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
018 package examples;
019
020 import java.io.BufferedReader;
021 import java.io.IOException;
022 import java.io.InputStreamReader;
023 import java.io.InterruptedIOException;
024 import java.io.OutputStreamWriter;
025 import java.io.PrintWriter;
026 import java.net.InetAddress;
027 import java.net.SocketException;
028
029 import org.apache.commons.net.echo.EchoTCPClient;
030 import 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 * <p>
042 ***/
043 public final class echo
044 {
045
046 public static final void echoTCP(String host) throws IOException
047 {
048 EchoTCPClient client = new EchoTCPClient();
049 BufferedReader input, echoInput;
050 PrintWriter echoOutput;
051 String line;
052
053 // We want to timeout if a response takes longer than 60 seconds
054 client.setDefaultTimeout(60000);
055 client.connect(host);
056 System.out.println("Connected to " + host + ".");
057 input = new BufferedReader(new InputStreamReader(System.in));
058 echoOutput =
059 new PrintWriter(new OutputStreamWriter(client.getOutputStream()), true);
060 echoInput =
061 new BufferedReader(new InputStreamReader(client.getInputStream()));
062
063 while ((line = input.readLine()) != null)
064 {
065 echoOutput.println(line);
066 System.out.println(echoInput.readLine());
067 }
068
069 client.disconnect();
070 }
071
072 public static final void echoUDP(String host) throws IOException
073 {
074 int length, count;
075 byte[] data;
076 String line;
077 BufferedReader input;
078 InetAddress address;
079 EchoUDPClient client;
080
081 input = new BufferedReader(new InputStreamReader(System.in));
082 address = InetAddress.getByName(host);
083 client = new EchoUDPClient();
084
085 client.open();
086 // If we don't receive an echo within 5 seconds, assume the packet is lost.
087 client.setSoTimeout(5000);
088 System.out.println("Ready to echo to " + host + ".");
089
090 // Remember, there are no guarantees about the ordering of returned
091 // UDP packets, so there is a chance the output may be jumbled.
092 while ((line = input.readLine()) != null)
093 {
094 data = line.getBytes();
095 client.send(data, address);
096 count = 0;
097 do
098 {
099 try
100 {
101 length = client.receive(data);
102 }
103 // Here we catch both SocketException and InterruptedIOException,
104 // because even though the JDK 1.1 docs claim that
105 // InterruptedIOException is thrown on a timeout, it seems
106 // SocketException is also thrown.
107 catch (SocketException e)
108 {
109 // We timed out and assume the packet is lost.
110 System.err.println(
111 "SocketException: Timed out and dropped packet");
112 break;
113 }
114 catch (InterruptedIOException e)
115 {
116 // We timed out and assume the packet is lost.
117 System.err.println(
118 "InterruptedIOException: Timed out and dropped packet");
119 break;
120 }
121 System.out.print(new String(data, 0, length));
122 count += length;
123 }
124 while (count < data.length);
125
126 System.out.println();
127 }
128
129 client.close();
130 }
131
132
133 public static final void main(String[] args)
134 {
135
136 if (args.length == 1)
137 {
138 try
139 {
140 echoTCP(args[0]);
141 }
142 catch (IOException e)
143 {
144 e.printStackTrace();
145 System.exit(1);
146 }
147 }
148 else if (args.length == 2 && args[0].equals("-udp"))
149 {
150 try
151 {
152 echoUDP(args[1]);
153 }
154 catch (IOException e)
155 {
156 e.printStackTrace();
157 System.exit(1);
158 }
159 }
160 else
161 {
162 System.err.println("Usage: echo [-udp] <hostname>");
163 System.exit(1);
164 }
165
166 }
167
168 }
169