WCF REST 完整服务中的异常处理
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【中文标题】WCF REST 完整服务中的异常处理【英文标题】:Exception Handling in WCF REST Full Service 【发布时间】:2014-11-22 02:59:42 【问题描述】:我正在使用 WCF Service 4.5 F/W 开发 REST Full API。请建议如何向客户发送异常或任何业务验证消息。我正在寻找一个非常通用的解决方案,请建议最好的方法。 我尝试了以下一些方法,
在向客户端发送响应之前设置 OutgoingWebResponseContext。
定义的故障合约只能正常工作 添加服务引用(代理类)在 REST FULL 环境中不起作用。
在 catch 块中添加 WebFaultException 类。
WCF Rest Starter Kit - 我收到了一些关于此的文章和帖子,但他们的 CodePlex 官方网站建议不再提供此功能。 link。所以,我不想这样做。
这些没有按预期工作.. 我的示例代码片段: 接口:
[OperationContract]
[FaultContract(typeof(MyExceptionContainer))]
[WebInvoke(Method = "GET", UriTemplate = "/Multiply/num1/num2", BodyStyle = WebMessageBodyStyle.Wrapped,RequestFormat = WebMessageFormat.Xml, ResponseFormat = WebMessageFormat.Xml)]
string Multiply(string num1, string num2);
实施:
public string Multiply(string num1, string num2)
if (num1 == "0" || num2 == "0")
try
MyExceptionContainer exceptionDetails = new MyExceptionContainer();
exceptionDetails.Messsage = "Business Rule violatuion";
exceptionDetails.Description = "The numbers should be non zero to perform this operation";
//OutgoingWebResponseContext outgoingWebResponseContext = WebOperationContext.Current.OutgoingResponse;
//outgoingWebResponseContext.StatusCode = System.Net.HttpStatusCode.ExpectationFailed;
//outgoingWebResponseContext.StatusDescription = exceptionDetails.Description.ToString();
// throw new WebFaultException<MyExceptionContainer>(exceptionDetails,System.Net.HttpStatusCode.Gone);
throw new FaultException<MyExceptionContainer>(exceptionDetails,new FaultReason("FaultReason is " + exceptionDetails.Messsage + " - " + exceptionDetails.Description));
catch (Exception ex)
throw new FaultException(ex.Message);
return Convert.ToString(Int32.Parse(num1) * Int32.Parse(num2));
Web.Config:
<system.serviceModel>
<services>
<service name="TestService.TestServiceImplementation" behaviorConfiguration="ServiceBehaviour">
<endpoint binding="webHttpBinding" contract="TestService.ITestService" behaviorConfiguration="webHttp" >
</endpoint>
</service>
</services>
<behaviors>
<serviceBehaviors>
<behavior name="ServiceBehaviour">
<!-- To avoid disclosing metadata information, set the value below to false and remove the metadata endpoint above before deployment -->
<serviceMetadata httpGetEnabled="true"/>
<!-- To receive exception details in faults for debugging purposes, set the value below to true. Set to false before deployment to avoid disclosing exception information -->
<serviceDebug includeExceptionDetailInFaults="true"/>
</behavior>
</serviceBehaviors>
<endpointBehaviors>
<behavior name="webHttp" >
<webHttp helpEnabled="true" faultExceptionEnabled="true"/>
</behavior>
</endpointBehaviors>
</behaviors>
<serviceHostingEnvironment multipleSiteBindingsEnabled="true" />
客户:
try
string serviceUrl = "http://localhost:51775/TestService.cs.svc/Multiply/0/0";
//Web Client
//WebClient webClient = new WebClient();
//string responseString = webClient.DownloadString(serviceUrl);
WebRequest req = WebRequest.Create(serviceUrl);
req.Method = "GET";
req.ContentType = @"application/xml; charset=utf-8";
HttpWebResponse resp = req.GetResponse() as HttpWebResponse;
if (resp.StatusCode == HttpStatusCode.OK)
XmlDocument myXMLDocument = new XmlDocument();
XmlReader myXMLReader = new XmlTextReader(resp.GetResponseStream());
myXMLDocument.Load(myXMLReader);
Console.WriteLine(myXMLDocument.InnerText);
Console.ReadKey();
catch (Exception ex)
Console.WriteLine(ex.Message);
这是我的第一个问题,感谢所有热情的开发者..!
