[4.x] Missing Http Status codes for 421...429,431,451

[rob-bygrave]

Environment Details

• Helidon Version: 4.0-M1
• Helidon SE
• JDK version: 20
• OS: MacOS

---

Problem Description

io.helidon.common.http.Http.Status has public static fields for the Http status codes. In the 400 range it stops at 418 and the status codes for 421, 422, 423 ... 429, 431, 451 are missing.

Refer: https://github.com/helidon-io/helidon/blob/main/common/http/src/main/java/io/helidon/common/http/Http.java#L551

Suggested fix

Add entries in https://github.com/helidon-io/helidon/blob/main/common/http/src/main/java/io/helidon/common/http/Http.java for the status codes: 421, 422, 423 ... 429, 431, 451

[tomas-langer]

I am not for including every code listed - the codes we have in Helidon are part of specifications. It would be nice to have a clear understanding which RFC defines that status code.
For example 421, 422, 426 are part of RFC 9110
428, 429 etc. are part of RFC 6585 which seems to be a "proposed standard" (not final stage)
451 - RFC 7725 (although I like the Monty Python reference, not sure this is a widely used code - some investigation required)

[tomas-langer]

A reasonable list of status codes: https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/451

[rob-bygrave]

I am not for including every code listed

FWIW I'm fine with not adding them all. The missing codes I expect to use myself and would really love to see added are 422, 423, 429 and maybe 428.

• 422 Unprocessable Content (Typically a validation error on the input content)
• 423 Locked
• 429 Too Many Requests

With these 3 added (plus maybe 428?) I'd be content.

FYI: Background motivation:
There is a performance benefit of using the pre-defined Http.Status values plus some documentation benefit for people reading the code rather than seeing an int value. I have code generation library (annotation processor) that will use the pre-defined Http.Status if they exist.

Edit:
BTW I really love the codes having the reason PLUS code like OK_200, CONFLICT_409 etc. I think that is really nice in the way it will assist devs less familiar with the http status codes learn and understand them - a really nice little touch imo.

[rob-bygrave]

Reference links that might help via https://www.iana.org/assignments/http-status-codes/http-status-codes.xhtml with the status codes and related RFC

• https://www.rfc-editor.org/rfc/rfc9110.html#section-15.5.21
• https://www.rfc-editor.org/rfc/rfc4918.html#section-11.3
• https://www.rfc-editor.org/rfc/rfc6585.html#section-4

[tomas-langer]

I have added the requested statuses, PR is ready.