JAVA在win7中获取mac 物理地址

public static String getWindowsMACAddress() {

        String mac = null;
        BufferedReader bufferedReader = null;
        Process process = null;
        try {
            /**
             * windows下的命令，显示信息中包含有mac地址信息
             */
            process = Runtime.getRuntime().exec("ipconfig /all");
            bufferedReader = new BufferedReader(new InputStreamReader(
                    process.getInputStream(),"GB2312"));
            String line = null;
            int index = -1;
            while ((line = bufferedReader.readLine()) != null) {
                /**
                 * 寻找标示字符串[physical address]
                 */
                System.out.println(line);
                //index = line.toLowerCase().indexOf("physical address");
                index=line.indexOf("物理地址"); //在其他系统中可以在此做对应的修改
                if (index != -1) {
                    index = line.indexOf(":");
                    if (index != -1) {
                        /**
                         * 取出mac地址并去除2边空格
                         */
                        mac = line.substring(index + 1).trim();
                    }
                    break;
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (bufferedReader != null) {
                    bufferedReader.close();
                }
            } catch (IOException e1) {
                e1.printStackTrace();
            }
            bufferedReader = null;
            process = null;
        }

        return mac;
    }