/android-client/lib/commons-net-3.0.1/examples/unix/chargen.java

/*

 * 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.unix;



import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.InterruptedIOException;

import java.net.InetAddress;

import java.net.SocketException;



import org.apache.commons.net.chargen.CharGenTCPClient;

import org.apache.commons.net.chargen.CharGenUDPClient;



/***

 * This is an example program demonstrating how to use the CharGenTCPClient

 * and CharGenUDPClient classes.  This program connects to the default

 * chargen service port of a specified server, then reads 100 lines from

 * of generated output, writing each line to standard output, and then

 * closes the connection.  The UDP invocation of the program sends 50

 * datagrams, printing the reply to each.

 * The default is to use the TCP port.  Use the -udp flag to use the UDP

 * port.

 * <p>

 * Usage: chargen [-udp] <hostname>

 * <p>

 ***/

public final class chargen

{



    public static final void chargenTCP(String host) throws IOException

    {

        int lines = 100;

        String line;

        CharGenTCPClient client = new CharGenTCPClient();

        BufferedReader chargenInput;



        // We want to timeout if a response takes longer than 60 seconds

        client.setDefaultTimeout(60000);

        client.connect(host);

        chargenInput =

            new BufferedReader(new InputStreamReader(client.getInputStream()));



        // We assume the chargen service outputs lines, but it really doesn't

        // have to, so this code might actually not work if no newlines are

        // present.

        while (lines-- > 0)

        {

            if ((line = chargenInput.readLine()) == null)

                break;

            System.out.println(line);

        }



        client.disconnect();

    }



    public static final void chargenUDP(String host) throws IOException

    {

        int packets = 50;

        byte[] data;

        InetAddress address;

        CharGenUDPClient client;



        address = InetAddress.getByName(host);

        client = new CharGenUDPClient();



        client.open();

        // If we don't receive a return packet within 5 seconds, assume

        // the packet is lost.

        client.setSoTimeout(5000);



        while (packets-- > 0)

        {

            client.send(address);



            try

            {

                data = client.receive();

            }

            // Here we catch both SocketException and InterruptedIOException,

            // because even though the JDK 1.1 docs claim that

            // InterruptedIOException is thrown on a timeout, it seems

            // SocketException is also thrown.

            catch (SocketException e)

            {

                // We timed out and assume the packet is lost.

                System.err.println("SocketException: Timed out and dropped packet");

                continue;

            }

            catch (InterruptedIOException e)

            {

                // We timed out and assume the packet is lost.

                System.err.println(

                    "InterruptedIOException: Timed out and dropped packet");

                continue;

            }

            System.out.write(data);

            System.out.flush();

        }



        client.close();

    }





    public static final void main(String[] args)

    {



        if (args.length == 1)

        {

            try

            {

                chargenTCP(args[0]);

            }

            catch (IOException e)

            {

                e.printStackTrace();

                System.exit(1);

            }

        }

        else if (args.length == 2 && args[0].equals("-udp"))

        {

            try

            {

                chargenUDP(args[1]);

            }

            catch (IOException e)

            {

                e.printStackTrace();

                System.exit(1);

            }

        }

        else

        {

            System.err.println("Usage: chargen [-udp] <hostname>");

            System.exit(1);

        }



    }



}