SSH, InputStream e OutputStream

package ssh2;

import com.jcraft.jsch.*;
import javax.swing.JOptionPane;

public class Shell {

    public static void main(String[] arg) {

        try {
            JSch jsch = new JSch();

            //jsch.setKnownHosts("/home/foo/.ssh/known_hosts");

            String host = null;
            if (arg.length > 0) {
                host = arg[0];
            } else {
                host = JOptionPane.showInputDialog("Enter username@hostname",
                        System.getProperty("user.name")
                        + "@localhost");
            }
            String user = host.substring(0, host.indexOf('@'));
            host = host.substring(host.indexOf('@') + 1);

            Session session = jsch.getSession(user, host, 22);

            String passwd = JOptionPane.showInputDialog("Enter password");
            session.setPassword(passwd);

            UserInfo ui = new MyUserInfo() {

                @Override
                public void showMessage(String message) {
                    JOptionPane.showMessageDialog(null, message);
                }

                @Override
                public boolean promptYesNo(String message) {
                    Object[] options = {"yes", "no"};
                    int foo = JOptionPane.showOptionDialog(null,
                            message,
                            "Warning",
                            JOptionPane.DEFAULT_OPTION,
                            JOptionPane.WARNING_MESSAGE,
                            null, options, options[0]);
                    return foo == 0;
                }
                // If password is not given before the invocation of Session#connect(),
                // implement also following methods,
                // * UserInfo#getPassword(),
                // * UserInfo#promptPassword(String message) and
                // * UIKeyboardInteractive#promptKeyboardInteractive()
            };

            session.setUserInfo(ui);

            // It must not be recommended, but if you want to skip host-key check,
            // invoke following,
            // session.setConfig("StrictHostKeyChecking", "no");

            //session.connect();
            session.connect(30000); // making a connection with timeout.

            Channel channel = session.openChannel("shell");

            // Enable agent-forwarding.
            //((ChannelShell)channel).setAgentForwarding(true);

            channel.setInputStream(System.in);
            /*
             * // a hack for MS-DOS prompt on Windows.
             * channel.setInputStream(new FilterInputStream(System.in){ public
             * int read(byte[] b, int off, int len)throws IOException{ return
             * in.read(b, off, (len>1024?1024:len)); } });
             */

            channel.setOutputStream(System.out);

            /*
             * // Choose the pty-type "vt102".
             * ((ChannelShell)channel).setPtyType("vt102");
             */

            /*
             * // Set environment variable "LANG" as "ja_JP.eucJP".
             * ((ChannelShell)channel).setEnv("LANG", "ja_JP.eucJP");
             */

            //channel.connect();
            channel.connect(3 * 1000);
        } catch (Exception e) {
            System.out.println(e);
        }
    }

    public static abstract class MyUserInfo
            implements UserInfo, UIKeyboardInteractive {

        @Override
        public String getPassword() {
            return null;
        }

        @Override
        public boolean promptYesNo(String str) {
            return false;
        }

        @Override
        public String getPassphrase() {
            return null;
        }

        @Override
        public boolean promptPassphrase(String message) {
            return false;
        }

        @Override
        public boolean promptPassword(String message) {
            return false;
        }

        @Override
        public void showMessage(String message) {
        }

        @Override
        public String[] promptKeyboardInteractive(String destination,
                String name,
                String instruction,
                String[] prompt,
                boolean[] echo) {
            return null;
        }
    }
}