您好，我正在尝试从 android 中查找连接到我的 WIFI 路由器的所有设备，我需要设备 Mac 地址和每个设备(包括 iOT 设备)的本地 ip 地址， 现在，我正在尝试从 ARP 缓存表中查找。但有时在扫描中会丢失一些设备，因此不太准确。

我的代码:

 List<LocalDeviceInfo> devicesInfos = new ArrayList<>();


        BufferedReader bufferedReader = null;

        try {
            bufferedReader = new BufferedReader(new FileReader("/proc/net/arp"));

            String line;
            while ((line = bufferedReader.readLine()) != null) {
                String[] splitted = line.split(" +");
                if (splitted != null && splitted.length >= 4) {
                    String ip = splitted[0];
                    String mac = splitted[3];
                    if (mac.matches("..:..:..:..:..:..")) {
                        LocalDeviceInfo thisNode = new LocalDeviceInfo(ip, mac);
                        devicesInfos.add(thisNode);
                    }
                }
            }

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally{
            try {
                bufferedReader.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        // Print Description
        for (LocalDeviceInfo devicesInfo :devicesInfos)
        {
            System.out.print("✅");
            System.out.println("IP : "+devicesInfo.getIp());
            System.out.println("Mac : "+devicesInfo.getMacAddress());
        }

How can i scan all devices (IP address and Mac address) in android accurately .

最佳答案

我找到了我的问题的解决方案，大多数设备不在系统 arp 表中，所以你需要在第一次 Ping 每个设备，一旦你 ping 该设备，它就会存储在系统 ARP 表中在(/proc/net/arp)

用 ip ping 所有设备:(首先你需要找到你设备的 IP 地址，然后你可以确定子网掩码，然后你可以从 (0-255) 开始 pining

代码:

public  void startPingService(Context context)
{
  List<LocalDeviceInfo> deviceInfoList  = new ArrayList<LocalDeviceInfo>();
    try {

        WifiManager mWifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
        WifiInfo mWifiInfo = mWifiManager.getConnectionInfo();
        String subnet = getSubnetAddress(mWifiManager.getDhcpInfo().gateway);


        for (int i=1;i<255;i++){

            String host = subnet + "." + i;

            if (InetAddress.getByName(host).isReachable(timeout)){

                String strMacAddress = getMacAddressFromIP(host);

                Log.w("DeviceDiscovery", "Reachable Host: " + String.valueOf(host) +" and Mac : "+strMacAddress+" is reachable!");

                    LocalDeviceInfo localDeviceInfo = new LocalDeviceInfo(host,strMacAddress);
                    deviceInfoList.add(localDeviceInfo);
             }
            else
            {
                Log.e("DeviceDiscovery", "❌ Not Reachable Host: " + String.valueOf(host));

            }
        }


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


}


private String getSubnetAddress(int address)
{
    String ipString = String.format(
            "%d.%d.%d",
            (address & 0xff),
            (address >> 8 & 0xff),
            (address >> 16 & 0xff));

    return ipString;
}

从 ARP 缓存表中获取 Mac 地址

public String getMacAddressFromIP(@NonNull String ipFinding)
{

    Log.i("IPScanning","Scan was started!");
    List<LocalDeviceInfo> antarDevicesInfos = new ArrayList<>();


    BufferedReader bufferedReader = null;

    try {
        bufferedReader = new BufferedReader(new FileReader("/proc/net/arp"));

        String line;
        while ((line = bufferedReader.readLine()) != null) {
            String[] splitted = line.split(" +");
            if (splitted != null && splitted.length >= 4) {
                String ip = splitted[0];
                String mac = splitted[3];
                if (mac.matches("..:..:..:..:..:..")) {

                    if (ip.equalsIgnoreCase(ipFinding))
                    {
                        return mac;
                    }
                }
            }
        }

    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } finally{
        try {
            bufferedReader.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    return "00:00:00:00";
}

您也需要这些权限:

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

关于java - 如何在android中准确扫描所有连接到wifi的设备的IP和Mac地址？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/51685723/