FileVisitor / Are we feature frozen yet?

Ben Evans benjamin.john.evans at
Tue Aug 6 15:00:55 UTC 2013

On Files?

Yes, that does indeed look suspiciously like it'll cover the current use
cases I have. Let me check & come back if not.


On Tue, Aug 6, 2013 at 3:15 PM, Alan Bateman <Alan.Bateman at>wrote:

> On 06/08/2013 06:39, Ben Evans wrote:
>> Hi,
>> I have a suggestion for a point lambdafication change which I don't think
>> anyone's proposed yet. (As usual, if my Google-fu has failed me, please
>> point me at the relevant discussion).
>> In java.nio.file we have the FileVisitor interface, which defines 4
>> methods.
>> We also have the SimpleFileVisitor class which defines sane (basically
>> no-op) implementations of all the methods.
>> In using FileVisitor, I've noticed that visitFile() tends to be overridden
>> / used far more often than the others. It would be nifty if it we could
>> lambdify in such a way that a lambda expression could be fed to
>> Files.walkFileTree().
>> Could we add default implementations to FileVisitor (those from
>> SimpleFileVisitor seem reasonable) for all methods except visitFile() ?
>> This would then make code like this possible:
>> Path homeDir = Paths.get("/Users/kittylyst");
>> Files.walkFileTree(homeDir, (p, attrs) ->  {
>> System.out.println(p.**getFileName()); return FileVisitResult.CONTINUE;
>> });
>> I have a patch which demonstrates this - let me know if there's potential
>> here, and if anyone would be interested in sponsoring the patch.
>>  Have you looked at the walk and find methods? (They currently return a
> CloseableStream but there is discussion on just returning a Stream).
> -Alan.

More information about the core-libs-dev mailing list