RFR: 8368695: Support 101 switching protocol in jdk.httpserver [v3]

[Daniel Fuchs]

On Fri, 10 Oct 2025 21:22:49 GMT, Josiah Noel <duke at openjdk.org> wrote:

>> - adds a flag to ExchangeImpl to signal whether the current request is an Upgrade request
>> - Adds a new `UpgradeInputStream` to ensure that the server keeps track of when the upgraded request is closed
>> - on 101 response codes, `sendResponseHeaders` will not immediately close the output stream 
>> - on 101 response codes, `sendResponseHeaders` will use an `UndefLengthOutputStream`
>
> Josiah Noel has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Update UpgradeInputStream.java

But that would be an incompatible change, isn't it?

Consider the following:


httpserver.createContext("/echo/", (exch) -> {
   byte[] bytes;
   try (var is = exch.getRequestBody()) { bytes = is.readAllBytes(); }
   exch.sendResponseHeaders(200, bytes.length == 0 ? -1  : bytes.length);
   try (var os = exch.getResponseBody()) { if (bytes.length > 0) os.write(bytes); } 
});


wouldn't that now block forever if the request contains an upgrade header?

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PR Comment: https://git.openjdk.org/jdk/pull/27751#issuecomment-3402699078