Passing an exception object to a webservice

Question

Following on from a question here got me thinking....

Would it/is it possible that when an application encounters an unhandled exception for this exception object to be serialized and sent to a web service with a db backend. Then, using a utility or even within Visual Studio the exception object could be loaded from the db and inspected??

Would this be at all possible? I guess the first question is whether you can serialize exception objects.

Answer 1

You can serialize exception objects. This is in fact needed to transport an exception object from the server to the client, in the case of an exception being thrown in a web service call. This is why System.Exception has a constructor overload that creates an exception object from serialized data.

Code example for serializing / deserializing exception object:

private static void SerializeException(Exception ex, Stream stream)
{
    BinaryFormatter formatter = new BinaryFormatter();
    formatter.Serialize(stream, ex);
}

private static Exception DeserializeException(Stream stream)
{
    BinaryFormatter formatter = new BinaryFormatter();
    return (Exception)formatter.Deserialize(stream);
}

// demo code
using (Stream memoryStream = new MemoryStream())
{
    try
    {
        throw new NullReferenceException();
    }
    catch (Exception ex)
    {
        // serialize exception object to stream
        SerializeException(ex, memoryStream);
        memoryStream.Position = 0;
    }
    // create exception object from stream, and print details to the console
    Console.WriteLine(DeserializeException(memoryStream).ToString());
}

That being said, I would probably settle for logging the exception type, message and stack trace somewhere so that I can examine the information.

Answer 2

Using WCF, this would be an easy task. Implement a custom IErrorHandler to send errors to a logging service. The FaultException<TDetail> class is used by WCF to report errors in a SOAP XML format and it could be sent directly to the logging service.