Java: JschSample01.java

import java.io.IOException;
import java.io.InputStream;

import com.jcraft.jsch.Channel;
import com.jcraft.jsch.ChannelExec;
import com.jcraft.jsch.JSch;
import com.jcraft.jsch.JSchException;
import com.jcraft.jsch.Session;

public class Exec {

    public static void test(Session session) throws Exception {
        Channel channel = session.openChannel("exec");
        ((ChannelExec) channel).setCommand("pwd");

        channel.setInputStream(null);

        ((ChannelExec) channel).setErrStream(System.err);

        InputStream in = channel.getInputStream();

        channel.connect();

        byte[] tmp = new byte[1024];
        while (true) {
            while (in.available() > 0) {
                int i = in.read(tmp, 0, 1024);
                if (i < 0)
                    break;
                System.out.print(new String(tmp, 0, i));
            }
            if (channel.isClosed()) {
                System.out.println("exit-status: " + channel.getExitStatus());
                break;
            }
            try {
                Thread.sleep(1000);
            } catch (Exception ee) {
            }
        }
        channel.disconnect();
    }

    public static void main(String[] arg) {
        try {
            JSch jsch = new JSch();         
            Session session = jsch.getSession("nck", "127.0.0.1", 22);          
            session.setPassword("asd");         
            session.setConfig("StrictHostKeyChecking", "no");           
            session.connect();

            test(session); // This one succeeds with exit-status: 0         
            test(session); // This one fails with exit-status: 255

            session.disconnect();
        } catch (Exception e) {
            //
        }
    }
}

Java: JschSample02.java

/**
 * Run several ssh commands in a single JSch session
 */
import com.jcraft.jsch.Channel;
import com.jcraft.jsch.JSch;
import com.jcraft.jsch.Session;
import java.io.*;

class SshMultiCommands
{
   public static void main(String[] args) throws Exception
   {
      JSch jsch = new JSch();
      String user = "user";            //CHANGE ME
      String host = "192.168.222.157"; //CHANGE ME
      String passwd = "password";      //CHANGE ME
      int port = 22;    
      Session session = jsch.getSession(user, host, port);
      session.setPassword(passwd);

      session.setConfig("StrictHostKeyChecking", "no");

      session.connect();

      Channel channel = session.openChannel("shell");
      OutputStream ops = channel.getOutputStream();
      PrintStream ps = new PrintStream(ops, true);

      channel.connect();
      InputStream input = channel.getInputStream();

      //commands
      ps.println("ls -lag");
      ps.println("cd /etc");
      ps.println("ls");
      ps.println("exit");
      ps.close();

      printResult(input, channel);

      channel.disconnect();
      session.disconnect();
   }

   /**
    * @param input
    * @param channel
    */
   private static void printResult(InputStream input,
                                   Channel channel) throws Exception
   {
      int SIZE = 1024;
      byte[] tmp = new byte[SIZE];
      while (true)
      {
         while (input.available() > 0)
         {
            int i = input.read(tmp, 0, SIZE);
            if(i < 0)
               break;
             System.out.print(new String(tmp, 0, i));
         }
         if(channel.isClosed())
         {
            System.out.println("exit-status: " + channel.getExitStatus());
            break;
         }
         try
         {
            Thread.sleep(300);
         }
         catch (Exception ee)
         {
         }
      }
   }
}

Java: JschSample03.java

package examples.com;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

import com.jcraft.jsch.Channel;
import com.jcraft.jsch.ChannelExec;
import com.jcraft.jsch.JSch;
import com.jcraft.jsch.JSchException;
import com.jcraft.jsch.Session;

public class TempFile {

private static Session connectSession(String userName, String password, String host) throws Exception {
        JSch.setLogger(new MyLogger());
        JSch jsch = new JSch();
        Session session = null;
        try {
            session = jsch.getSession(userName, host, 22);
            session.setPassword(password);
            session.setTimeout(10000);
            java.util.Properties config = new java.util.Properties();
            config.put("StrictHostKeyChecking", "no");
            session.setConfig(config);
            session.connect();                      
        }
        catch (JSchException ex) {
            System.out.println(ex);
        }
        return session;
    }

    private static void connectChannel(Session session, String command) throws JSchException, IOException {
        System.out.println(command);
        Channel channel = null;
        channel = session.openChannel("exec");
        ((ChannelExec) channel).setCommand(command);
        InputStream in = channel.getInputStream();
        channel.connect();
        System.out.println("channel.isConnected()  "+channel.isConnected());
        setInAndOutStream(channel, in);
        channel.disconnect();
        System.out.println("channel.isClosed()  "+channel.isClosed());
    }

    private static void setInAndOutStream(Channel channel, InputStream in) throws IOException, JSchException {
        BufferedReader br = new BufferedReader(new InputStreamReader(in));
        StringBuilder outPutResult = new StringBuilder("");
        int exitStatus = -100;
        String output;
        while (true) {
            while (true) {
                try {
                    String result = br.readLine();
                    if (result == null)
                        break;
                    outPutResult.append(result);
                } catch (Exception ex) {
                    ex.printStackTrace();
                    break;
                }
            }
            output = outPutResult.toString();

            if (channel.isClosed()) {
                exitStatus = channel.getExitStatus();
                break;
            }
        }
        System.out.println(exitStatus);
        System.out.println(output);
    }

    private static void executeCommand(Session session, String command) throws JSchException, IOException{
        connectChannel(session,command);
    }

    /**
     * @param args
     */
    public static void main(String[] args) {
        System.out.println("starting");
        // TODO Auto-generated method stub
        try {
            Session session = connectSession("username", "password", "host");
            if(session!=null) {
                executeCommand(session, "ls");
                executeCommand(session, "cp out.txt copy.txt");

                session.disconnect();
            }
        } catch (JSchException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        System.out.println("done..");
    }

}