Question

我做了我的自定义异常，每次发生错误时都会在try-catch中抛出：

[Serializable]
public class CustomException : Exception
{
    public CustomException() { }

    public CustomException(string message)
        : base(message) { }

    public CustomException(string message, Exception innerException)
        : base(message, innerException) { }
}

我有两个服务，REST和SOAP。对于SOAP服务，我在抛出自定义异常时没有任何问题。但是在REST中，我遇到了很多困难。

以下是抛出WebFaultException的方法：

    public static WebFaultException RestGetFault(ServiceFaultTypes fault)
    {
        ServiceFault serviceFault = new ServiceFault();
        serviceFault.Code = (int)fault;
        serviceFault.Description = ConfigAndResourceComponent.GetResourceString(fault.ToString());
        FaultCode faultCode = new FaultCode(fault.ToString());
        FaultReasonText faultReasonText = new FaultReasonText(serviceFault.Description);
        FaultReason faultReason = new FaultReason(faultReasonText);
        WebFaultException<ServiceFault> webfaultException = new WebFaultException<ServiceFault>(serviceFault, HttpStatusCode.InternalServerError);

        throw webfaultException;
    }

ServiceFault是一个类，它有一些属性，我用它来提供我需要的所有信息。

我使用此方法在REST服务中引发异常：

    public static CustomException GetFault(ServiceFaultTypes fault)
    {
        string message = fault.ToString();
        CustomException cusExcp = new CustomException(message, new Exception(message));
        throw cusExcp;
    }

示例REST服务（登录方法）：

    [WebInvoke(UriTemplate = "Login", Method = "POST", ResponseFormat = WebMessageFormat.Json, RequestFormat = WebMessageFormat.Json, BodyStyle = WebMessageBodyStyle.WrappedRequest)]
    public Session Login(ClientCredentials client, LogCredentials loginfo)
    {
        try
        {
            // Login process
            return copied;
        }
        catch (LogicClass.CustomException ex)
        {
            LogicClass.RestGetFault(LogicClass.EnumComponent.GetServiceFaultTypes(ex.Message));
            throw ex;
        }
    }

MVC部分：

控制器：

    [HttpPost]
    public ActionResult Login(LoginCredentials loginfo)
    {
        try
        {
            string param = "{\"client\":" + JSonHelper.Serialize<ClientAuthentication>(new ClientAuthentication() { SessionID = Singleton.ClientSessionID })
                           + ", \"loginfo\":" + JSonHelper.Serialize<LoginCredentials>(loginfo) + "}";

            string jsonresult = ServiceCaller.Invoke(Utility.ConstructRestURL("Authenticate/Login"), param, "POST", "application/json");
            UserSessionDTO response = JSonHelper.Deserialize<UserSessionDTO>(jsonresult);

        }
        catch (Exception ex)
        {
            return Json(new
            {
                status = ex.Message,
                url = string.Empty
            });
        }

        return Json(new
        {
            status = "AUTHENTICATED",
            url = string.IsNullOrWhiteSpace(loginfo.r) ? Url.Action("Index", "Home") : loginfo.r
        });
    }

我使用ServiceCaller.Invoke来调用REST API并检索响应： ServiceCaller.cs

public class ServiceCaller
{
    public static string Invoke(string url, string parameters, string method, string contentType)
    {
        string results = string.Empty;
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(new Uri(url));
        request.Method = method;
        request.ContentType = contentType;

        if (!string.IsNullOrEmpty(parameters))
        {
            byte[] byteArray = Encoding.UTF8.GetBytes(parameters);
            request.ContentLength = byteArray.Length;
            Stream dataStream = request.GetRequestStream();
            dataStream.Write(byteArray, 0, byteArray.Length);
            dataStream.Close();
        }

        try
        {
            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            if (HttpStatusCode.OK == response.StatusCode)
            {
                Stream responseStream = response.GetResponseStream();
                int length = (int)response.ContentLength;

                const int bufSizeMax = 65536;
                const int bufSizeMin = 8192;
                int bufSize = bufSizeMin;

                if (length > bufSize) bufSize = length > bufSizeMax ? bufSizeMax : length;

                byte[] buf = new byte[bufSize];
                StringBuilder sb = new StringBuilder(bufSize);

                while ((length = responseStream.Read(buf, 0, buf.Length)) != 0)
                    sb.Append(Encoding.UTF8.GetString(buf, 0, length));

                results = sb.ToString();
            }
            else
            {
                results = "Failed Response : " + response.StatusCode;
            }
        }
        catch (Exception exception)
        {
            throw exception;
        }

        return results;
    }
}

我期待REST服务在客户端返回：

enter image description here

但最终，它总是回归：

enter image description here

我该怎么办？请帮忙。

编辑

以下是调用soap服务时的示例响应：

[FaultException: InvalidLogin]
   System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg) +9441823

