Compute network address from IP and mask - Java Network

Java examples for Network:IP Address

  1. HOME
  2. Java
  3. Network
  4. IP Address

Description

Compute network address from IP and mask

Demo Code

/**/*from  www  .  j a  v a 2s. c o  m*/
 * Copyright 2009-2011 ?cole de technologie sup?rieure,
 * Communication Research Centre Canada,
 * Inocybe Technologies Inc. and 6837247 CANADA Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
//package com.java2s;
import java.net.InetAddress;

public class Main {
    /**
     * Compute network address from IP and mask
     * @param ip
     * @param mask
     * @return
     */
    public static String computeNetworkAddress(InetAddress ip,
            InetAddress mask) {
        int addr = InetAddressToInt(ip);
        int maskInt = InetAddressToInt(mask);
        return IpToString(addr & maskInt);
    }

    /** Convert ip to an integer
     * @param ip InetAddress to convert
     * @return Integer
     */
    public static int InetAddressToInt(InetAddress ip) {
        if (ip == null)
            return -1;
        byte[] adr = ip.getAddress();

        int[] i = new int[4];
        for (int j = 0; j < 4; j++) {
            i[j] = (int) ((adr[j] < 0) ? (256 + adr[j]) : adr[j]);
        }
        return i[3] + (i[2] << 8) + (i[1] << 16) + (i[0] << 24);
    }

    /**
     * Convert an IP address stored in an int to its string representation.
     * @param address
     * @return
     */
    public static String IpToString(int address) {
        StringBuffer sa = new StringBuffer();
        for (int i = 0; i < 4; i++) {
            sa.append(0xff & address >> 24);
            address <<= 8;
            if (i != 4 - 1)
                sa.append('.');
        }
        return sa.toString();
    }
}

Related Tutorials