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 org.apache.commons.net.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 and EchoUDPClient classes. This program connects to the default echo service port of a 034 * specified server, then reads lines from standard input, writing them to the echo server, and then printing the echo. The default is to use the TCP port. Use 035 * the -udp flag to use the UDP port. 036 * <p> 037 * Usage: echo [-udp] <hostname> 038 */ 039public final class echo { 040 041 public static void echoTCP(final String host) throws IOException { 042 final EchoTCPClient client = new EchoTCPClient(); 043 final BufferedReader input; 044 final BufferedReader echoInput; 045 final PrintWriter echoOutput; 046 String line; 047 048 // We want to timeout if a response takes longer than 60 seconds 049 client.setDefaultTimeout(60000); 050 client.connect(host); 051 System.out.println("Connected to " + host + "."); 052 input = new BufferedReader(new InputStreamReader(System.in)); 053 echoOutput = new PrintWriter(new OutputStreamWriter(client.getOutputStream()), true); 054 echoInput = new BufferedReader(new InputStreamReader(client.getInputStream())); 055 056 while ((line = input.readLine()) != null) { 057 echoOutput.println(line); 058 System.out.println(echoInput.readLine()); 059 } 060 echoOutput.close(); 061 echoInput.close(); 062 echoInput.close(); 063 client.disconnect(); 064 } 065 066 public static void echoUDP(final String host) throws IOException { 067 int length, count; 068 byte[] data; 069 String line; 070 final BufferedReader input; 071 final InetAddress address; 072 final EchoUDPClient client; 073 074 input = new BufferedReader(new InputStreamReader(System.in)); 075 address = InetAddress.getByName(host); 076 client = new EchoUDPClient(); 077 078 client.open(); 079 // If we don't receive an echo within 5 seconds, assume the packet is lost. 080 client.setSoTimeout(5000); 081 System.out.println("Ready to echo to " + host + "."); 082 083 // Remember, there are no guarantees about the ordering of returned 084 // UDP packets, so there is a chance the output may be jumbled. 085 while ((line = input.readLine()) != null) { 086 data = line.getBytes(); 087 client.send(data, address); 088 count = 0; 089 do { 090 try { 091 length = client.receive(data); 092 } 093 // Here we catch both SocketException and InterruptedIOException, 094 // because even though the JDK 1.1 docs claim that 095 // InterruptedIOException is thrown on a timeout, it seems 096 // SocketException is also thrown. 097 catch (final SocketException e) { 098 // We timed out and assume the packet is lost. 099 System.err.println("SocketException: Timed out and dropped packet"); 100 break; 101 } catch (final InterruptedIOException e) { 102 // We timed out and assume the packet is lost. 103 System.err.println("InterruptedIOException: Timed out and dropped packet"); 104 break; 105 } 106 System.out.print(new String(data, 0, length)); 107 count += length; 108 } while (count < data.length); 109 110 System.out.println(); 111 } 112 113 client.close(); 114 } 115 116 public static void main(final String[] args) { 117 118 if (args.length == 1) { 119 try { 120 echoTCP(args[0]); 121 } catch (final IOException e) { 122 e.printStackTrace(); 123 System.exit(1); 124 } 125 } else if (args.length == 2 && args[0].equals("-udp")) { 126 try { 127 echoUDP(args[1]); 128 } catch (final IOException e) { 129 e.printStackTrace(); 130 System.exit(1); 131 } 132 } else { 133 System.err.println("Usage: echo [-udp] <hostname>"); 134 System.exit(1); 135 } 136 137 } 138 139}