:Body>
</Envelope>
2 <!-- Not sure what this is either... -->
</Trace>
异常详细信息
Microsoft.Exchange.WebServices.Data.ServiceXmlDeserializationException occurred
HResult=-2146233088
Message=The expected XML node type was Element, but the actual type is Text.
Source=Microsoft.Exchange.WebServices
StackTrace:
at Microsoft.Exchange.WebServices.Data.EwsXmlReader.Read(XmlNodeType nodeType) in C:\Projects\ews-managed-api\Core\EwsXmlReader.cs:line 187
InnerException:
EwsXmlReader.cs 的来源可在以下位置找到：https://github.com/OfficeDev/ews-managed-api/blob/master/Core/EwsXmlReader.cs
看起来 "something" 是在 417 前面加上 2 到来自 Exchange 服务器的响应。对我来说，为什么抛出异常是很明显的，在不应该存在的地方有文本数据。对我来说不明显的是为什么文本数据在那里。
有什么想法吗？
Transfer-Encoding: chunked
这就是这个谜题的关键，您看到的是 "chunks"。 417 是删除漂亮打印格式时 <Envelope> 块长度的十六进制值。 2 是最后一个块，就是 whitespace。分块传输格式为 explained here.
我重新格式化了 XML 以删除白色 space，你可以算出 0x417 = 1047 个字符：
<Envelope xmlns="http://schemas.xmlsoap.org/soap/envelope/"><soap11:Header xmlns:soap11="http://schemas.xmlsoap.org/soap/envelope/"><ServerVersionInfo xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" MajorVersion="15" MinorVersion="0" MajorBuildNumber="1130" MinorBuildNumber="6" Version="V2_23" xmlns="http://schemas.microsoft.com/exchange/services/2006/types"/></soap11:Header><soap11:Body xmlns:soap11="http://schemas.xmlsoap.org/soap/envelope/"><m:GetStreamingEventsResponse xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types" xmlns:m="http://schemas.microsoft.com/exchange/services/2006/messages"><m:ResponseMessages><m:GetStreamingEventsResponseMessage ResponseClass="Success"><m:ResponseCode>NoError</m:ResponseCode><m:ConnectionStatus>OK</m:ConnectionStatus></m:GetStreamingEventsResponseMessage></m:ResponseMessages></m:GetStreamingEventsResponse></soap11:Body></Envelope>
显然 HTTP 传输应该删除它们，您的问题没有给出为什么没有发生这种情况的正确线索。但希望有一个很好的线索来找到根本原因。有趣的拼图顺便说一句:)
我目前正在从事一个让我与 Exchange 集成的项目。其中一项要求是监视邮箱中是否有新的传入消息，我认为利用 streaming 通知是个好主意。
我编写了一个示例应用程序来熟悉如何利用流式通知，但是我遇到了以下错误：The expected XML node type was Element, but the actual type is Text.
以下是我写的示例应用程序的来源：
using Microsoft.Exchange.WebServices.Data;
using System;
using System.Net;
namespace ExampleProgram
{
class Program
{
public static StreamingSubscriptionConnection streamingConnection;
public static bool RedirectionUrlValidationCallback(string redirectionUrl)
{
bool result = false;
Uri redirectionUri = new Uri(redirectionUrl);
if (redirectionUri.Scheme == "https")
{
result = true;
}
return result;
}
public static void NewMailSubscriptionDisconnect(object sender, SubscriptionErrorEventArgs args)
{
Exception e = args.Exception;
Console.Write("Disconnect: ");
Console.WriteLine(e.Message);
if (streamingConnection != null && !streamingConnection.IsOpen)
{
streamingConnection.Open();
}
}
public static void NewMailSubscriptionError(object sender, SubscriptionErrorEventArgs args)
{
Exception e = args.Exception;
Console.Write("Disconnect: ");
Console.WriteLine(e.Message);
}
public static void NewMailSubscriptionNotification(object sender, NotificationEventArgs args)
{
Console.WriteLine("New message has arrived");
}
static void Main(string[] args)
{
var exchangeService = new ExchangeService(ExchangeVersion.Exchange2013_SP1);
exchangeService.Credentials = new NetworkCredential("username", "password", "domain");
exchangeService.TraceEnabled = true;
exchangeService.TraceFlags = TraceFlags.All;
exchangeService.TraceEnablePrettyPrinting = true;
exchangeService.AutodiscoverUrl("username@example.com", RedirectionUrlValidationCallback);
var newMailSubscription = exchangeService.SubscribeToStreamingNotificationsOnAllFolders(EventType.NewMail);
streamingConnection = new StreamingSubscriptionConnection(exchangeService, 30);
streamingConnection.AddSubscription(newMailSubscription);
streamingConnection.OnNotificationEvent += new StreamingSubscriptionConnection.NotificationEventDelegate(NewMailSubscriptionNotification);
