ssh in java (run commands on another machine)

Question

I was wondering whether there was a simple way to do this as part of a java program.

I would like to be able to ssh into another machine and perform commands on that machine.

A simple example would be: runtime.exec("say hello world"); would (on a mac) have a text-to-speech engine speak hello world.

Is there a way to have java run this method on another machine?

Also, assuming the above is possible, is there a way to ssh into more than one machine at the same time?

Thanks

Answer 1

There are a lot of libraries to do this. I suggest Ganymed SSH-2 , that is also mentioned in the official OpenSSH website . In the same site, you can also find other libraries that you can use for Java.

This is an example of ls -r command executed via SSH, using Ganymed SSH-2:

import ch.ethz.ssh2.Connection;
import ch.ethz.ssh2.Session;
import ch.ethz.ssh2.StreamGobbler;

[...]

public static ArrayList<String> lsViaSSH(String hostname, String username, String password, String dir) {
    ArrayList<String> ls = new ArrayList<String>();

    try
    {
        Connection conn = new Connection(hostname);

        conn.connect();

        boolean isAuthenticated = conn.authenticateWithPassword(username, password);

        if (isAuthenticated == false) {
            return null;
        }

        Session sess = conn.openSession();

        sess.execCommand("ls -r " + dir);

        InputStream stdout = new StreamGobbler(sess.getStdout());

        BufferedReader br = new BufferedReader(new InputStreamReader(stdout));

        while (true)
        {
            String line = br.readLine();
            if (line == null)
                break;
            ls.add(line);
        }

        sess.close();
        conn.close();
    }
    catch (IOException e)
    {
        return null;
    }

    if(StringUtils.isEmpty(ls.get(0)))
        return null;

    return ls;
}

This is not the only function needed in order to execute a command via SSH, but I hope it could be a good starting point for you.

Answer 2

Have a look at JSch

As far as executing at the exact same time? Not really unless you intend to spawn multiple threads to deal with your list of remote machines.

Answer 3

鉴于您所在的系统中ssh命令可用，并且设置了ssh密钥以避免输入密码，最简单的只是

runtime.exec("ssh remote_comp 'say hello world'");

Answer 4

我建议你看一下Apache MINA SSHD ，它可以用java写一个客户端和一个服务器