RFR: 8349910: Implement JEP 517: HTTP/3 for the HTTP Client API [v14]

[Jaikiran Pai]

On Mon, 25 Aug 2025 13:34:51 GMT, Daniel Fuchs <dfuchs at openjdk.org> wrote:

>> Hi,
>> 
>> Please find here a PR for the implementation of [JEP 517: HTTP/3 for the HTTP Client API](https://openjdk.org/jeps/517).
>> 
>> The CSR can be viewed at [JDK-8350588: Implement JEP 517: HTTP/3 for the HTTP Client API](https://bugs.openjdk.org/browse/JDK-8350588)
>> 
>> This JEP proposes to enhance the HttpClient implementation to support HTTP/3.
>> It adds a non-exposed / non-exported internal implementation of the QUIC protocol based on DatagramChannel and the SunJSSE SSLContext provider.
>
> Daniel Fuchs has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 628 commits:
> 
>  - merge latest changes from master branch
>  - http3: minor code cleanup
>  - http3: HeadersLowerCaseTest.java should close the clients it creates
>  - http3: add missing copyright in Http3ConnectionAccess and make the class final
>  - http3: improved test coverage for ImmutableSSLSession
>  - http3: make sure that abandonned HTTP/2 connections are closed
>  - http3: CustomRequestPublisher.java test should take into account server config
>  - Add QUIC support to SunX509 key manager, update copyrights
>  - Move getAlgorithmConstraints to X509KeyManagerCertChecking, update to match surrounding code
>  - Mark H3ErrorHndlingTest as intermittent
>  - ... and 618 more: https://git.openjdk.org/jdk/compare/ae0dac43...719f471d

I haven't reviewed every single file but have reviewed most of those which have the core implementation of this feature. I have skimmed over several of the test files as well. 
This looks good to me.

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Marked as reviewed by jpai (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/24751#pullrequestreview-3155262397