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Android

Posted by Austin Aigbe
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Austin Aigbe
Front End Web Development Techdegree Student 1,065 Points

How to get the Connected Wifi Devices

Hello, I am using the wifi hotspot and tethering function on my Android phone to connect to the WAMP server running on my PC. Now, I need to get the connected device(s) to my phone's Wifi AP. How can I do this?

Currently, I am using reflection to check the state of the Wifi AP:

 public int getWifiAPState() {
        WifiManager wifi = (WifiManager) _context.getSystemService(Context.WIFI_SERVICE);
        int state = -1;
        try {
            Method method1 = wifi.getClass().getMethod("getWifiApState");
            state = (Integer) method1.invoke(wifi);           
        } catch (Exception e) {}
        Log.d("WifiAP", "getWifiAPState.state " + (state == -1 ? "UNKNOWN":WIFI_STATE_TEXTSTATE[state-10]));
        return state;
}

From the LogCat, I can see the WIfiStateMachine getConnectedWifiDevices result. How do I get this information programmatically?

Thanks.

Austin

2 Answers

Austin Aigbe
seal-mask
.a{fill-rule:evenodd;}techdegree
Austin Aigbe
Front End Web Development Techdegree Student 1,065 Points
Austin Aigbe
.a{fill-rule:evenodd;}techdegree
Austin Aigbe
Front End Web Development Techdegree Student 1,065 Points

Thanks Ben.

Currently, I am using the following piece of code to get the connected WiFi Device (in this case, my PC running a WAMP server):

     public boolean isConnectedToServer() {
        ArrayList<ClientScanResult> clients = getClientList(false);
        for (ClientScanResult clientScanResult : clients) {
            Log.d("IP Address", clientScanResult.getIpAddr());
             // IP address of my PC (192.148.43.20), running a WAMP server
            if (clientScanResult.getIpAddr().matches("192.148.43.20")){
                return true;
            }
        }
        return false;
    }

    public ArrayList<ClientScanResult> getClientList(boolean onlyReachables) {
        return getClientList(onlyReachables, 300);
    }


    /**
     * Gets a list of the clients connected to the Hotspot 
     * @param onlyReachables {@code false} if the list should contain unreachable (probably disconnected) clients, {@code true} otherwise
     * @param reachableTimeout Reachable Timout in miliseconds
     * @return ArrayList of {@link ClientScanResult}
     */
    public ArrayList<ClientScanResult> getClientList(boolean onlyReachables, int reachableTimeout) {
        BufferedReader br = null;
        ArrayList<ClientScanResult> result = null;

        try {
            result = new ArrayList<ClientScanResult>();
            br = new BufferedReader(new FileReader("/proc/net/arp"));
            String line;
            while ((line = br.readLine()) != null) {
                String[] splitted = line.split(" +");

                if ((splitted != null) && (splitted.length >= 4)) {
                    // Basic sanity check
                    String mac = splitted[3];

                    if (mac.matches("..:..:..:..:..:..")) {
                        boolean isReachable = InetAddress.getByName(splitted[0]).isReachable(reachableTimeout);

                        if (!onlyReachables || isReachable) {
                            result.add(new ClientScanResult(splitted[0], splitted[3], splitted[5], isReachable));
                        }
                    }
                }
            }
        } catch (Exception e) {
            Log.e(this.getClass().toString(), e.getMessage());
        } finally {
            try {
                br.close();
            } catch (IOException e) {
                Log.e(this.getClass().toString(), e.getMessage());
            }
        }

        return result;
    }
Ben Jakuben
STAFF
Ben Jakuben
Treehouse Teacher
Ben Jakuben
Ben Jakuben
Treehouse Teacher

I've never tried this, but perhaps you can try this library from GitHub: https://github.com/rorist/android-network-discovery