001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 018package examples.unix; 019 020import java.io.BufferedReader; 021import java.io.IOException; 022import java.io.InputStreamReader; 023import java.io.InterruptedIOException; 024import java.io.OutputStreamWriter; 025import java.io.PrintWriter; 026import java.net.InetAddress; 027import java.net.SocketException; 028 029import org.apache.commons.net.echo.EchoTCPClient; 030import org.apache.commons.net.echo.EchoUDPClient; 031 032/*** 033 * This is an example program demonstrating how to use the EchoTCPClient 034 * and EchoUDPClient classes. This program connects to the default echo 035 * service port of a specified server, then reads lines from standard 036 * input, writing them to the echo server, and then printing the echo. 037 * The default is to use the TCP port. Use the -udp flag to use the UDP 038 * port. 039 * <p> 040 * Usage: echo [-udp] <hostname> 041 ***/ 042public final class echo 043{ 044 045 public static final void echoTCP(String host) throws IOException 046 { 047 EchoTCPClient client = new EchoTCPClient(); 048 BufferedReader input, echoInput; 049 PrintWriter echoOutput; 050 String line; 051 052 // We want to timeout if a response takes longer than 60 seconds 053 client.setDefaultTimeout(60000); 054 client.connect(host); 055 System.out.println("Connected to " + host + "."); 056 input = new BufferedReader(new InputStreamReader(System.in)); 057 echoOutput = 058 new PrintWriter(new OutputStreamWriter(client.getOutputStream()), true); 059 echoInput = 060 new BufferedReader(new InputStreamReader(client.getInputStream())); 061 062 while ((line = input.readLine()) != null) 063 { 064 echoOutput.println(line); 065 System.out.println(echoInput.readLine()); 066 } 067 068 client.disconnect(); 069 } 070 071 public static final void echoUDP(String host) throws IOException 072 { 073 int length, count; 074 byte[] data; 075 String line; 076 BufferedReader input; 077 InetAddress address; 078 EchoUDPClient client; 079 080 input = new BufferedReader(new InputStreamReader(System.in)); 081 address = InetAddress.getByName(host); 082 client = new EchoUDPClient(); 083 084 client.open(); 085 // If we don't receive an echo within 5 seconds, assume the packet is lost. 086 client.setSoTimeout(5000); 087 System.out.println("Ready to echo to " + host + "."); 088 089 // Remember, there are no guarantees about the ordering of returned 090 // UDP packets, so there is a chance the output may be jumbled. 091 while ((line = input.readLine()) != null) 092 { 093 data = line.getBytes(); 094 client.send(data, address); 095 count = 0; 096 do 097 { 098 try 099 { 100 length = client.receive(data); 101 } 102 // Here we catch both SocketException and InterruptedIOException, 103 // because even though the JDK 1.1 docs claim that 104 // InterruptedIOException is thrown on a timeout, it seems 105 // SocketException is also thrown. 106 catch (SocketException e) 107 { 108 // We timed out and assume the packet is lost. 109 System.err.println( 110 "SocketException: Timed out and dropped packet"); 111 break; 112 } 113 catch (InterruptedIOException e) 114 { 115 // We timed out and assume the packet is lost. 116 System.err.println( 117 "InterruptedIOException: Timed out and dropped packet"); 118 break; 119 } 120 System.out.print(new String(data, 0, length)); 121 count += length; 122 } 123 while (count < data.length); 124 125 System.out.println(); 126 } 127 128 client.close(); 129 } 130 131 132 public static void main(String[] args) 133 { 134 135 if (args.length == 1) 136 { 137 try 138 { 139 echoTCP(args[0]); 140 } 141 catch (IOException e) 142 { 143 e.printStackTrace(); 144 System.exit(1); 145 } 146 } 147 else if (args.length == 2 && args[0].equals("-udp")) 148 { 149 try 150 { 151 echoUDP(args[1]); 152 } 153 catch (IOException e) 154 { 155 e.printStackTrace(); 156 System.exit(1); 157 } 158 } 159 else 160 { 161 System.err.println("Usage: echo [-udp] <hostname>"); 162 System.exit(1); 163 } 164 165 } 166 167} 168