java 实现telnet服务器执行脚本

import java.io.InputStream;
import java.io.PrintStream;

import org.apache.commons.net.telnet.TelnetClient;

public class TelnetTest
{
    private TelnetClient telnet = new TelnetClient();
   
    private InputStream in;
   
    private PrintStream out;
   
    private char prompt = '$';
   
    public TelnetTest(String server, String user, String password)
    {
        try
        {
            // Connect to the specified server
            telnet.connect(server, 23);
           
            // Get input and output stream references
            in = telnet.getInputStream();
            out = new PrintStream(telnet.getOutputStream());
            // Log the user on
            readUntil("login: ");
            write(user);
            readUntil("Password: ");
            write(password);

            // Advance to a prompt
            readUntil(prompt + " ");
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
    }
   
    public void su(String password)
    {
        try
        {
            write("su");
            readUntil("Password: ");
            write(password);
            prompt = '#';
            readUntil(prompt + " ");
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
    }
   
    public String readUntil(String pattern)
    {
        try
        {
            char lastChar = pattern.charAt(pattern.length() - 1);