Java Utililty Methods Mac Address Get

StringBuilder sb = new StringBuilder();
try {
    InetAddress ip = InetAddress.getLocalHost();
    NetworkInterface network = NetworkInterface.getByInetAddress(ip);
    byte[] mac = network.getHardwareAddress();
    for (int i = 0; i < mac.length; i++) {
        sb.append(String.format("%02X%s", mac[i], (i < mac.length - 1) ? "-" : ""));
} catch (SocketException | UnknownHostException e) {
return sb.toString();

String macAddr = "";
String str = "";
try {
    NetworkInterface nic = NetworkInterface.getByName("eth0");
    if (nic != null) {
        byte[] buf = nic.getHardwareAddress();
        if (buf != null) {
            for (int i = 0; i < buf.length; i++) {
...

String result = "";
try {
    for (NetworkInterface ni : Collections.list(NetworkInterface.getNetworkInterfaces())) {
        byte[] hardwareAddress = ni.getHardwareAddress();
        if (hardwareAddress != null) {
            for (int i = 0; i < hardwareAddress.length; i++)
                result += String.format((i == 0 ? "" : "-") + "%02X", hardwareAddress[i]);
            return result;
...

StringBuilder sb = new StringBuilder();
try {
    NetworkInterface network = NetworkInterface.getByInetAddress(ip);
    byte[] mac = network.getHardwareAddress();
    for (int i = 0; i < mac.length; i++) {
        sb.append(String.format("%02X%s", mac[i], (i < mac.length - 1) ? "-" : ""));
} catch (SocketException e) {
...

String os = System.getProperty("os.name");
try {
    if (os.startsWith("Windows")) {
        return windowsParseMacAddress(windowsRunIpConfigCommand());
    } else if (os.startsWith("Linux")) {
        return linuxParseMacAddress(linuxRunIfConfigCommand());
    } else {
        throw new IOException("unknown operating system: " + os);
...

if (macAddress == MAC_ADDRESS_DEFAULT) {
    try {
        Enumeration<NetworkInterface> interfaces = NetworkInterface.getNetworkInterfaces();
        byte[] mac = null;
        while (interfaces.hasMoreElements() && (mac == null || mac.length != 6)) {
            NetworkInterface netInterface = interfaces.nextElement();
            if (netInterface.isLoopback() || netInterface.isVirtual()) {
                continue;
...

if (macAddress == null) {
    try {
        fetchMacAddress();
    } catch (Exception e) {
        e.printStackTrace();
    if (macAddress == null) {
        macAddress = "unknown";
...

try {
    String mac = null;
    for (NetworkInterface ni : Collections.list(NetworkInterface.getNetworkInterfaces())) {
        if (ni.getHardwareAddress() != null) {
            byte[] hwAddr = ni.getHardwareAddress();
            if (hwAddr.length > 0) {
                mac = "";
                for (int i = 0; i < hwAddr.length; i++) {
...

if (cachedMacAddress != null && cachedMacAddress.length >= 10) {
    return cachedMacAddress;
try {
    Enumeration<NetworkInterface> networkInterfaces = NetworkInterface.getNetworkInterfaces();
    while (networkInterfaces.hasMoreElements()) {
        NetworkInterface network = networkInterfaces.nextElement();
        byte[] mac = network.getHardwareAddress();
...

return getMacAddress(InetAddress.getLocalHost());