RFR: 8377796: java.net.http.HttpClient.send() and sendAsync() never complete when BodyHandler.apply() returns null [v2]

[Daniel Fuchs]

On Thu, 12 Feb 2026 16:16:50 GMT, Jaikiran Pai <jpai at openjdk.org> wrote:

>> Can I please get a review of this change which proposes to address the issue noted in https://bugs.openjdk.org/browse/JDK-8377796?
>> 
>> The change here asserts that if `BodyHandler.apply()` returns `null`, then the HTTP request completes exceptionally. A new test has been introduced to reproduce the issue and verify the fix.
>
> Jaikiran Pai has updated the pull request incrementally with three additional commits since the last revision:
> 
>  - split the test method arguments into individual parts
>  - no need for the duplicate null check
>  - use HttpTestEchoHandler in the new test

LGTM - only one minor remark on the test, and something to investigate further in handleNoBody - but that can be done as a followup.

src/java.net.http/share/classes/jdk/internal/net/http/MultiExchange.java line 387:

> 385:         BodySubscriber<T> bs = responseHandler.apply(new ResponseInfoImpl(r.statusCode(),
> 386:                 r.headers(), r.version()));
> 387:         Objects.requireNonNull(bs, "BodyHandler returned a null BodySubscriber");

We might want to revisit that at some point. Instead of throwing would it make more sense to return a `CompletableFuture` that is completed with a `NullPointerException`? Either way we'll need to see how it behaves WRT operation ref count handling...

test/jdk/java/net/httpclient/NullReturningBodyHandlerTest.java line 204:

> 202:             if (version == Version.HTTP_3) {
> 203:                 builder.setOption(HttpOption.H3_DISCOVERY, HTTP_3_URI_ONLY);
> 204:             }

Should we assert that version == HTTP_2 instead? Since we only use warmup for HTTP/2.

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PR Comment: https://git.openjdk.org/jdk/pull/29691#issuecomment-3895945059
PR Review Comment: https://git.openjdk.org/jdk/pull/29691#discussion_r2803125782
PR Review Comment: https://git.openjdk.org/jdk/pull/29691#discussion_r2803158410