Return HTTP Status Codes from ASP.NET Core Methods
In this article, we will see how to return HTTP Status codes in .NET Core methods based on the HTTP Operation in API.
We shall also see the most commonly asked format like returning HTTP Status code 500 Internal server error etc.
We will cover the below aspects in today’s article,
Example: One may return Web API with ASP.NET Core MVC 200, 500, or 503 error codes
RESTFul services principle talks about HTTP Status code and their usage.
It’s important to follow these REST HTTP Status codes appropriately when following REST specifications.
.NET Core has inbuilt support for all basic HTTP Status codes and they are easy to configure for almost all standard HTTP status codes.
RFC7231 defines the specification for this HTTP Status code in detail.
References:
RFC7807 defines the specification for error response for HTTP error operation
References:
Built-in HTTPS Status Code for .NET Core
Please note that ASP.NET core provides built-in support for both RFC7231 and RFC7807, giving you direct capability on returning the standards HTTP status code plus additional details in case of error operations based on RFC specifications.
HTTP Status Code – 200 (OK)
If your controller method returns IActionResult,
What is HTTP Status Ok or 200?
- The HTTP 200 (OK) status code indicates success.
- This response also meant the response has the payload.
- If no payload is desired, the server should send a 204 (NoContent) status code.
One can use the built-in type Ok() as below,
[HttpGet]
public IActionResult GetSynchrounous(string id)
{
Book book = null;
//run method - Synchronously
book = _bookService.Get(id);
return Ok(book);
}
This built-in type does support sending additional details with its overloaded API.
Please do leverage those when required.
HTTP Status Code – 400 (Bad Request)
This status code means the server cannot process the request due to malformed requests, invalid requests, etc.
One can use the built-in type BadRequest() as below,
Example:
[HttpGet("book/{id}")]
public IActionResult GetAccount(string id)
{
if (id == null)
{
return BadRequest();
}
return Ok();
}
Below is the response for the above request (Using Chrome) will produce Status Code: 400 Bad Request,
Request URL: http://localhost:60213/api/books/book/1
Request Method: GET
Status Code: 400 Bad Request
Remote Address: [::1]:60213
Referrer Policy: no-referrer-when-downgrade
This built-in type does support sending additional details with its overloaded API.
The below response is based on RFC7807 which is a specification around how to use ProblemDetails.
Note: Controller method returning IActionResult has built-in supported Error response based on the RFC7807 Porblem details specifications.
HTTP Status Code – 500 (InternalServerError )
This status code means the server encountered an unexpected condition that prevented it from fulfilling the input request.
- Use built-in type StatusCode()
- Use Problem() or ProblemDetails() as per RFC7807
Return HTTP 500 using the Status code
Return HTTP 500 using the Status code below,
public IActionResult GetAccount1(string id)
{
Book book = null;
try
{
//run method - Synchronously
book = _bookService.Get(id);
if (book == null)
{
return NotFound();
}
book.Price = 10;
}
catch (Exception ex)
{
return StatusCode(500, "Internal Server Error. Something went Wrong!");
}
return Ok(book);
Using ProblemDetails and Best practices
You can return the HTTP status code using ProblemDetails. Kindly visit the below guidelines for more details,
Return HTTP 500 using ProblemDetails,
catch (Exception ex)
{
return Problem("Internal Server Error.Something went Wrong!");
}
Below is the response for the above request (Using Chrome) which produces Status Code: 500 Internal Server Error
Client-side,
{
"type": "https://tools.ietf.org/html/rfc7231#section-6.6.1",
"title": "An error occured while processing your request.",
"status": 500,
"detail": "Internal Server Error.Something went Wrong!",
"traceId": "|5b367172-44fadfb7f6df04a9."
}
This built-in type does support sending additional details with its overloaded API.
- StatusCode( int statusCode, object value);
- StatusCode( int statusCode);
StatusCode can be used as an alternative for all other HTTP status codes where the built-in type is missing.
StatusCode class caN be used for all below-supported codes,
public static class StatusCodes
{
public const int Status100Continue = 100;
public const int Status412PreconditionFailed = 412;
public const int Status413PayloadTooLarge = 413;
public const int Status413RequestEntityTooLarge = 413;
public const int Status414RequestUriTooLong = 414;
public const int Status414UriTooLong = 414;
public const int Status415UnsupportedMediaType = 415;
public const int Status416RangeNotSatisfiable = 416;
public const int Status416RequestedRangeNotSatisfiable = 416;
public const int Status417ExpectationFailed = 417;
public const int Status418ImATeapot = 418;
public const int Status419AuthenticationTimeout = 419;
public const int Status421MisdirectedRequest = 421;
public const int Status422UnprocessableEntity = 422;
public const int Status423Locked = 423;
public const int Status424FailedDependency = 424;
public const int Status426UpgradeRequired = 426;
public const int Status428PreconditionRequired = 428;
public const int Status429TooManyRequests = 429;
public const int Status431RequestHeaderFieldsTooLarge = 431;
public const int Status451UnavailableForLegalReasons = 451;
public const int Status500InternalServerError = 500;
public const int Status501NotImplemented = 501;
public const int Status502BadGateway = 502;
public const int Status503ServiceUnavailable = 503;
public const int Status504GatewayTimeout = 504;
public const int Status505HttpVersionNotsupported = 505;
public const int Status506VariantAlsoNegotiates = 506;
public const int Status507InsufficientStorage = 507;
public const int Status508LoopDetected = 508;
public const int Status411LengthRequired = 411;
public const int Status510NotExtended = 510;
public const int Status410Gone = 410;
public const int Status408RequestTimeout = 408;
public const int Status101SwitchingProtocols = 101;
public const int Status102Processing = 102;
public const int Status200OK = 200;
public const int Status201Created = 201;
public const int Status202Accepted = 202;
public const int Status203NonAuthoritative = 203;
public const int Status204NoContent = 204;
public const int Status205ResetContent = 205;
public const int Status206PartialContent = 206;
public const int Status207MultiStatus = 207;
public const int Status208AlreadyReported = 208;
public const int Status226IMUsed = 226;
public const int Status300MultipleChoices = 300;
public const int Status301MovedPermanently = 301;
public const int Status302Found = 302;
public const int Status303SeeOther = 303;
public const int Status304NotModified = 304;
public const int Status305UseProxy = 305;
public const int Status306SwitchProxy = 306;
public const int Status307TemporaryRedirect = 307;
public const int Status308PermanentRedirect = 308;
public const int Status400BadRequest = 400;
public const int Status401Unauthorized = 401;
public const int Status402PaymentRequired = 402;
public const int Status403Forbidden = 403;
public const int Status404NotFound = 404;
public const int Status405MethodNotAllowed = 405;
public const int Status406NotAcceptable = 406;
public const int Status407ProxyAuthenticationRequired = 407;
public const int Status409Conflict = 409;
public const int Status511NetworkAuthenticationRequired = 511;
}
Unhandled exception in API Pipeline?
It’s recommended to use the Global exception middleware or handler approach for any unhandled exception in the API pipeline.
Users should vary on what exception should reach the consumer as a business exception Vs what can be logged in the form of technical server logging.
Kindly see below the reference article on best practices of exception handling,
Do you have any comments or ideas or any better suggestions to share?
Please sound off your comments below.
Happy Coding !!
References :
Summary
It’s important to follow HTTP Status codes appropriately when following REST specifications for any communication between the client and servicer.
Today we learned that .NET Core has provided support for using almost all HTTP status codes allowing us to follow specifications and principles around the same based on standards RFC guidelines.
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Awesome. Very helpful
Thanks Ashu for your feedback.