How to SFTP when SSH is disabled

My company has disabled SSH, but allows SFTP.

For example, "sftp" commands will work but "ssh" will not.

They may have configured something like this in "/etc/ssh/sshd_config":

```
Match Group sftp-only
ForceCommand internal-sftp
ChrootDirectory /pub/sftp
PermitTunnel no
AllowAgentForwarding no
AllowTcpForwarding no
X11Forwarding no
```

The typical pattern does not work:

```
import net.schmizz.sshj.*;

...

void connect() {
SSHClient sshClient;
SFTPClient sftpClient;

sshClient = new SSHClient();
sshClient.connect(hostname, port); // Port = 2233
sshClient.authPublickey(username, privatekey);
sftpClient = sshClient.newSFTPClient();
}
```

The above code throws an exception at "sshClient.connect()":

```
Exception in thread "main" java.net.ConnectException: Connection refused (Connection refused)
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:589)
at net.schmizz.sshj.SocketClient.connect(SocketClient.java:126)
```

Is there a way to get a SFTP implementation without instantiating SSHClient ?

Or does anybody know of a solution (or have I misunderstood something) ?