RFR: 8331195: Improve com.sun.net.httpserver.HttpExchange usability

[Daniel Fuchs]

On Tue, 4 Nov 2025 14:10:14 GMT, Michael McMahon <michaelm at openjdk.org> wrote:

> I'd like to return to this issue with a new PR that addresses the usability issue minimally. Namely to define numeric constants
> for the counter-intuitive responseLength values in `HttpExchange.sendResponseHeaders`. The apidoc then refers to the constant names rather than the numeric values.
> 
> I've updated the implementation and some tests (though not all yet) to use the constant names. I'm open to suggestions on the names themselves. Once that is agreed, I'll update the remaining tests and any other call sites in the implementation.
> 
> Thanks,
> Michael

This is a good idea, but it kind of hides the fact that passing 0 may not do what you think it does. 

Typically the pitfall is to assume that if you have an array of bytes then you can can call `sendResponseHeaders` with the array length. The API doc of `sendResponseHeaders` should probably make it clear that 0 is a special value, and that `RSPBODY_CHUNKED` is 0. 

In addition I would suggest adding code snipets showing both cases (one using a byte array and passing `bytes.length == 0 ? RSPBODY_EMPTY : bytes.length` and the other using `RSPBODY_CHUNKED` with e.g. transferring the content of an `InputStream`.

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PR Comment: https://git.openjdk.org/jdk/pull/28132#issuecomment-3486767513