Add recursive list support for remote file sessions

[artembilan]

Something like list(String path, boolean recurse) to Session would be a good API delegated from the AbstractInboundFileSynchronizer.transferFilesFromRemoteToLocal() when we would like to deal not only with the top-level files in the remote directory, but also pull files from sub-directories.

[superlins]

I am really looking forward to this feature, even though I have currently implemented recursive fetching of remote directories through a custom file synchronizer.

[superlins]

I found mina-sshd-sftp like below, help useful!

[artembilan]

I think you are right and we definitely can use that SftpClientDirectoryScanner in the list(String path, boolean recurse) API we propose for this fix.
The pattern matching is out of scope for this feature since it is already covered by our FileListFilter API which is applied immediately after fetching remote entries in the transferFilesFromRemoteToLocal().
The FTP and SMB parts need to be investigated individually.