RFR: 8277585: Remove the terminally deprecated finalize() method from javax.imageio.stream APIs

[Brent Christian]

On Tue, 5 Aug 2025 21:17:36 GMT, Phil Race <prr at openjdk.org> wrote:

> This PR removes javax/imageio/stream/ImageInputStreamImpl.finalize()
> As a result, sub-classes which over-ride it to be empty no longer need to do so.
> Also it means that the 2 remaining classes which used it no longer can.
> FileCacheImageOutputStream will have its cache cleaned up by a disposer.
> The impact on applications is that they, or the ImageWriter may need to call flush() IF they relied on finalization.
> However that should be extremely unlikely given that finalization will happen far too late in most cases, and is
> really meant to clean up internal resources.
> The JDK's GIF and TIFF image writers don't flush themselves, so applications which use these together with one of these caching streams would have learned this already.
> 
> The principal outside risk is to 3rd party ImageIO stream subclasses which both allocate native resources and rely on finalization as a backstop clean up in case applications forget to call close. But it will be the applications that are affected if the resource is depleted. 
> The risks of this will be covered in the CSR.
> 
> There's also a lengthy write up in the JBS issue.

Changes requested by bchristi (Reviewer).

src/java.desktop/share/classes/javax/imageio/stream/FileCacheImageOutputStream.java line 275:

> 273:         //cache.close();
> 274:         cache = null;
> 275:         //cacheFile.delete();

Remove commented code?

src/java.desktop/share/classes/javax/imageio/stream/package-info.java line 48:

> 46:  * of sequences of bytes that reduces the amount of internal data copying.
> 47:  * <p>
> 48:  * An {@code ImageInputStream} or {@code ImageInputStream} may internally allocate

"...or Image**Output**Stream..." ?

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PR Review: https://git.openjdk.org/jdk/pull/26650#pullrequestreview-3093759313
PR Review Comment: https://git.openjdk.org/jdk/pull/26650#discussion_r2258082917
PR Review Comment: https://git.openjdk.org/jdk/pull/26650#discussion_r2257961502