alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

What this is

This file 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.

Other links

The source code

/*
 * Copyright 2001-2004 The Apache Software Foundation
 *
 * Licensed 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;

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

* Usage: chargen [-udp] *

***/ 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] "); System.exit(1); } } }

... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.