1 /* 2 * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package java.net; 27 28 /** 29 * This class represents a Network Interface address. In short it's an 30 * IP address, a subnet mask and a broadcast address when the address is 31 * an IPv4 one. An IP address and a network prefix length in the case 32 * of IPv6 address. 33 * 34 * @see java.net.NetworkInterface 35 * @since 1.6 36 */ 37 public class InterfaceAddress { 38 private InetAddress address = null; 39 private Inet4Address broadcast = null; 40 private short maskLength = 0; 41 42 /* 43 * Package private constructor. Can't be built directly, instances are 44 * obtained through the NetworkInterface class. 45 */ 46 InterfaceAddress() { 47 } 48 49 InterfaceAddress(InetAddress address, Inet4Address broadcast, InetAddress netmask) { 50 this.address = address; 51 this.broadcast = broadcast; 52 this.maskLength = countPrefixLength(netmask); 53 } 54 55 /** 56 * Counts the prefix length for the netmask address. 57 * 58 * A valid netmask address must start with a continuous sequence of 1, followed by a continuous 59 * sequence of 0. 60 */ 61 private short countPrefixLength(InetAddress netmask) { 62 short count = 0; 63 for (byte b : netmask.getAddress()) { 64 for (; b != 0; b <<= 1, ++count); 65 } 66 return count; 67 } 68 69 /** 70 * Returns an {@code InetAddress} for this address. 71 * 72 * @return the {@code InetAddress} for this address. 73 */ 74 public InetAddress getAddress() { 75 return address; 76 } 77 78 /** 79 * Returns an {@code InetAddress} for the broadcast address 80 * for this InterfaceAddress. 81 * <p> 82 * Only IPv4 networks have broadcast address therefore, in the case 83 * of an IPv6 network, {@code null} will be returned. 84 * 85 * @return the {@code InetAddress} representing the broadcast 86 * address or {@code null} if there is no broadcast address. 87 */ 88 public InetAddress getBroadcast() { 89 return broadcast; 90 } 91 92 /** 93 * Returns the network prefix length for this address. This is also known 94 * as the subnet mask in the context of IPv4 addresses. 95 * Typical IPv4 values would be 8 (255.0.0.0), 16 (255.255.0.0) 96 * or 24 (255.255.255.0). <p> 97 * Typical IPv6 values would be 128 (::1/128) or 10 (fe80::203:baff:fe27:1243/10) 98 * 99 * @return a {@code short} representing the prefix length for the 100 * subnet of that address. 101 */ 102 public short getNetworkPrefixLength() { 103 return maskLength; 104 } 105 106 /** 107 * Compares this object against the specified object. 108 * The result is {@code true} if and only if the argument is 109 * not {@code null} and it represents the same interface address as 110 * this object. 111 * <p> 112 * Two instances of {@code InterfaceAddress} represent the same 113 * address if the InetAddress, the prefix length and the broadcast are 114 * the same for both. 115 * 116 * @param obj the object to compare against. 117 * @return {@code true} if the objects are the same; 118 * {@code false} otherwise. 119 * @see java.net.InterfaceAddress#hashCode() 120 */ 121 public boolean equals(Object obj) { 122 if (!(obj instanceof InterfaceAddress)) { 123 return false; 124 } 125 InterfaceAddress cmp = (InterfaceAddress) obj; 126 if ( !(address == null ? cmp.address == null : address.equals(cmp.address)) ) 127 return false; 128 if ( !(broadcast == null ? cmp.broadcast == null : broadcast.equals(cmp.broadcast)) ) 129 return false; 130 if (maskLength != cmp.maskLength) 131 return false; 132 return true; 133 } 134 135 /** 136 * Returns a hashcode for this Interface address. 137 * 138 * @return a hash code value for this Interface address. 139 */ 140 public int hashCode() { 141 return address.hashCode() + ((broadcast != null) ? broadcast.hashCode() : 0) + maskLength; 142 } 143 144 /** 145 * Converts this Interface address to a {@code String}. The 146 * string returned is of the form: InetAddress / prefix length [ broadcast address ]. 147 * 148 * @return a string representation of this Interface address. 149 */ 150 public String toString() { 151 return address + "/" + maskLength + " [" + broadcast + "]"; 152 } 153 154 } 155
