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1 package examples; 2 3 /* ==================================================================== 4 * The Apache Software License, Version 1.1 5 * 6 * Copyright (c) 2001 The Apache Software Foundation. All rights 7 * reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in 18 * the documentation and/or other materials provided with the 19 * distribution. 20 * 21 * 3. The end-user documentation included with the redistribution, 22 * if any, must include the following acknowledgment: 23 * "This product includes software developed by the 24 * Apache Software Foundation (http://www.apache.org/)." 25 * Alternately, this acknowledgment may appear in the software itself, 26 * if and wherever such third-party acknowledgments normally appear. 27 * 28 * 4. The names "Apache" and "Apache Software Foundation" and 29 * "Apache Commons" must not be used to endorse or promote products 30 * derived from this software without prior written permission. For 31 * written permission, please contact apache@apache.org. 32 * 33 * 5. Products derived from this software may not be called "Apache", 34 * nor may "Apache" appear in their name, without 35 * prior written permission of the Apache Software Foundation. 36 * 37 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED 38 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 39 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 40 * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR 41 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 42 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 43 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 44 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 45 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 46 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 47 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 48 * SUCH DAMAGE. 49 * ==================================================================== 50 * 51 * This software consists of voluntary contributions made by many 52 * individuals on behalf of the Apache Software Foundation. For more 53 * information on the Apache Software Foundation, please see 54 * <http://www.apache.org/>;. 55 */ 56 57 import java.io.BufferedReader; 58 import java.io.IOException; 59 import java.io.InputStreamReader; 60 import java.io.InterruptedIOException; 61 import java.net.InetAddress; 62 import java.net.SocketException; 63 import org.apache.commons.net.CharGenTCPClient; 64 import org.apache.commons.net.CharGenUDPClient; 65 66 /**** 67 * This is an example program demonstrating how to use the CharGenTCPClient 68 * and CharGenUDPClient classes. This program connects to the default 69 * chargen service port of a specified server, then reads 100 lines from 70 * of generated output, writing each line to standard output, and then 71 * closes the connection. The UDP invocation of the program sends 50 72 * datagrams, printing the reply to each. 73 * The default is to use the TCP port. Use the -udp flag to use the UDP 74 * port. 75 * <p> 76 * Usage: chargen [-udp] <hostname> 77 * <p> 78 ***/ 79 public final class chargen 80 { 81 82 public static final void chargenTCP(String host) throws IOException 83 { 84 int lines = 100; 85 String line; 86 CharGenTCPClient client = new CharGenTCPClient(); 87 BufferedReader chargenInput; 88 89 // We want to timeout if a response takes longer than 60 seconds 90 client.setDefaultTimeout(60000); 91 client.connect(host); 92 chargenInput = 93 new BufferedReader(new InputStreamReader(client.getInputStream())); 94 95 // We assume the chargen service outputs lines, but it really doesn't 96 // have to, so this code might actually not work if no newlines are 97 // present. 98 while (lines-- > 0) 99 { 100 if ((line = chargenInput.readLine()) == null) 101 break; 102 System.out.println(line); 103 } 104 105 client.disconnect(); 106 } 107 108 public static final void chargenUDP(String host) throws IOException 109 { 110 int packets = 50; 111 byte[] data; 112 InetAddress address; 113 CharGenUDPClient client; 114 115 address = InetAddress.getByName(host); 116 client = new CharGenUDPClient(); 117 118 client.open(); 119 // If we don't receive a return packet within 5 seconds, assume 120 // the packet is lost. 121 client.setSoTimeout(5000); 122 123 while (packets-- > 0) 124 { 125 client.send(address); 126 127 try 128 { 129 data = client.receive(); 130 } 131 // Here we catch both SocketException and InterruptedIOException, 132 // because even though the JDK 1.1 docs claim that 133 // InterruptedIOException is thrown on a timeout, it seems 134 // SocketException is also thrown. 135 catch (SocketException e) 136 { 137 // We timed out and assume the packet is lost. 138 System.err.println("SocketException: Timed out and dropped packet"); 139 continue; 140 } 141 catch (InterruptedIOException e) 142 { 143 // We timed out and assume the packet is lost. 144 System.err.println( 145 "InterruptedIOException: Timed out and dropped packet"); 146 continue; 147 } 148 System.out.write(data); 149 System.out.flush(); 150 } 151 152 client.close(); 153 } 154 155 156 public static final void main(String[] args) 157 { 158 159 if (args.length == 1) 160 { 161 try 162 { 163 chargenTCP(args[0]); 164 } 165 catch (IOException e) 166 { 167 e.printStackTrace(); 168 System.exit(1); 169 } 170 } 171 else if (args.length == 2 && args[0].equals("-udp")) 172 { 173 try 174 { 175 chargenUDP(args[1]); 176 } 177 catch (IOException e) 178 { 179 e.printStackTrace(); 180 System.exit(1); 181 } 182 } 183 else 184 { 185 System.err.println("Usage: chargen [-udp] <hostname>"); 186 System.exit(1); 187 } 188 189 } 190 191 } 192

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