请问JAVA中如何获取到本机网卡的MAC码???

try {      Process p1 = Runtime.getRuntime().exec("ipconfig /all");
      BufferedReader br=new BufferedReader(new InputStreamReader(p1.getInputStream()));
      String buf=br.readLine();
      while(buf!=null){
        System.out.println(buf);
        buf=br.readLine();
      }
    }
    catch (Exception e) {    }