HOW TO CATCH ALL EXCEPTIONS IN WEB API 2?

Ashish Pandey

Total Post:128

Points:898
Posted by  Ashish Pandey
 1029  View(s)
Ratings:
Rate this:

I'm writing a RESTful API in Web API and I'm not sure how to handle errors effectively. I want the API to return JSON, and it needs to consist of the exact same format every single time - even on errors. Here are a couple of examples of what a successful and a failed response might look like.

Success:

{

    Status: 0,

    Message: "Success",

    Data: {...}

}

Error:

{

    Status: 1,

    Message: "An error occurred!",

    Data: null

}

If there is an exception - any exception at all, I want to return a response that is formed like the second one. What is the foolproof way to do this, so that no exceptions are left unhandled?

  1. Manoj Bhatt

    Post:154

    Points:1086
    Re: How to catch all exceptions in Web API 2?

    Implement IExceptionHandler.

    Something like:

    public class APIErrorHandler : IExceptionHandler

    {

        public Task HandleAsync(ExceptionHandlerContext context, CancellationToken cancellationToken)

        {

            var jsonResult = Json.Encode(new

                                    {

                                        Message = new { Message = context.Exception.Message },

                                        Status = ... // whatever,

                                        Data = ... // whatever

                                    });

     

            context.Result = new ResponseMessageResult(new HttpResponseMessage { StatusCode = HttpStatusCode.InternalServerError, Content = new StringContent(jsonResult) });

     

            return Task.FromResult(0);

        }

    }

    and in the configuration section of WebAPI (public static void Register(HttpConfiguration config)) write:

    config.Services.Replace(typeof(IExceptionHandler), new APIErrorHandler());

Answer

NEWSLETTER

Enter your email address here always to be updated. We promise not to spam!