java - 如何查找远程系统 MAC 地址

Question

我可以使用下面的代码获取本地 MAC 地址

package com.eiw.server;

import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.net.UnknownHostException;

class FindMACAddress {
    public static void main(String[] args) {
        InetAddress ip;
        try {
            ip = InetAddress.getLocalHost();

            System.out.println("The mac Address of this machine is :"
                    + ip.getHostAddress());

            NetworkInterface network = NetworkInterface.getByInetAddress(ip);

            byte[] mac = network.getHardwareAddress();

            System.out.print("The mac address is : ");

            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < mac.length; i++) {
                sb.append(String.format("%02X%s", mac[i],
                        (i < mac.length - 1) ? "-" : ""));
            }

            System.out.println(sb.toString());

        } catch (UnknownHostException e) {
            e.printStackTrace();
        } catch (SocketException e) {
            e.printStackTrace();
        }
    }
}

但我需要找到远程系统的 Mac 地址...是否可能？我已经浏览了一些帖子...但不清楚...

Answer 1

可以调用函数getMacAddrHost("192.168.1.xx")获取远程主机的mac addr。这可能不是最好的解决方案，但效果很好。请注意，这仅适用于 LAN 内部。

public static String getMacAddrHost(String host) throws IOException, InterruptedException {
        //
        boolean ok = ping3(host);
        //
        if (ok) {
            InetAddress address = InetAddress.getByName(host);
            String ip = address.getHostAddress();
            return run_program_with_catching_output("arp -a " + ip);
        }
        //
        return null;
        //
    }


 public static boolean ping3(String host) throws IOException, InterruptedException {
        boolean isWindows = System.getProperty("os.name").toLowerCase().contains("win");

        ProcessBuilder processBuilder = new ProcessBuilder("ping", isWindows ? "-n" : "-c", "1", host);
        Process proc = processBuilder.start();

        int returnVal = proc.waitFor();
        return returnVal == 0;
    }

    public static String run_program_with_catching_output(String param) throws IOException {
        Process p = Runtime.getRuntime().exec(param);
        BufferedReader input = new BufferedReader(new InputStreamReader(p.getInputStream()));
        String line;
        while ((line = input.readLine()) != null) {
            if (!line.trim().equals("")) {
                // keep only the process name
                line = line.substring(1);
                String mac = extractMacAddr(line);
                if (mac.isEmpty() == false) {
                    return mac;
                }
            }

        }
        return null;
    }

    public static String extractMacAddr(String str) {
        String arr[] = str.split("   ");
        for (String string : arr) {
            if (string.trim().length() == 17) {
                return string.trim().toUpperCase();
            }
        }
        return "";
    }