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.discard; 019 020import java.io.IOException; 021import java.net.DatagramPacket; 022import java.net.InetAddress; 023 024import org.apache.commons.net.DatagramSocketClient; 025import org.apache.commons.net.util.NetConstants; 026 027/** 028 * The DiscardUDPClient class is a UDP implementation of a client for the 029 * Discard protocol described in RFC 863. To use the class, 030 * just open a local UDP port 031 * with {@link org.apache.commons.net.DatagramSocketClient#open open } 032 * and call {@link #send send } to send datagrams to the server 033 * After you're done sending discard data, call 034 * {@link org.apache.commons.net.DatagramSocketClient#close close() } 035 * to clean up properly. 036 * 037 * @see DiscardTCPClient 038 */ 039 040public class DiscardUDPClient extends DatagramSocketClient 041{ 042 /** The default discard port. It is set to 9 according to RFC 863. */ 043 public static final int DEFAULT_PORT = 9; 044 045 private final DatagramPacket sendPacket; 046 047 public DiscardUDPClient() 048 { 049 sendPacket = new DatagramPacket(NetConstants.EMPTY_BTYE_ARRAY, 0); 050 } 051 052 053 /** 054 * Sends the specified data to the specified server at the specified port. 055 * 056 * @param data The discard data to send. 057 * @param length The length of the data to send. Should be less than 058 * or equal to the length of the data byte array. 059 * @param host The address of the server. 060 * @param port The service port. 061 * @throws IOException If an error occurs during the datagram send 062 * operation. 063 */ 064 public void send(final byte[] data, final int length, final InetAddress host, final int port) 065 throws IOException 066 { 067 sendPacket.setData(data); 068 sendPacket.setLength(length); 069 sendPacket.setAddress(host); 070 sendPacket.setPort(port); 071 _socket_.send(sendPacket); 072 } 073 074 075 /** 076 * Same as 077 * <code>send(data, length, host. DiscardUDPClient.DEFAULT_PORT)</code>. 078 * @param data the buffer to send 079 * @param length the length of the data in the buffer 080 * @param host the target host 081 * @see #send(byte[], int, InetAddress, int) 082 * @throws IOException if an error occurs 083 */ 084 public void send(final byte[] data, final int length, final InetAddress host) 085 throws IOException 086 { 087 send(data, length, host, DEFAULT_PORT); 088 } 089 090 091 /** 092 * Same as 093 * <code>send(data, data.length, host. DiscardUDPClient.DEFAULT_PORT)</code>. 094 * @param data the buffer to send 095 * @param host the target host 096 * @see #send(byte[], int, InetAddress, int) 097 * @throws IOException if an error occurs 098 */ 099 public void send(final byte[] data, final InetAddress host) throws IOException 100 { 101 send(data, data.length, host, DEFAULT_PORT); 102 } 103 104} 105