/**
 * 獲取 mac 地址工具類 v1 版
 *
 * @date 2021/5/13
 * @author zjw
 */
public class MacUtil {

    public static void main(String[] args) {
        getMac().forEach(System.out::println);
    }

    /**
     * 獲取本機(jī) mac 地址集合
     *
     * @return mac 地址集合
     */
    public static List<String> getMac() {
        List<String> list = new ArrayList<>();
        try {
            Enumeration<NetworkInterface> networkInterfaces = NetworkInterface.getNetworkInterfaces();
            while (networkInterfaces.hasMoreElements()) {
                NetworkInterface networkInterface = networkInterfaces.nextElement();
                Optional.ofNullable(networkInterface.getHardwareAddress())
                        .ifPresent(mac -> list.add(format(mac)));
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return list;
    }

    /**
     * 將 mac 字節(jié)數(shù)組格式化為全大寫并且使用 - 作為分隔符的字符串
     *
	 * @param mac 獲取到的 mac 字節(jié)數(shù)組
     *
     * @return 格式化后的 mac 地址
     */
    private static String format(byte[] mac) {
        StringBuilder sb = new StringBuilder();
        for (byte b : mac) {
            sb.append(String.format("%02X", b)).append("-");
        }
        sb.deleteCharAt(sb.length() - 1);
        return sb.toString();
    }

}

/**
 * 獲取 mac 地址工具類 v2 版
 *
 * @date 2021/5/13
 * @author zjw
 */
public class MacUtil {

    private static final String WIN_PREFIX = "win";
    private static final String OS_NAME_PROPERTY = "os.name";
    private static final String WIN_COMMAND = "ipconfig /all";
    private static final String UNIX_COMMAND = "/sbin/ifconfig -a";
    private static final String MAC_REGEX = "(([a-f0-9]{2}-){5}|([a-f0-9]{2}:){5})[a-f0-9]{2}";
    private static final Pattern pattern = Pattern.compile(MAC_REGEX, Pattern.CASE_INSENSITIVE);

    public static void main(String[] args) {
        getMac().forEach(System.out::println);
    }

    /**
     * 根據(jù)不同操作系統(tǒng)執(zhí)行不同命令
     * 獲取本機(jī) mac 地址集合
     *
     * @return mac 地址集合
     */
    private static List<String> getMac() {
        try {
            String osName = System.getProperty(OS_NAME_PROPERTY).toLowerCase();
            if (osName.startsWith(WIN_PREFIX)) {
                return getMacByCommand(WIN_COMMAND);
            }
            return getMacByCommand(UNIX_COMMAND);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return Collections.emptyList();
    }

    /**
     * 通過正則表達(dá)式提取執(zhí)行命令得到的結(jié)果集中的 mac 地址
     * 并調(diào)整得到的 mac 地址的格式
     *
	 * @param command 查看網(wǎng)絡(luò)信息的命令
     *
     * @return mac 地址集合
     */
    private static List<String> getMacByCommand(String command) throws IOException {
        List<String> macList = new ArrayList<>();
        List<String> strList = execCommand(command);
        for (String str : strList) {
            Matcher matcher = pattern.matcher(str);
            if (matcher.find() && matcher.end() == str.length()) {
                macList.add(matcher.group().replace(":", "-").toUpperCase());
            }
        }
        return macList;
    }

    /**
     * 執(zhí)行命令并得到結(jié)果的每一行組成的字符串?dāng)?shù)組
     *
	 * @param command 查看網(wǎng)絡(luò)信息的命令
     *
     * @return 執(zhí)行命令返回的所有數(shù)據(jù)行
     */
    private static List<String> execCommand(String command) throws IOException {
        List<String> strList = new ArrayList<>();
        Process process = Runtime.getRuntime().exec(command);
        try (BufferedReader br = new BufferedReader(new InputStreamReader(process.getInputStream()))) {
            return br.lines().collect(Collectors.toList());
        } catch (Exception e) {
            e.printStackTrace();
        }
        process.destroy();
        return strList;
    }

}