RFR: 8371887: HttpClient: SSLParameters with no protocols configured disable HTTP2+ support

[Volkan Yazici]

On Mon, 24 Nov 2025 17:52:54 GMT, Daniel Jeliński <djelinski at openjdk.org> wrote:

> When checking for supported TLS versions, use SSLContext default parameters if the provided SSLParameters have no protocols configured.
> 
> This fixes an issue where using SSLParameters with no protocols disabled the use of HTTP2 and HTTP3, even when these protocols were supported and enabled in the SSLContext.
> 
> Modified the existing tests to additionally cover the case of empty SSLParameters. All tests continue to pass.

src/java.net.http/share/classes/jdk/internal/net/http/HttpClientImpl.java line 472:

> 470:         }
> 471:         sslParams = requireNonNullElseGet(builder.sslParams, sslContext::getDefaultSSLParameters);
> 472:         String[] protocols = sslParams.getProtocols();

This is already a pretty large ctor — can we rename this to `sslProtocols` to ease the cognitive load?

src/java.net.http/share/classes/jdk/internal/net/http/HttpClientImpl.java line 478:

> 476:         if (protocols == null) {
> 477:             // getDefaultSSLParameters.getProtocols should not return null
> 478:             protocols = new String[0];

This can be simplified to:

Suggestion:

            protocols = requireNonNullElseGet(sslContext.getDefaultSSLParameters().getProtocols(), new String[0]);

src/java.net.http/share/classes/jdk/internal/net/http/HttpConnection.java line 1:

> 1: /*

Thank you, this was a long-overdue clean up. 😍 I had an earlier attempt at this in `HttpClientImpl::new`, but did not dare to extend its scope — was told, _"There be dragons!"_ :rofl:

Curious: can we also clean up `QuicClient::requireTLS13` too? Personally, I'm very much in favor of seeing only one occurrence of hardcoded `"TLSv1.2"` and `"TLSv1.3"` string literals.

test/jdk/java/net/httpclient/TlsContextTest.java line 123:

> 121:     }
> 122: 
> 123:     private void runTest(SSLContext context, Version version, String expectedProtocol, boolean setParams) throws Exception {

_Nit:_ `s/setParams/setEmptyParams/`?

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/28480#discussion_r2557696216
PR Review Comment: https://git.openjdk.org/jdk/pull/28480#discussion_r2557698850
PR Review Comment: https://git.openjdk.org/jdk/pull/28480#discussion_r2557710379
PR Review Comment: https://git.openjdk.org/jdk/pull/28480#discussion_r2557721461