Why does Path check for the Default FileSystem?

[Michael Hall]

> On Mar 23, 2021, at 8:41 AM, Alan Bateman <Alan.Bateman at oracle.com> wrote:
> 
> On 23/03/2021 13:36, Michael Hall wrote:
>> May I ask why the default FileSystem is checked for here?
>> 
>> default File toFile() {
>>         if (getFileSystem() == FileSystems.getDefault()) {
>>             return new File(toString());
>>         } else {
>>             throw new UnsupportedOperationException("Path not associated with "
>>                     + "default file system.");
>>         }
>>     }
>> 
>> For my custom DefaultFileSystemProvider I found it necessary to have my own Path class.
>> Most of mine is passthrough and for the Path class I keep a proxy platform provider Path that I use for almost all functionality.
>> This check now seems to fail this?
>> Is it necessary to be the default or would also being for the default ‘file’ scheme be good enough?
> A java.io.File cannot represent a file in a custom file system.
> 
> If you are running into an issue here then it may suggest that you aren't wrapping or unwrapping correctly. What does Path::getFileSystem return on your Path implementation?
> 
> -Alan

us.hall.trz.osx.MacFileSystem at 4e0e2f2a

My own Default one. Maybe custom is the wrong word and means something else.

My Default Path class has…

    @Override
    public final File toFile() {
    	return proxy.toFile();
    }

Where proxy is an instance for the same file obtained using the platform provider. The code as-is objects to me falling back to this Path provider. Which effectively makes passthrough impossible.