TelnetWrapper.java

/*
 * This file is part of "JTA - Telnet/SSH for the JAVA(tm) platform".
 *
 * (c) Matthias L. Jugel, Marcus Meißner 1996-2005. All Rights Reserved.
 *
 * Please visit http://javatelnet.org/ for updates and contact.
 *
 * --LICENSE NOTICE--
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 * --LICENSE NOTICE--
 *
 */

package de.mud.telnet;

import java.io.IOException;

import de.mud.jta.Wrapper;

/**
 * The telnet wrapper is a sample class for how to use the telnet protocol
 * handler of the JTA source package. To write a program using the wrapper you
 * may use the following piece of code as an example:
 * 
 * <PRE>
 * TelnetWrapper telnet = new TelnetWrapper();
 * try {
 * 	telnet.connect(args[0], 23);
 * 	telnet.login("user", "password");
 * 	telnet.setPrompt("user@host");
 * 	telnet.waitfor("Terminal type?");
 * 	telnet.send("dumb");
 * 	System.out.println(telnet.send("ls -l"));
 * } catch (java.io.IOException e) {
 * 	e.printStackTrace();
 * }
 * </PRE>
 * 
 * Please keep in mind that the password is visible for anyone who can download
 * the class file. So use this only for public accounts or if you are absolutely
 * sure nobody can see the file.
 * <P>
 * <B>Maintainer:</B> Matthias L. Jugel
 * 
 * @version $Id: TelnetWrapper.java 499 2005-09-29 08:24:54Z leo $
 * @author Matthias L. Jugel, Marcus Mei�ner
 */
public class TelnetWrapper extends Wrapper {
	protected TelnetProtocolHandler handler;

	/** debugging level */
	private final static int debug = 0;

	public TelnetWrapper() {
		handler = new TelnetProtocolHandler() {
			/** get the current terminal type */
			public String getTerminalType() {
				return "vt320";
			}

			/** get the current window size */
			public Dimension getWindowSize() {
				return new Dimension(80, 25);
			}

			/** notify about local echo */
			public void setLocalEcho(boolean echo) {
				/* EMPTY */
			}

			/** write data to our back end */
			public void write(byte[] b) throws IOException {
				out.write(b);
			}

			/** sent on IAC EOR (prompt terminator for remote access systems). */
			public void notifyEndOfRecord() {
			}
		};
	}

	public TelnetProtocolHandler getHandler() {
		return handler;
	}

	public void connect(String host, int port) throws IOException {
		super.connect(host, port);
		handler.reset();
	}

	/**
	 * Send a command to the remote host. A newline is appended and if a prompt
	 * is set it will return the resulting data until the prompt is encountered.
	 * 
	 * @param cmd
	 *            the command
	 * @return output of the command or null if no prompt is set
	 */
	public String send(String cmd) throws IOException {
		byte arr[];
		arr = (cmd).getBytes();
		return send(arr);
	}

	public String send(byte[] arr) throws IOException {
		handler.transpose(arr);
		if (getPrompt() != null)
			return waitfor(getPrompt());
		return null;
	}

	/**
	 * Read data from the socket and use telnet negotiation before returning the
	 * data read.
	 * 
	 * @param b
	 *            the input buffer to read in
	 * @return the amount of bytes read
	 */
	public int read(byte[] b) throws IOException {
		/* process all already read bytes */
		int n;

		do {
			n = handler.negotiate(b);
			if (n > 0)
				return n;
		} while (n == 0);

		while (n <= 0) {
			do {
				n = handler.negotiate(b);
				if (n > 0)
					return n;
			} while (n == 0);
			n = in.read(b);
			if (n < 0)
				return n;
			handler.inputfeed(b, n);
			n = handler.negotiate(b);
		}
		return n;
	}

	public void write(char c) throws IOException {
		out.write(c);
	}

	public void write(int i) throws IOException {
		out.write(i);

	}

	public void flush() throws IOException {
		out.flush();
	}
}