.NET WebService错误处理设计

Question

I am faced with a design/architectural problem, and can't figure out a clean solution. We have a .NET WebService with hundreds of WebMethods. (See example below). If any of the called WebMethods throws an unhandled exception, we want to generate an email.

Question : What would be a clean design pattern to use in such a situation. I want to avoid inserting repetitive code into hundreds of methods?

[WebService(Namespace = "http://example.com/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
[Serializable]
public class WebService : System.Web.Services.WebService
{
    [WebMethod]
    public string GetQuoteInfo(string request)
    {
        return QuoteService.GetQuoteInfo(request);
    }

    [WebMethod]
    public string GetQuoteAPR(string request)
    {
        return QuoteService.GetQuoteAPR(request);
    }

    [WebMethod]
    public string GetAccountContactInfo(string request)
    {
        return AccountService.GetAccountContactInfo(request);
    }

    ...
    ...
    ...

    [WebMethod]
    public string GetAccountContactInfo(string request)
    {
        // implementation
    }

}

Answer 1

1. Introduce a class that wraps actual method with a try/catch block with proper exception handling.

    public static class InvocationHelper { public static string SafeInvoke(Func<string, string> f, string request) { try { return f(request); } catch(Exception ex) { NofityAboutException(ex); return null; } } } 

2. Modify your WebService methods using that class:

    [WebMethod] public string GetQuoteInfo(string request) { return InvocationHelper.SafeInvoke(r => QuoteService.GetQuoteInfo(r), request); } 

Answer 2

try {

your code here in your web method

    }

    catch (Exception e)
    {

// Email this error message

        e.Message;
        throw;
    }

put it on all your method as there is no way to get perfect error message. its one time work to get error message and you will be free to debug your code every time.

Answer 3

One way would be to use an AOP library such as NConcern . Depending on your scenario it may have some limitations, as the library must be rewritten with CNeptune (see NCover examples).