1 /*

     2  * Copyright 2005-2006 Sun Microsystems, Inc.  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.  Sun designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    22  * CA 95054 USA or visit www.sun.com if you need additional information or

    23  * have any 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     /**

    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) ||

   107             (!address.equals(cmp.address)))

   108             return false;

   109         if ((broadcast != null & cmp.broadcast == null) ||

   110             (!broadcast.equals(cmp.broadcast)))

   111             return false;

   112         if (maskLength != cmp.maskLength)

   113             return false;

   114         return true;

   115     }

   116 

   117     /**

   118      * Returns a hashcode for this Interface address.

   119      *

   120      * @return  a hash code value for this Interface address.

   121      */

   122     public int hashCode() {

   123         return address.hashCode() + ((broadcast != null) ? broadcast.hashCode() : 0) + maskLength;

   124     }

   125 

   126     /**

   127      * Converts this Interface address to a <code>String</code>. The

   128      * string returned is of the form: InetAddress / prefix length [ broadcast address ].

   129      *

   130      * @return  a string representation of this Interface address.

   131      */

   132     public String toString() {

   133         return address + "/" + maskLength + " [" + broadcast + "]";

   134     }

   135 

   136 }