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 * https://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 import org.apache.commons.net.util.NetConstants;
26
27 /**
28 * The DiscardUDPClient class is a UDP implementation of a client for the Discard protocol described in RFC 863. To use the class, just open a local UDP port
29 * with {@link org.apache.commons.net.DatagramSocketClient#open open} and call {@link #send send} to send datagrams to the server After you're done sending
30 * discard data, call {@link org.apache.commons.net.DatagramSocketClient#close close()} to clean up properly.
31 *
32 * @see DiscardTCPClient
33 */
34 public class DiscardUDPClient extends DatagramSocketClient {
35
36 /** The default discard port. It is set to 9 according to RFC 863. */
37 public static final int DEFAULT_PORT = 9;
38
39 private final DatagramPacket sendPacket;
40
41 /**
42 * Constructs a new instance.
43 */
44 public DiscardUDPClient() {
45 sendPacket = new DatagramPacket(NetConstants.EMPTY_BTYE_ARRAY, 0);
46 }
47
48 /**
49 * Same as {@code send(data, data.length, host. DiscardUDPClient.DEFAULT_PORT)}.
50 *
51 * @param data the buffer to send
52 * @param host the target host
53 * @see #send(byte[], int, InetAddress, int)
54 * @throws IOException if an error occurs
55 */
56 public void send(final byte[] data, final InetAddress host) throws IOException {
57 send(data, data.length, host, DEFAULT_PORT);
58 }
59
60 /**
61 * Same as {@code send(data, length, host. DiscardUDPClient.DEFAULT_PORT)}.
62 *
63 * @param data the buffer to send
64 * @param length the length of the data in the buffer
65 * @param host the target host
66 * @see #send(byte[], int, InetAddress, int)
67 * @throws IOException if an error occurs
68 */
69 public void send(final byte[] data, final int length, final InetAddress host) throws IOException {
70 send(data, length, host, DEFAULT_PORT);
71 }
72
73 /**
74 * Sends the specified data to the specified server at the specified port.
75 *
76 * @param data The discard data to send.
77 * @param length The length of the data to send. Should be less than or equal to the length of the data byte array.
78 * @param host The address of the server.
79 * @param port The service port.
80 * @throws IOException If an error occurs during the datagram send operation.
81 */
82 public void send(final byte[] data, final int length, final InetAddress host, final int port) throws IOException {
83 sendPacket.setData(data);
84 sendPacket.setLength(length);
85 sendPacket.setAddress(host);
86 sendPacket.setPort(port);
87 checkOpen().send(sendPacket);
88 }
89
90 }