streamingConnection.OnSubscriptionError += new StreamingSubscriptionConnection.SubscriptionErrorDelegate(NewMailSubscriptionError);
streamingConnection.OnDisconnect += new StreamingSubscriptionConnection.SubscriptionErrorDelegate(NewMailSubscriptionDisconnect);
streamingConnection.Open();
do { } while (Console.ReadKey(true).Key != ConsoleKey.Escape);
}
}
}
正如您从上面的源代码中看到的那样，我打开了跟踪功能。以下是从这些痕迹中产生的结果：
EwsResponseHttpHeader
<Trace Tag="EwsResponseHttpHeaders" Tid="17" Time="2015-10-20 17:42:31Z">
HTTP/1.1 200 OK
Transfer-Encoding: chunked
request-id: <redacted>
X-CalculatedBETarget: EXAMPLE-EXCHANGE-01.example.com
X-NoBuffering: 1
X-DiagInfo: EXAMPLE-EXCHANGE-01
X-BEServer: EXAMPLE-EXCHANGE-01
Cache-Control: private
Set-Cookie: exchangecookie=<redacted>; path=/,X-BackEndCookie=<redacted>; expires=Thu, 19-Nov-2015 17:42:30 GMT; path=/ews; secure; HttpOnly
Server: Microsoft-IIS/8.5
X-AspNet-Version: 4.0.30319
Persistent-Auth: true
X-Powered-By: ASP.NET
X-FEServer: EXAMPLE-EXCHANGE-02
Date: Tue, 20 Oct 2015 17:42:30 GMT
</Trace>
EwsResponse
<Trace Tag="EwsResponse"
Tid="15"
Time="2015-10-20 16:52:07Z"
Version="0.0.0.0">
417 <!-- What is this? -->
<Envelope xmlns="http://schemas.xmlsoap.org/soap/envelope/">
<soap11:Header xmlns:soap11="http://schemas.xmlsoap.org/soap/envelope/">
<ServerVersionInfo xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
MajorVersion="15"
MinorVersion="0"
MajorBuildNumber="1130"
MinorBuildNumber="6"
Version="V2_23"
xmlns="http://schemas.microsoft.com/exchange/services/2006/types" />
</soap11:Header>
<soap11:Body xmlns:soap11="http://schemas.xmlsoap.org/soap/envelope/">
<m:GetStreamingEventsResponse xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types"
xmlns:m="http://schemas.microsoft.com/exchange/services/2006/messages">
<m:ResponseMessages>
<m:GetStreamingEventsResponseMessage ResponseClass="Success">
<m:ResponseCode>NoError</m:ResponseCode>
<m:ConnectionStatus>OK</m:ConnectionStatus>
</m:GetStreamingEventsResponseMessage>
</m:ResponseMessages>
</m:GetStreamingEventsResponse>
</soap11:Body>
</Envelope>
2 <!-- Not sure what this is either... -->
</Trace>
异常详细信息
Microsoft.Exchange.WebServices.Data.ServiceXmlDeserializationException occurred
HResult=-2146233088
Message=The expected XML node type was Element, but the actual type is Text.
Source=Microsoft.Exchange.WebServices
StackTrace:
at Microsoft.Exchange.WebServices.Data.EwsXmlReader.Read(XmlNodeType nodeType) in C:\Projects\ews-managed-api\Core\EwsXmlReader.cs:line 187
InnerException:
EwsXmlReader.cs 的来源可在以下位置找到：https://github.com/OfficeDev/ews-managed-api/blob/master/Core/EwsXmlReader.cs
看起来 "something" 是在 417 前面加上 2 到来自 Exchange 服务器的响应。对我来说，为什么抛出异常是很明显的，在不应该存在的地方有文本数据。对我来说不明显的是为什么文本数据在那里。
有什么想法吗？
Transfer-Encoding: chunked
这就是这个谜题的关键，您看到的是 "chunks"。 417 是删除漂亮打印格式时 <Envelope> 块长度的十六进制值。 2 是最后一个块，就是 whitespace。分块传输格式为 explained here.
我重新格式化了 XML 以删除白色 space，你可以算出 0x417 = 1047 个字符：
<Envelope xmlns="http://schemas.xmlsoap.org/soap/envelope/"><soap11:Header xmlns:soap11="http://schemas.xmlsoap.org/soap/envelope/"><ServerVersionInfo xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" MajorVersion="15" MinorVersion="0" MajorBuildNumber="1130" MinorBuildNumber="6" Version="V2_23" xmlns="http://schemas.microsoft.com/exchange/services/2006/types"/></soap11:Header><soap11:Body xmlns:soap11="http://schemas.xmlsoap.org/soap/envelope/"><m:GetStreamingEventsResponse xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types" xmlns:m="http://schemas.microsoft.com/exchange/services/2006/messages"><m:ResponseMessages><m:GetStreamingEventsResponseMessage ResponseClass="Success"><m:ResponseCode>NoError</m:ResponseCode><m:ConnectionStatus>OK</m:ConnectionStatus></m:GetStreamingEventsResponseMessage></m:ResponseMessages></m:GetStreamingEventsResponse></soap11:Body></Envelope>
显然 HTTP 传输应该删除它们，您的问题没有给出为什么没有发生这种情况的正确线索。但希望有一个很好的线索来找到根本原因。有趣的拼图顺便说一句:)