Constructs an InetAddress object for the IP address specified in the network-byte-order array. - Java Network

Java examples for Network:IP Address

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Description

Constructs an InetAddress object for the IP address specified in the network-byte-order array.

Demo Code

/*/*w w w .  j ava2  s .co  m*/
 * NetCallback - forwarding TCP ports behind a firewall
 * Copyright (C) 2001 Alexander V. Konstantinou <akonstan@acm.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */
//package com.java2s;
import java.net.InetAddress;
import java.net.UnknownHostException;

public class Main {
    public static void main(String[] argv) throws Exception {
        byte[] address = new byte[] { 34, 35, 36, 37, 37, 37, 67, 68, 69 };
        System.out.println(getByAddress(address));
    }

    /**
     * Constructs an InetAddress object for the IP address specified in
     * the network-byte-order array.
     *
     * @param address - a 4-byte array in network byte order 
     *                 (highest order first)
     * @exception IllegalArgumentException - if the array address argument
     *                                       is not of length 4
     */
    public static InetAddress getByAddress(byte[] address) {
        try {
            InetAddress inet = InetAddress
                    .getByName(getDottedIPv4Address(address));
            return (inet);
        } catch (UnknownHostException e) {
            throw new RuntimeException(
                    "Internal error: unexpected exception on "
                            + "dotted IP address parsing: "
                            + e.getClass().getName() + ": "
                            + e.getMessage());
        }
    }

    /**
     * Returns the IP address string "%d.%d.%d.%d" for the given IPv4 address.
     *
     * @param address - a 4-byte array in network byte order 
     *                 (highest order first)
     * @exception IllegalArgumentException - if the array address argument
     *                                       is not of length 4
     */
    public static String getDottedIPv4Address(byte[] address) {
        if (address == null) {
            throw new NullPointerException("null address argument");
        }

        if (address.length != 4) {
            throw new IllegalArgumentException(
                    "Invalid IPv4 address length " + address.length);
        }

        return ((address[0] & 0xFF) + "." + (address[1] & 0xFF) + "."
                + (address[2] & 0xFF) + "." + (address[3] & 0xFF));
    }
}

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