Files.createFile() makes use of newByteChannel(); what if the fs does _not_ support .newByteChannel()?

[Alan Bateman]

On 16/12/2015 13:44, Francis Galiegue wrote:
> Hello,
>
> All is in the question really...
>
> The javadoc of .newByteChannel() on the provider says that
> UnsupportedOperationException will be thrown if one OpenOption is not
> supported, but since the filesystems I develop cannot return any
> meaningful form of SeekableByteChannels at all, I always throw
> UnsupportedOperationException...
The original intention was that all providers must implement 
newByteChannel and the open options listed in the table. In the 
degnerative case then the underlying file system should at least support 
reading a file sequentially, or when it's a read-write file system that 
is supports writing to a file sequentially. Seeking might mean the 
position(long) method fails of course. Also Files.create is specified to 
be atomic with respect to other file system operations and that might be 
challenge too. It would be good if the javadoc could specify the 
absolute minimum but the original intention was not that newByteChannel 
always throws UOE.

-Alan.