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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  
18  package org.apache.commons.net.discard;
19  
20  import java.io.IOException;
21  import java.net.DatagramPacket;
22  import java.net.InetAddress;
23  
24  import org.apache.commons.net.DatagramSocketClient;
25  
26  /***
27   * The DiscardUDPClient class is a UDP implementation of a client for the
28   * Discard protocol described in RFC 863.  To use the class,
29   * just open a local UDP port
30   * with {@link org.apache.commons.net.DatagramSocketClient#open  open }
31   * and call {@link #send  send } to send datagrams to the server
32   * After you're done sending discard data, call
33   * {@link org.apache.commons.net.DatagramSocketClient#close  close() }
34   * to clean up properly.
35   * <p>
36   * <p>
37   * @author Daniel F. Savarese
38   * @see DiscardTCPClient
39   ***/
40  
41  public class DiscardUDPClient extends DatagramSocketClient
42  {
43      /*** The default discard port.  It is set to 9 according to RFC 863. ***/
44      public static final int DEFAULT_PORT = 9;
45  
46      DatagramPacket _sendPacket;
47  
48      public DiscardUDPClient()
49      {
50          _sendPacket = new DatagramPacket(new byte[0], 0);
51      }
52  
53  
54      /***
55       * Sends the specified data to the specified server at the specified port.
56       * <p>
57       * @param data  The discard data to send.
58       * @param length  The length of the data to send.  Should be less than
59       *    or equal to the length of the data byte array.
60       * @param host  The address of the server.
61       * @param port  The service port.
62       * @exception IOException If an error occurs during the datagram send
63       *            operation.
64       ***/
65      public void send(byte[] data, int length, InetAddress host, int port)
66      throws IOException
67      {
68          _sendPacket.setData(data);
69          _sendPacket.setLength(length);
70          _sendPacket.setAddress(host);
71          _sendPacket.setPort(port);
72          _socket_.send(_sendPacket);
73      }
74  
75  
76      /***
77       * Same as
78       * <code>send(data, length, host. DiscardUDPClient.DEFAULT_PORT)</code>.
79       ***/
80      public void send(byte[] data, int length, InetAddress host)
81      throws IOException
82      {
83          send(data, length, host, DEFAULT_PORT);
84      }
85  
86  
87      /***
88       * Same as
89       * <code>send(data, data.length, host. DiscardUDPClient.DEFAULT_PORT)</code>.
90       ***/
91      public void send(byte[] data, InetAddress host) throws IOException
92      {
93          send(data, data.length, host, DEFAULT_PORT);
94      }
95  
96  }
97