Java如何获取客户端mac地址

String getMacInfo(HttpServletRequest request)
    {
        //获取ip地址
        String macInfo = null;
        try
        {
            String ip = request.getRemoteAddr();
            //linux下获取mac地址
            macAddr = CommonUtils.getMac(ip);
            //windows下获取mac地址
            if(StringUtils.isBlank(macAddr)){
                macAddr = CommonUtils.getMacInWindows(ip).trim();
            }
        }
        catch (Exception e)
        {
            log.error("获取mac地址失败");
            return null;
        }
        return macInfo;
    }

	// 从类unix机器上获取mac地址
	 public static String getMac(String ip) throws IOException {
        String mac = SysCode.BDFH.EMPTY;
        if (ip != null) {
            try {
                Process process = Runtime.getRuntime().exec("arp "+ip);
                InputStreamReader ir = new InputStreamReader(process.getInputStream());
                LineNumberReader input = new LineNumberReader(ir);
                String line;
                StringBuffer s = new StringBuffer();
                while ((line = input.readLine()) != null) {
                    s.append(line);
                }
                mac = s.toString();
                if (StringUtils.isNotBlank(mac)) {
                    mac = mac.substring(mac.indexOf(":") - 2, mac.lastIndexOf(":") + 3);
                }
                return mac;
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return mac;
    }
    
    // 从windows机器上获取mac地址
	public static String getMacInWindows(final String ip) {
        String result = "";
        String[] cmd = {"cmd", "/c", "ping " + ip};
        String[] another = {"cmd", "/c", "ipconfig -all"};
        // 获取执行命令后的result
        String cmdResult = callCmd(cmd, another);
        // 从上一步的结果中获取mac地址
        result = filterMacAddress(ip, cmdResult, "-");
        return result;
 	}
 	
 	// 命令执行
 	public static String callCmd(String[] cmd, String[] another) {
        String result = "";
        String line = "";
        try {
            Runtime rt = Runtime.getRuntime();
            // 执行第一个命令
            Process proc = rt.exec(cmd);
            proc.waitFor();
             // 执行第二个命令
            proc = rt.exec(another);
            InputStreamReader is = new InputStreamReader(proc.getInputStream());
            BufferedReader br = new BufferedReader(is);
            while ((line = br.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result;
    }
	
	// 获取mac地址
	public static String filterMacAddress(final String ip, final String sourceString, final String macSeparator) {
        String result = "";
        String regExp = "((([0-9,A-F,a-f]{1,2}" + macSeparator + "){1,5})[0-9,A-F,a-f]{1,2})";
        Pattern pattern = Pattern.compile(regExp);
        Matcher matcher = pattern.matcher(sourceString);
        while (matcher.find()) {
            result = matcher.group(1);
            // 因计算机多网卡问题，截取紧靠IP后的第一个mac地址
            int num = sourceString.indexOf(ip) - sourceString.indexOf(": "+result + " ");
            if (num>0&&num<300) {
                break;
            }
        }
        return result;
    }