如何讓機器的mac地址

Question

我想拿到機器的MAC address..but低於當Internet連接到其他的我的機器編寫的代碼僅顯示MAC地址，將返回空...我使用Windows 7

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

class test 
{ 
    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(); 
     } 
    } 
} 

Answer 1

好像你正試圖通過IP地址獲取MAC地址。一個IP地址存在只有當你連接成功到互聯網。否則，如您所述，它將是null。

試試這個：NetworkInterface.getHardwareAddress()。

如果您想要計算機上所有網絡接口的MAC地址，請嘗試以下操作：NetworkInterface.getNetworkInterfaces()。

---

編輯：再次檢查代碼後，我才知道你有我的建議執行。但是，如果您擁有有效的IP，則您只會嘗試獲取MAC地址。如果沒有連接到互聯網，您將不會擁有有效的IP。

public static void main(String[] args) 
    { 
     NetworkInterface network; 
     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()); 
    } 

Answer 2

的問題可能是由一個事實，即當您的計算機沒有連接到互聯網，你的網卡沒有分配的IP地址造成的。你正試圖通過IP地址查找網絡接口。

我建議你列舉所有的網絡接口代替，並選擇一個你需要的：

import java.net.*; 
import java.util.*; 

public class App { 

    protected static String formatMac(byte[] mac) { 
     if (mac == null) 
      return "UNKNOWN"; 
     StringBuilder sb = new StringBuilder(); 
     for (int i = 0; i < mac.length; i++) { 
      sb.append(String.format("%02X%s", mac[i], (i < mac.length - 1) ? "-" : "")); 
     } 
     return sb.toString(); 
    } 

    public static void main(String[] args) throws Exception { 
     for(Enumeration<NetworkInterface> e 
        = NetworkInterface.getNetworkInterfaces(); 
       e.hasMoreElements();) 
     { 
      NetworkInterface ni = e.nextElement(); 
      System.out.println(ni.getName() + " - " + formatMac(ni.getHardwareAddress())); 
     } 
    } 
} 

這應該解決的問題和工作沒有任何互聯網連接。

Answer 3

試試這個應該在Linux和Windows

public static void main(String[] args) { 

    String command = "/sbin/ifconfig"; 

    String sOsName = System.getProperty("os.name"); 
    if (sOsName.startsWith("Windows")) { 
     command = "ipconfig"; 
    } else { 

     if ((sOsName.startsWith("Linux")) || (sOsName.startsWith("Mac")) 
       || (sOsName.startsWith("HP-UX"))) { 
      command = "/sbin/ifconfig"; 
     } else { 
      System.out.println("The current operating system '" + sOsName 
        + "' is not supported."); 
     } 
    } 

    Pattern p = Pattern 
      .compile("([a-fA-F0-9]{1,2}(-|:)){5}[a-fA-F0-9]{1,2}"); 
    try { 
     Process pa = Runtime.getRuntime().exec(command); 
     pa.waitFor(); 
     BufferedReader reader = new BufferedReader(new InputStreamReader(
       pa.getInputStream())); 

     String line; 
     Matcher m; 
     while ((line = reader.readLine()) != null) { 

      m = p.matcher(line); 

      if (!m.find()) 
       continue; 
      line = m.group(); 
      break; 

     } 
     System.out.println(line); 
    } catch (Exception e) { 
     e.printStackTrace(); 
    } 

}