Java Mac Address Get getMacAddrs()

Description

Returns the hardware address (usually MAC) of the interface if it has one and if it can be accessed given the current privileges.

License

Apache License

Exception

Parameter	Description
SocketException	if an I/O error occurs.

Return

a char array containing the first address or null if the address doesn't exist or is not accessible.

Declaration

public static String[] getMacAddrs() throws SocketException

Method Source Code


//package com.java2s;
/*//from  w  w  w.  j av  a  2  s  .com
 * Copyright 2014 the original author or authors.
 *
 * 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.
 */

import java.net.NetworkInterface;
import java.net.SocketException;

import java.util.Enumeration;

public class Main {
    /**
     * Hex array
     */
    private final static char[] HEXARRAY = "0123456789ABCDEF".toCharArray();

    /**
     * Returns the hardware address (usually MAC) of the interface if it
     * has one and if it can be accessed given the current privileges.
     *
     * @return a char array containing the first address or <code>null</code> if
     * the address doesn't exist or is not accessible.
     * @throws SocketException if an I/O error occurs.
     * @since 1.6
     */
    public static String[] getMacAddrs() throws SocketException {
        Enumeration<NetworkInterface> e = NetworkInterface.getNetworkInterfaces();
        StringBuilder buf = new StringBuilder();
        while (e.hasMoreElements()) {
            NetworkInterface network = e.nextElement();
            if (network != null) {
                byte[] nmac = network.getHardwareAddress();
                if (nmac != null) {
                    buf.append(hexdump(nmac));
                    buf.append("#");
                }
            }
        }
        return buf.toString().split("#");
    }

    /**
     * Format bytes to hex byte
     *
     * @param bytes bytes
     * @return hex string
     */
    public static String hexdump(final byte[] bytes) {
        if (bytes == null || bytes.length < 1)
            return "[no data]";
        int length = bytes.length;

        int temp;
        char[] hex = new char[length * 2];
        for (int i = 0; i < length; i++) {

            // UnsignedByte
            temp = bytes[i] & 0xFF;

            hex[i * 2] = HEXARRAY[temp >>> 4];
            hex[i * 2 + 1] = HEXARRAY[temp & 0x0F];

        }
        return new String(hex);
    }
}