Convert from FTP to SFTP

Question

I have the below code which works for FTP. How do I make it to work for SFTP

((ChannelExec) channel).setCommand(cmd);
channel.setXForwarding(true);
channel.setInputStream(System.in);
InputStream in=channel.getInputStream();
channel.connect();
return in;

I know that I need to use ChannelSftp instead of Channel class, but I get type cast error in the setcommand line. Cannot cast type ChannelSftp to ChannelExec

possible duplicate of http://stackoverflow.com/questions/14617/java-what-is-the-best-way-to-sftp-a-file-from-a-server — M. Abbas, Oct 03 '13 at 12:16
What is that command? Is it an FTP command you are trying to use with SFTP? (sorry, don't know that lib) — Maxime Chéramy, Oct 03 '13 at 12:18
cmd will be passed on as a parameter. It could be "top" for example — MansoorShaikh, Oct 03 '13 at 12:21

score 1 · Answer 1 · edited May 23 '17 at 12:13

The first thing to understand is SFTP is different than FTP or FTP/s. SFTP works off of SSH whereas FTP/s uses SSL.

That being said, JSCH provides a pretty straight forward way to use SFTP, including setting X forwarding. Take a look at the examples as well as the linked question from mabbas.

Based upon your comment, it appears that you actually want a remote shell to be invoked/executed against, try the following to see if it'll do what you need:

//connect to the remote shell
Channel channel=session.openChannel("shell");
((ChannelShell)channel).setAgentForwarding(true);
channel.setInputStream(System.in); //Send commands here
channel.setOutputStream(System.out); //output responses here      
channel.connect();

You won't be able to use ChannelSftp as it does not have a setCommand or exec method

What is the difference between this code and the code I posted. — MansoorShaikh, Oct 03 '13 at 12:33

score 0 · Answer 2 · answered Oct 03 '13 at 14:04

If you're using JSCH, they have several example programs which illustrate how to use the library. The SFTP client example illustrates how to open an SFTP session.

Session session=jsch.getSession(user, host, port);
...
session.connect();

Channel channel=session.openChannel("sftp");
channel.connect();
ChannelSftp c=(ChannelSftp)channel;

That's all you have to do. ChannelSftp contains functions to send and receive files, get file listings, and so on. You don't have to access the channel's input or output streams.

Convert from FTP to SFTP

2 Answers2