Question

我想获取我的MAC地址。我用下面的代码来做到这一点。但是我得到的输出为FF。这不是我的mac地址。 xx:xx:xx:xx:xx:ff是我的mac地址。

public String getMacAddress() {
    Enumeration<NetworkInterface> networks = null;
    String macaddress=null;
    try {
        networks = NetworkInterface.getNetworkInterfaces();
    } catch (SocketException e) {
        e.printStackTrace();
    }
    NetworkInterface inter;
    while (networks.hasMoreElements()) {
        inter = networks.nextElement();
        byte[] mac = null;
        try {
            mac = inter.getHardwareAddress();
        } catch (SocketException e) {
            e.printStackTrace();
        }
        if (mac != null) {
            for (int i = 0; i < mac.length; i++) {
                macaddress=String.format("%02X%s", mac[i], (i < mac.length - 1) ? "-" : "");
            }
            System.out.println("");
        }
    }
    return macaddress;
}

如何获取我的MAC地址？

Answer 1

我发现了：

package com.mkyong;

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

public class App{

public static void main(String[] args){

InetAddress ip;
try {

    ip = InetAddress.getLocalHost();
    System.out.println("Current IP address : " + ip.getHostAddress());

    NetworkInterface network = NetworkInterface.getByInetAddress(ip);

    byte[] mac = network.getHardwareAddress();

    System.out.print("Current MAC address : ");

    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();

  }

 }
}

输出：

当前IP地址：192.168.1.22 当前的MAC地址：00-26-B9-9B-61-BF

Answer 2

我看到两个问题。

首先，您要重新分配macaddress的值。意味着总是只有mac的最后一个字节。第二个问题是您要遍历计算机具有的所有接口，因此即使您更改了

macaddress = String.format("%02X%s", mac[i], (i < mac.length - 1) ? "-" : "");
macaddress += String.format("%02X%s", mac[i], (i < mac.length - 1) ? "-" : "");

要附加而不是分配，您将获得一个包含计算机具有的所有MAC地址的字符串。另外，您还必须将macaddress初始化为空字符串（因为您不能追加到null）。

由于要遍历所有接口，如何返回Collection而不是单个String？另外使用StringBuilder可能更合适。

public List<String> getMacAddress() { // Change return type from String to List<String>
    Enumeration<NetworkInterface> networks = null;
    try {
        networks = NetworkInterface.getNetworkInterfaces();
    } catch (SocketException e) {
        e.printStackTrace();
    }
    NetworkInterface inter;
    List<String> addresses = new ArrayList<>(); // Create list to store all MAC addresses
    while (networks.hasMoreElements()) {
        inter = networks.nextElement();
        byte[] mac = null;
        try {
            mac = inter.getHardwareAddress();
        } catch (SocketException e) {
            e.printStackTrace();
        }
        if (mac != null) {
            StringBuilder sb = new StringBuilder(); // Rather than appending with += use a String builder
            for (int i = 0; i < mac.length; i++) {
                sb.append(String.format("%02X%s", mac[i], (i < mac.length - 1) ? "-" : "")); // Use append on the string builder
            }
            addresses.add(sb.toString()); // Add MAC address to the Collection
        }
    }
    return addresses; // Return collection rather than one String
}

如何获得计算机的MAC地址？

2 个答案: