Java example source code file (InterfaceAddress.java)

This example Java source code file (InterfaceAddress.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

inet4address, inetaddress, interfaceaddress, string

The InterfaceAddress.java Java example source code

/*
 * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package java.net;

/**
 * This class represents a Network Interface address. In short it's an
 * IP address, a subnet mask and a broadcast address when the address is
 * an IPv4 one. An IP address and a network prefix length in the case
 * of IPv6 address.
 *
 * @see java.net.NetworkInterface
 * @since 1.6
 */
public class InterfaceAddress {
    private InetAddress address = null;
    private Inet4Address broadcast = null;
    private short        maskLength = 0;

    /*
     * Package private constructor. Can't be built directly, instances are
     * obtained through the NetworkInterface class.
     */
    InterfaceAddress() {
    }

    /**
     * Returns an {@code InetAddress} for this address.
     *
     * @return the {@code InetAddress} for this address.
     */
    public InetAddress getAddress() {
        return address;
    }

    /**
     * Returns an {@code InetAddress} for the broadcast address
     * for this InterfaceAddress.
     * <p>
     * Only IPv4 networks have broadcast address therefore, in the case
     * of an IPv6 network, {@code null} will be returned.
     *
     * @return the {@code InetAddress} representing the broadcast
     *         address or {@code null} if there is no broadcast address.
     */
    public InetAddress getBroadcast() {
        return broadcast;
    }

    /**
     * Returns the network prefix length for this address. This is also known
     * as the subnet mask in the context of IPv4 addresses.
     * Typical IPv4 values would be 8 (255.0.0.0), 16 (255.255.0.0)
     * or 24 (255.255.255.0). <p>
     * Typical IPv6 values would be 128 (::1/128) or 10 (fe80::203:baff:fe27:1243/10)
     *
     * @return a {@code short} representing the prefix length for the
     *         subnet of that address.
     */
     public short getNetworkPrefixLength() {
        return maskLength;
    }

    /**
     * Compares this object against the specified object.
     * The result is {@code true} if and only if the argument is
     * not {@code null} and it represents the same interface address as
     * this object.
     * <p>
     * Two instances of {@code InterfaceAddress} represent the same
     * address if the InetAddress, the prefix length and the broadcast are
     * the same for both.
     *
     * @param   obj   the object to compare against.
     * @return  {@code true} if the objects are the same;
     *          {@code false} otherwise.
     * @see     java.net.InterfaceAddress#hashCode()
     */
    public boolean equals(Object obj) {
        if (!(obj instanceof InterfaceAddress)) {
            return false;
        }
        InterfaceAddress cmp = (InterfaceAddress) obj;
        if ( !(address == null ? cmp.address == null : address.equals(cmp.address)) )
            return false;
        if ( !(broadcast  == null ? cmp.broadcast == null : broadcast.equals(cmp.broadcast)) )
            return false;
        if (maskLength != cmp.maskLength)
            return false;
        return true;
    }

    /**
     * Returns a hashcode for this Interface address.
     *
     * @return  a hash code value for this Interface address.
     */
    public int hashCode() {
        return address.hashCode() + ((broadcast != null) ? broadcast.hashCode() : 0) + maskLength;
    }

    /**
     * Converts this Interface address to a {@code String}. The
     * string returned is of the form: InetAddress / prefix length [ broadcast address ].
     *
     * @return  a string representation of this Interface address.
     */
    public String toString() {
        return address + "/" + maskLength + " [" + broadcast + "]";
    }

}