public static void UseExceptionHandlerMiddleware(this IApplicationBuilder builder)
{
builder.Run(async context =>
{
var errorFeature = context.Features.Get <IExceptionHandlerFeature>();
var exception = errorFeature.Error;
if (exception is DomainException)
{
var domainException = exception as DomainException;
context.Response.StatusCode = StatusCodes.Status400BadRequest;
context.Response.ContentType = "application/json";
var error = new DomainExceptionContract()
{
Key = domainException.Key,
Message = domainException.Message
};
await context.Response.WriteAsync(error.ToString());
}
else if (exception is ForbiddenException)
{
context.Response.StatusCode = StatusCodes.Status403Forbidden;
context.Response.ContentType = "application/json";
var error = new DomainExceptionContract()
{
Key = "Forbidden",
Message = "Forbidden"
};
await context.Response.WriteAsync(error.ToString());
}
else
{
var loggerFactory = builder.ApplicationServices.GetService(typeof(ILoggerFactory)) as ILoggerFactory;
var exceptionLogger = loggerFactory.CreateLogger(typeof(ExceptionHandlerMiddlewareExceptions));
exceptionLogger.LogError(exception, "Exception");
context.Response.StatusCode = StatusCodes.Status500InternalServerError;
}
});
}
public async Task Invoke(HttpContext context)
{
try
{
await _next(context);
}
catch (DomainException domainException)
{
var error = new DomainExceptionContract()
{
Key = domainException.Key,
Message = domainException.Message
};
_logger.LogError(domainException, domainException.Message);
await WriteErrorMessageToResponse(context, HttpStatusCode.BadRequest, error);
}
catch (ForbiddenException)
{
var error = new DomainExceptionContract()
{
Key = "Forbidden",
Message = "Forbidden"
};
await WriteErrorMessageToResponse(context, HttpStatusCode.Forbidden, error);
}
catch (Exception ex)
{
var error = new DomainExceptionContract()
{
Key = "InternalServerError",
Message = ex.Message
};
_logger.LogError(ex, ex.Message, new object[] { });
await WriteErrorMessageToResponse(context, HttpStatusCode.InternalServerError, error);
}
}
private async Task WriteErrorMessageToResponse(HttpContext context, HttpStatusCode httpStatusCode, DomainExceptionContract error)
{
context.Response.Headers[HeaderNames.CacheControl] = "no-cache";
context.Response.Headers[HeaderNames.Pragma] = "no-cache";
context.Response.Headers[HeaderNames.Expires] = "-1";
context.Response.Headers.Remove(HeaderNames.ETag);
var result = JsonConvert.SerializeObject(error);
context.Response.ContentType = "application/json";
context.Response.StatusCode = (int)httpStatusCode;
await context.Response.WriteAsync(result);
}
