Commons Net example source code file (TelnetClientExample.java)

This example Commons Net source code file (TelnetClientExample.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Commons Net tags/keywords

exception, exception, fileoutputstream, invalidtelnetoptionexception, io, ioexception, ioexception, simpleoptionhandler, string, string, stringtokenizer, stringtokenizer, telnetclient, telnetclientexample, terminaltypeoptionhandler, util

The Commons Net TelnetClientExample.java source code

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package examples.telnet;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.FileOutputStream;
import java.util.StringTokenizer;

import org.apache.commons.net.telnet.TelnetClient;
import org.apache.commons.net.telnet.TelnetNotificationHandler;
import org.apache.commons.net.telnet.SimpleOptionHandler;
import org.apache.commons.net.telnet.EchoOptionHandler;
import org.apache.commons.net.telnet.TerminalTypeOptionHandler;
import org.apache.commons.net.telnet.SuppressGAOptionHandler;
import org.apache.commons.net.telnet.InvalidTelnetOptionException;


/***
 * This is a simple example of use of TelnetClient.
 * An external option handler (SimpleTelnetOptionHandler) is used.
 * Initial configuration requested by TelnetClient will be:
 * WILL ECHO, WILL SUPPRESS-GA, DO SUPPRESS-GA.
 * VT100 terminal type will be subnegotiated.
 * <p>
 * Also, use of the sendAYT(), getLocalOptionState(), getRemoteOptionState()
 * is demonstrated.
 * When connected, type AYT to send an AYT command to the server and see
 * the result.
 * Type OPT to see a report of the state of the first 25 options.
 * <p>
 * @author Bruno D'Avanzo
 ***/
public class TelnetClientExample implements Runnable, TelnetNotificationHandler
{
    static TelnetClient tc = null;

    /***
     * Main for the TelnetClientExample.
     ***/
    public static void main(String[] args) throws Exception
    {
        FileOutputStream fout = null;

        if(args.length < 1)
        {
            System.err.println("Usage: TelnetClientExample1 <remote-ip> []");
            System.exit(1);
        }

        String remoteip = args[0];

        int remoteport;

        if (args.length > 1)
        {
            remoteport = (new Integer(args[1])).intValue();
        }
        else
        {
            remoteport = 23;
        }

        try
        {
            fout = new FileOutputStream ("spy.log", true);
        }
        catch (IOException e)
        {
            System.err.println(
                "Exception while opening the spy file: "
                + e.getMessage());
        }

        tc = new TelnetClient();

        TerminalTypeOptionHandler ttopt = new TerminalTypeOptionHandler("VT100", false, false, true, false);
        EchoOptionHandler echoopt = new EchoOptionHandler(true, false, true, false);
        SuppressGAOptionHandler gaopt = new SuppressGAOptionHandler(true, true, true, true);

        try
        {
            tc.addOptionHandler(ttopt);
            tc.addOptionHandler(echoopt);
            tc.addOptionHandler(gaopt);
        }
        catch (InvalidTelnetOptionException e)
        {
            System.err.println("Error registering option handlers: " + e.getMessage());
        }

        while (true)
        {
            boolean end_loop = false;
            try
            {
                tc.connect(remoteip, remoteport);


                Thread reader = new Thread (new TelnetClientExample());
                tc.registerNotifHandler(new TelnetClientExample());
                System.out.println("TelnetClientExample");
                System.out.println("Type AYT to send an AYT telnet command");
                System.out.println("Type OPT to print a report of status of options (0-24)");
                System.out.println("Type REGISTER to register a new SimpleOptionHandler");
                System.out.println("Type UNREGISTER to unregister an OptionHandler");
                System.out.println("Type SPY to register the spy (connect to port 3333 to spy)");
                System.out.println("Type UNSPY to stop spying the connection");

                reader.start();
                OutputStream outstr = tc.getOutputStream();

                byte[] buff = new byte[1024];
                int ret_read = 0;

                do
                {
                    try
                    {
                        ret_read = System.in.read(buff);
                        if(ret_read > 0)
                        {
                            if((new String(buff, 0, ret_read)).startsWith("AYT"))
                            {
                                try
                                {
                                    System.out.println("Sending AYT");

