RFR: 8371903: HttpClient: improve handling of HTTP/2 GOAWAY frames with error code [v7]

[Christoph Läubrich]

On Mon, 15 Dec 2025 13:24:27 GMT, Jaikiran Pai <jpai at openjdk.org> wrote:

> The API specification of HttpClient for send/sendAsync currently only specify IOException with no specific expectations of HTTP protocol specific exception types

Even though its nice do document all possible subtypes I think its not specifically forbidden (or can be enforced) and there is at least on precedence with `HttpTimeoutException` (and I can think of many more e.g EOFException in general) and `jdk.internal.net.http.common.Utils.toConnectException(Throwable)` even checks for some of those already (and I see none of those explicitly documented).

So I think it not necessarily requires a specification change, for a first step it could even be non public internal types like `jdk.internal.net.http.common.ConnectionExpiredException`.

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PR Review Comment: https://git.openjdk.org/jdk/pull/28632#discussion_r2619659317