1/*
2 * Copyright (c) 2005, 2008, 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
26package 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 */
37public 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    /**
50     * Returns an <code>InetAddress</code> for this address.
51     *
52     * @return the <code>InetAddress</code> for this address.
53     */
54    public InetAddress getAddress() {
55        return address;
56    }
57
58    /**
59     * Returns an <code>InetAddress</code> for the brodcast address
60     * for this InterfaceAddress.
61     * <p>
62     * Only IPv4 networks have broadcast address therefore, in the case
63     * of an IPv6 network, <code>null</code> will be returned.
64     *
65     * @return the <code>InetAddress</code> representing the broadcast
66     *         address or <code>null</code> if there is no broadcast address.
67     */
68    public InetAddress getBroadcast() {
69        return broadcast;
70    }
71
72    /**
73     * Returns the network prefix length for this address. This is also known
74     * as the subnet mask in the context of IPv4 addresses.
75     * Typical IPv4 values would be 8 (255.0.0.0), 16 (255.255.0.0)
76     * or 24 (255.255.255.0). <p>
77     * Typical IPv6 values would be 128 (::1/128) or 10 (fe80::203:baff:fe27:1243/10)
78     *
79     * @return a <code>short</code> representing the prefix length for the
80     *         subnet of that address.
81     */
82     public short getNetworkPrefixLength() {
83        return maskLength;
84    }
85
86    /**
87     * Compares this object against the specified object.
88     * The result is <code>true</code> if and only if the argument is
89     * not <code>null</code> and it represents the same interface address as
90     * this object.
91     * <p>
92     * Two instances of <code>InterfaceAddress</code> represent the same
93     * address if the InetAddress, the prefix length and the broadcast are
94     * the same for both.
95     *
96     * @param   obj   the object to compare against.
97     * @return  <code>true</code> if the objects are the same;
98     *          <code>false</code> otherwise.
99     * @see     java.net.InterfaceAddress#hashCode()
100     */
101    public boolean equals(Object obj) {
102        if (!(obj instanceof InterfaceAddress)) {
103            return false;
104        }
105        InterfaceAddress cmp = (InterfaceAddress) obj;
106        if ( !(address == null ? cmp.address == null : address.equals(cmp.address)) )
107            return false;
108        if ( !(broadcast  == null ? cmp.broadcast == null : broadcast.equals(cmp.broadcast)) )
109            return false;
110        if (maskLength != cmp.maskLength)
111            return false;
112        return true;
113    }
114
115    /**
116     * Returns a hashcode for this Interface address.
117     *
118     * @return  a hash code value for this Interface address.
119     */
120    public int hashCode() {
121        return address.hashCode() + ((broadcast != null) ? broadcast.hashCode() : 0) + maskLength;
122    }
123
124    /**
125     * Converts this Interface address to a <code>String</code>. The
126     * string returned is of the form: InetAddress / prefix length [ broadcast address ].
127     *
128     * @return  a string representation of this Interface address.
129     */
130    public String toString() {
131        return address + "/" + maskLength + " [" + broadcast + "]";
132    }
133
134}
135