                                    System.out.println("AYT response:" + tc.sendAYT(5000));
                                }
                                catch (IOException e)
                                {
                                    System.err.println("Exception waiting AYT response: " + e.getMessage());
                                }
                            }
                            else if((new String(buff, 0, ret_read)).startsWith("OPT"))
                            {
                                 System.out.println("Status of options:");
                                 for(int ii=0; ii<25; ii++)
                                    System.out.println("Local Option " + ii + ":" + tc.getLocalOptionState(ii) + " Remote Option " + ii + ":" + tc.getRemoteOptionState(ii));
                            }
                            else if((new String(buff, 0, ret_read)).startsWith("REGISTER"))
                            {
                                StringTokenizer st = new StringTokenizer(new String(buff));
                                try
                                {
                                    st.nextToken();
                                    int opcode = Integer.parseInt(st.nextToken());
                                    boolean initlocal = Boolean.parseBoolean(st.nextToken());
                                    boolean initremote = Boolean.parseBoolean(st.nextToken());
                                    boolean acceptlocal = Boolean.parseBoolean(st.nextToken());
                                    boolean acceptremote = Boolean.parseBoolean(st.nextToken());
                                    SimpleOptionHandler opthand = new SimpleOptionHandler(opcode, initlocal, initremote,
                                                                    acceptlocal, acceptremote);
                                    tc.addOptionHandler(opthand);
                                }
                                catch (Exception e)
                                {
                                    if(e instanceof InvalidTelnetOptionException)
                                    {
                                        System.err.println("Error registering option: " + e.getMessage());
                                    }
                                    else
                                    {
                                        System.err.println("Invalid REGISTER command.");
                                        System.err.println("Use REGISTER optcode initlocal initremote acceptlocal acceptremote");
                                        System.err.println("(optcode is an integer.)");
                                        System.err.println("(initlocal, initremote, acceptlocal, acceptremote are boolean)");
                                    }
                                }
                            }
                            else if((new String(buff, 0, ret_read)).startsWith("UNREGISTER"))
                            {
                                StringTokenizer st = new StringTokenizer(new String(buff));
                                try
                                {
                                    st.nextToken();
                                    int opcode = (new Integer(st.nextToken())).intValue();
                                    tc.deleteOptionHandler(opcode);
                                }
                                catch (Exception e)
                                {
                                    if(e instanceof InvalidTelnetOptionException)
                                    {
                                        System.err.println("Error unregistering option: " + e.getMessage());
                                    }
                                    else
                                    {
                                        System.err.println("Invalid UNREGISTER command.");
                                        System.err.println("Use UNREGISTER optcode");
                                        System.err.println("(optcode is an integer)");
                                    }
                                }
                            }
                            else if((new String(buff, 0, ret_read)).startsWith("SPY"))
                            {
                                tc.registerSpyStream(fout);
                            }
                            else if((new String(buff, 0, ret_read)).startsWith("UNSPY"))
                            {
                                tc.stopSpyStream();
                            }
                            else
                            {
                                try
                                {
                                        outstr.write(buff, 0 , ret_read);
                                        outstr.flush();
                                }
                                catch (IOException e)
                                {
                                        end_loop = true;
                                }
                            }
                        }
                    }
                    catch (IOException e)
                    {
                        System.err.println("Exception while reading keyboard:" + e.getMessage());
                        end_loop = true;
                    }
                }
                while((ret_read > 0) && (end_loop == false));

                try
                {
                    tc.disconnect();
                }
                catch (IOException e)
                {
                          System.err.println("Exception while connecting:" + e.getMessage());
                }
            }
            catch (IOException e)
            {
                    System.err.println("Exception while connecting:" + e.getMessage());
                    System.exit(1);
            }
        }
    }


    /***
     * Callback method called when TelnetClient receives an option
     * negotiation command.
     * <p>
     * @param negotiation_code - type of negotiation command received
     * (RECEIVED_DO, RECEIVED_DONT, RECEIVED_WILL, RECEIVED_WONT)
     * <p>
     * @param option_code - code of the option negotiated
     * <p>
     ***/
    public void receivedNegotiation(int negotiation_code, int option_code)
    {
        String command = null;
        if(negotiation_code == TelnetNotificationHandler.RECEIVED_DO)
        {
            command = "DO";
        }
        else if(negotiation_code == TelnetNotificationHandler.RECEIVED_DONT)
        {
            command = "DONT";
        }
        else if(negotiation_code == TelnetNotificationHandler.RECEIVED_WILL)
        {
            command = "WILL";
        }
        else if(negotiation_code == TelnetNotificationHandler.RECEIVED_WONT)
        {
            command = "WONT";
        }
        System.out.println("Received " + command + " for option code " + option_code);
   }

    /***
     * Reader thread.
     * Reads lines from the TelnetClient and echoes them
     * on the screen.
     ***/
    public void run()
    {
        InputStream instr = tc.getInputStream();

        try
        {
            byte[] buff = new byte[1024];
            int ret_read = 0;

            do
            {
                ret_read = instr.read(buff);
                if(ret_read > 0)
                {
                    System.out.print(new String(buff, 0, ret_read));
                }
            }
            while (ret_read >= 0);
        }
        catch (IOException e)
        {
            System.err.println("Exception while reading socket:" + e.getMessage());
        }

        try
        {
            tc.disconnect();
        }
        catch (IOException e)
        {
            System.err.println("Exception while closing telnet:" + e.getMessage());
        }
    }
}