RFR: 8349910: Implement HTTP/3 for the HTTP Client API

[Chen Liang]

On Tue, 22 Apr 2025 18:18:51 GMT, Daniel Fuchs <dfuchs at openjdk.org> wrote:

>> src/java.net.http/share/classes/java/net/http/HttpRequest.java line 357:
>> 
>>> 355:          * @since TBD
>>> 356:          */
>>> 357:         public default <T> Builder setOption(HttpRequestOption<T> option, T value) { return this; }
>> 
>> Bikeshed: we usually omit the set prefix for builders.
>
> I actually hesitated quite a bit on this one. We have a precedent with `Builder.setHeader(name, value)` - where the `setHeader` method replaces any value associated with the name with the given value, while `header(name, value)` would just add another value to the list of values associated with the name. I didn't want to give the impression that you could provide several values to the same option - and thus opted for naming that method `setOption`. I could let me be convinced to rename it if there is a strong concensus.

Didn't notice we already use `set` prefix in this builder. All good; consistency is more important.

>> src/java.net.http/share/classes/java/net/http/HttpResponse.java line 937:
>> 
>>> 935:                 HttpRequest initiatingRequest,
>>> 936:                 HttpRequest pushPromiseRequest,
>>> 937:                 PushId pushid,
>> 
>> (Warning: I know little about HTTP, my assumptions and thus whole argument may be invalid below!)
>> 
>> This feels like users need to use push ids as units of synchronization on this handler, such as tracking this with a ConcurrentHashMap.
>> 
>> Is it possible for users to instead provide a `Function<PushId, PushPromiseHandler>` in `HttpClient::sendAsync`? I think this might make it easier for users as they no longer need to think about concurrency for different ids.
>
> PushId is an HTTP/3 concept. It would be strange to have a generic method (sendAsync) that you could call with any requests, but with a parameter that could only be used for HTTP/3. We don't have pushIds for HTTP/2. I don't think we would want to take this route.

Do users need to track the push ids in a thread-safe data structure like ConcurrentHashMap in a PushPromiseHandler?

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PR Review Comment: https://git.openjdk.org/jdk/pull/24751#discussion_r2054677703
PR Review Comment: https://git.openjdk.org/jdk/pull/24751#discussion_r2054679688