RFR: 8350880: (zipfs) Add support for read-only zip file systems [v4]

[David Beaumont]

On Fri, 16 May 2025 14:37:28 GMT, Jaikiran Pai <jpai at openjdk.org> wrote:

>> David Beaumont has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Changes based on review feedback.
>
> src/jdk.zipfs/share/classes/jdk/nio/zipfs/ZipFileSystem.java line 241:
> 
>> 239:         this.readOnly = forceReadOnly || multiReleaseVersion.isPresent() || !Files.isWritable(zfpath);
>> 240:         if (readOnly && accessMode == AccessMode.READ_WRITE) {
>> 241:             String reason = Files.isWritable(zfpath)
> 
> Nit - this additional call to Files.isWritable(...) can be avoided if we store the value of the previous call (a couple of lines above). I realize that the previous `Files.isWritable` is stashed at the end of the `||` conditionals to prevent it from being invoked in certain situations.
> 
> So maybe a better change would be something like:
> 
> 
> String reason = multiReleaseVersion.isPresent()
>    ? "A multi-release JAR file opened with a specified version is not writable"
>    : "The underlying ZIP file is not writable";
> 
> 
> which would then avoid any additional calls to `Files.isWritable`.

Done.

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PR Review Comment: https://git.openjdk.org/jdk/pull/25178#discussion_r2095532769