TelnetTransport.java

package org.opennaas.extensions.transports.telnet;

import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;

import org.apache.commons.net.telnet.EchoOptionHandler;
import org.apache.commons.net.telnet.SuppressGAOptionHandler;
import org.apache.commons.net.telnet.TelnetClient;
import org.apache.commons.net.telnet.TerminalTypeOptionHandler;
import org.opennaas.core.resources.transport.IStreamTransport;
import org.opennaas.core.resources.transport.TransportException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * This class implements a Telnet transport client. It can connect to telnet enabled remote devices and send/receive characters/bytes using the telnet
 * protocol
 * 
 * @author edu
 * 
 */
public class TelnetTransport implements IStreamTransport {

	public static final String	TELNET			= "telnet";

	/** TelnetTransport Logger */
	static private Logger		logger			= LoggerFactory.getLogger(TelnetTransport.class);

	/** The telnet client library **/
	private TelnetClient		telnetClient	= null;

	/** PrintWriter to write to the socket */
	private PrintWriter			outPrint;

	/** The host to connect */
	private String				host			= null;

	/** The port to connect */
	private String				port			= null;

	/** The read time out **/
	private static final int	READ_TIMEOUT	= 300000;

	public TelnetTransport(String host, String port) {
		this.host = host;
		this.port = port;
	}

	public TelnetTransport(String host) {
		this.host = host;
		this.port = "23";
	}

	public void connect() throws TransportException {
		logger.info("Telnet Transport trying to connect...");

		// Create a new telnet client
		telnetClient = new TelnetClient();

		// VT100 terminal type will be subnegotiated
		TerminalTypeOptionHandler ttopt = new TerminalTypeOptionHandler("VT100", false, false, true, false);
		// WILL SUPPRESS-GA, DO SUPPRESS-GA options
		SuppressGAOptionHandler gaopt = new SuppressGAOptionHandler(true, true, true, true);
		// WON'T ECHO, DON'T ECHO
		EchoOptionHandler echoopt = new EchoOptionHandler();

		try {
			// set telnet client options
			telnetClient.addOptionHandler(ttopt);
			telnetClient.addOptionHandler(gaopt);
			telnetClient.addOptionHandler(echoopt);

			// connect
			telnetClient.connect(host, Integer.parseInt(port));

			// set the read timeout
			telnetClient.setSoTimeout(READ_TIMEOUT);

			// Initialize the print writer
			outPrint = new PrintWriter(telnetClient.getOutputStream(), true);
		} catch (Exception e) {
			e.printStackTrace();
			throw new TransportException("Could not connect, unable to open telnet session " + e.getMessage());
		}
	}

	public void disconnect() throws TransportException {
		try {
			telnetClient.disconnect();
		} catch (Exception e) {
			e.printStackTrace();
			throw new TransportException("Problems when disconnecting: " + e.getMessage());
		}
	}

	public void send(byte[] rawInput) throws TransportException {
		try {
			logger.debug("Message to be sent: " + rawInput);
			outPrint.println(rawInput);
		} catch (Exception e) {
			e.printStackTrace();
			throw new TransportException("Problems when sending message: " + e.getMessage());
		}
	}

	public void send(char[] rawInput) throws TransportException {
		try {
			logger.debug("Message to be sent: " + rawInput.toString());
			outPrint.println(rawInput);
		} catch (Exception e) {
			e.printStackTrace();
			throw new TransportException("Problems when sending message: " + e.getMessage());
		}
	}

	public InputStream getInputStream() throws TransportException {
		return telnetClient.getInputStream();
	}

	public OutputStream getOutputStream() throws TransportException {
		return telnetClient.getOutputStream();
	}
}