你看到＆＃34; InvalidLogin＆＃34; ？这就是我想在REST服务的响应中看到的内容来自REST的示例响应：

[WebException: The remote server returned an error: (500) Internal Server Error.]
   System.Net.HttpWebRequest.GetResponse() +6115971

我抛出一个WebFaultException，但我收到WebException 如果我不能在REST上获取确切的错误消息，我会选择SOAP 谢谢你的回答。

Answer 1

使用HttpWebRequest（或Javascript客户端）时，您的自定义异常对它们没有意义。只是Http错误代码（如 500内部服务器错误）和响应内容中的数据。

所以你必须自己处理异常。例如，如果捕获WebException，则可以根据服务器配置读取Xml或Json格式的内容（错误消息）。

catch (WebException ex)
{
    var error = new StreamReader(ex.Response.GetResponseStream()).ReadToEnd();
    //Parse your error string & do something
}

Answer 2

几分钟后我才有类似的问题。也许有帮助。我试图为我的所有服务电话使用扩展程序，如下所示：

以下是 BAD 代码：

public static void ExecuteServiceMethod(this IMyRESTService svc, Action svcMethod)
{ 
    try
    {
       // try to get first last error here
       string lastError = svc.CommHandler.CH_TryGetLastError();
       if (!String.IsNullOrEmpty(lastError))
          throw new WebFaultException<string>(lastError, System.Net.HttpStatusCode.InternalServerError);

       // execute service method
       svcMethod();
    }
    catch (CommHandlerException ex)
    {
       // we use for now only 'InternalServerError'
       if (ex.InnerException != null)
           throw new WebFaultException<string>(ex.InnerException.Message, System.Net.HttpStatusCode.InternalServerError);
       else
           throw new WebFaultException<string>(ex.Message, System.Net.HttpStatusCode.InternalServerError);
     }
     catch (Exception ex)
     {
        throw new WebFaultException<string>(ex.Message, System.Net.HttpStatusCode.InternalServerError);
     }
}

以下是 FIXED 代码：

public static void ExecuteServiceMethod(this IMyRESTService svc, Action svcMethod)
{
    // try to get first last error here
    string lastError = svc.CommHandler.CH_TryGetLastError();
    if (!String.IsNullOrEmpty(lastError))
       throw new WebFaultException<string>(lastError, System.Net.HttpStatusCode.InternalServerError);

    try
    {
       // execute service method
       svcMethod();
    }
    catch (CommHandlerException ex)
    {
       // we use for now only 'InternalServerError'
       if (ex.InnerException != null)
           throw new WebFaultException<string>(ex.InnerException.Message, System.Net.HttpStatusCode.InternalServerError);
       else
           throw new WebFaultException<string>(ex.Message, System.Net.HttpStatusCode.InternalServerError);
     }
     catch (Exception ex)
     {
        throw new WebFaultException<string>(ex.Message, System.Net.HttpStatusCode.InternalServerError);
     }
}

所以......可能你注意到第一个throw被处理到catch (Exception ex)块再次抛出，使其始终显示：'内部服务器错误'。也许它会有所帮助，因为我看到你也有一个全球性的

catch（异常异常）{throw exception; }

可能是它的原因。

Answer 3

1）将faultcontract添加到方法/操作

2）抛出WebFaultException或WebFaultException

3）在客户端捕获webexception然后读取异常响应

catch (WebException exception)
{
var resp = new StreamReader(exception.Response.GetResponseStream()).ReadToEnd();
}

问题陈述中提到的相同问题，能够解决L.B提到的答案，并且其他几个帖子也是如此。所以总结了接下来的步骤

如何处理WebFaultException以返回CustomException？

3 个答案: