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;
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 * <p>
042 ***/
043public 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