RFR: 8057113: (fs) Path should have a method to obtain the filename extension [v7]

[Roger Riggs]

On Tue, 3 May 2022 16:28:14 GMT, Brian Burkhalter <bpb at openjdk.org> wrote:

>> src/java.base/share/classes/java/nio/file/Path.java line 328:
>> 
>>> 326:         String thisExtension = getExtension().orElse(null);
>>> 327:         if (thisExtension == null)
>>> 328:             return Optional.empty();
>> 
>> Maybe keep around the Optional holding the extension to return if it is empty or matches; saving creating a new one.
>
>> Maybe keep around the Optional holding the extension to return if it is empty or matches; saving creating a new one.
> 
> I don't understand this comment. I think that this could be done in the implementation classes but I do not see how to do it here.

Something like:

    default Optional<String> hasExtension(String ext, String... extensions) {
        requireNonNull(ext);
        Optional<String> extension = getExtension();
        String thisExtension = null;
        if (extension.isEmpty() || (thisExtension = extension.get()).equals(ext))
            return extension;
        ...

-------------

PR: https://git.openjdk.java.net/jdk/pull/8066