【问题讨论】:
【参考方案1】:Web.Config:
<system.serviceModel>
<services>
<service name="TestService.TestServiceImplementation">
<endpoint address=""
binding="webHttpBinding"
contract="TestService.Service.ITestServiceImplementation" />
<service/>
<services/>
<behaviors>
<serviceBehaviors>
<behavior>
<serviceMetadata httpGetEnabled="true"/>
<serviceDebug includeExceptionDetailInFaults="true"/>
<behavior/>
<serviceBehaviors/>
<behaviors/>
<serviceHostingEnvironment multipleSiteBindingsEnabled="true" />
<system.serviceModel/>
<system.webServer>
<modules runAllManagedModulesForAllRequests="true"/>
<directoryBrowse enabled="true"/>
<system.webServer/>
实施:
public string Multiply(string num1, string num2)
if (num1 == "0" || num2 == "0")
try
MyExceptionContainer exceptionDetails = new MyExceptionContainer();
exceptionDetails.Messsage = "Business Rule violatuion";
exceptionDetails.Description = "The numbers should be non zero to perform this operation";
//OutgoingWebResponseContext outgoingWebResponseContext = WebOperationContext.Current.OutgoingResponse;
//outgoingWebResponseContext.StatusCode = System.Net.HttpStatusCode.ExpectationFailed;
//outgoingWebResponseContext.StatusDescription = exceptionDetails.Description.ToString();
// throw new WebFaultException<MyExceptionContainer>(exceptionDetails,System.Net.HttpStatusCode.Gone);
throw new FaultException<MyExceptionContainer>(exceptionDetails,new FaultReason("FaultReason is " + exceptionDetails.Messsage + " - " + exceptionDetails.Description));
catch (FaultException ex)
throw new FaultException(ex.Message);
return Convert.ToString(Int32.Parse(num1) * Int32.Parse(num2));
【讨论】:
【参考方案2】:不要使用FaultException
,而是使用以下内容:
服务器:
catch (Exception ex)
throw new System.ServiceModel.Web.WebFaultException<string>(ex.ToString(), System.Net.HttpStatusCode.BadRequest);
客户:
catch (Exception ex)
var protocolException = ex as ProtocolException;
var webException = protocolException.InnerException as WebException;
if (protocolException != null && webException != null)
var responseStream = webException.Response.GetResponseStream();
var error = new StreamReader(webException.Response.GetResponseStream()).ReadToEnd();
throw new Exception(error);
else
throw new Exception("There is an unexpected error with reading the stream.", ex);
【讨论】:
感谢您的回复。我已经尝试过使用 WebFaultException 但没有运气我仍然无法在客户端获得实际的异常 @SJAlex 请参阅我的更新如何捕获和处理异常。还有其他方法可以通过抛出异常,但我是这样做的。 我不得不调用 responseStream.Seek(0, System.IO.SeekOrigin.Begin);由于某种原因,流不在开始位置。【参考方案3】:在 wcf 中创建真正的 rest 几乎是不可能的,但利用部分 http协议当然是可能的。
要控制服务中的错误消息,您必须提供一个错误处理程序(一个错误处理程序实现),它挂接到 wcf 堆栈并覆盖此处定义的任何错误处理。
这个接口包含两个方法。一个通知 wcf 是否可以处理某个异常(bool HandleError),如果 HandleError 返回 true,则另一个调用。第二种方法 ProvideFault 让您定义在异常情况下如何响应客户端。
您可以链接处理程序以获得更多粒度。由于您正在休息,因此您可能应该使用 httpstatus 代码来告知适用的错误情况。
http://blogs.msdn.com/b/carlosfigueira/archive/2011/06/07/wcf-extensibility-ierrorhandler.aspx
http://www.remondo.net/wcf-global-exception-handling-attribute-and-ierrorhandler/
【讨论】:
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