unable to understand connection establishment code

Question

I am beginner in Java and as such I am having difficulty in understanding a piece of code.At this SO post the first two lines create a connection instance:

/* Create a connection instance */
Connection conn = new Connection(hostname);
/* Now connect */
conn.connect();

I am unable to get which library needs to be imported to support this? The post mentions use of JSch in the beginning but when I tried it then I couldn't where in JSch Connection class is declared? Any help will be useful for me.

If you want to learn how to create a database connection, I would go to a more basic source, such as this: http://docs.oracle.com/javase/tutorial/jdbc/basics/connecting.html — Al Lelopath, Aug 25 '14 at 22:52
@mickey is that a database connection? The post is related to remote execution of R scripts — Jason Donnald, Aug 25 '14 at 22:53
My mistake, your example is connect to a remote server, not a db. — Al Lelopath, Aug 25 '14 at 22:54
@mickey in that regards only how does `Connection` is imported? — Jason Donnald, Aug 25 '14 at 22:55
There seem to be two or three different things called Jsch. Keep looking. — user207421, Aug 25 '14 at 23:08
@EJP I looked around Jsch but all I found is the `jcraft` one which I tried but was unable to create `Connection` instance — Jason Donnald, Aug 25 '14 at 23:24
Well I looked around too and I found two or three. Obviously the jcraft one isn't the right one. Keep looking. If I found more, you can. — user207421, Aug 26 '14 at 00:04

score 2 · Accepted Answer · edited May 23 '17 at 11:49

JCraft JSCH can be used to perform SFTP and run remote commands with an SSH connection.

It does not use a Connection class. In JSCH you create a Session object, which contains connection information. You then connect the session object, then create Channel objects to send input/receive output.

Here is the session API documentation for JSCH.

Here are some examples from JCraft.

There have been quite a few JSCH questions asked here on Stack overflow, some of which include working code you could use to try it out.

score 0 · Answer 2 · answered Aug 26 '14 at 07:55

0

I would guess that the Connection class you mention is ch.ethz.ssh2.Connection. It's mentioned in import directives in code samples here and here. This class looks to be in a JAR named ganymed-ssh2.jar.

answered Aug 26 '14 at 07:55

Luke Woodward

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The poster in the linked question states he is using something called Jsch. Ganymed is a good SSH library, and it does have a Connection class, but it isn't called Jsch. – user207421 Aug 26 '14 at 08:13
@EJP: The class I linked to has the constructor and all methods mentioned in the code sample in the linked question, and the [Session](http://www.ganymed.ethz.ch/ssh2/javadoc/ch/ethz/ssh2/Session.html) class also has the methods mentioned in that code sample. So I believe that the Ganymed library is being used. Perhaps the poster in the linked question was mistaken about using JSch? – Luke Woodward Aug 26 '14 at 08:31

unable to understand connection establishment code

2 Answers2