java - Android 9.0 wifi hotspot API

Question

What is the API call I need to make in Android 9.0 (Android P) to get a Wifi hotspot name?

public static String getWifiApSSID(Context context) {
        try {
            WifiManager manager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
            Method method = manager.getClass().getDeclaredMethod("getWifiApConfiguration");
            WifiConfiguration configuration = (WifiConfiguration) method.invoke(manager);
            if (configuration != null) {
                return configuration.SSID;
            }
        } catch (NoSuchMethodException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
        return "";
    }

Android 9.0 returns "".

Answer 1

You're using reflection method getWifiApiConfiguration which doesn't works for API>=26. Good news, for API>=26, you don't need to use reflection. You can just use the public exposed API by android i.e. startLocalOnlyHotspot

It requires Manifest.permission.CHANGE_WIFI_STATE and ACCESS_FINE_LOCATION permissions.

Here's a simple example of how you can turn on hotspot using this API.

    private WifiManager wifiManager;
WifiConfiguration currentConfig;
WifiManager.LocalOnlyHotspotReservation hotspotReservation;

The method to turn on hotspot:

`
@RequiresApi(api = Build.VERSION_CODES.O)
public void turnOnHotspot() {

      wifiManager.startLocalOnlyHotspot(new WifiManager.LocalOnlyHotspotCallback() {

        @Override
        public void onStarted(WifiManager.LocalOnlyHotspotReservation reservation) {
          super.onStarted(reservation);
          hotspotReservation = reservation;
          currentConfig = hotspotReservation.getWifiConfiguration();

          Log.v("DANG", "THE PASSWORD IS: "
              + currentConfig.preSharedKey
              + " 
 SSID is : "
              + currentConfig.SSID);

          hotspotDetailsDialog();

        }

        @Override
        public void onStopped() {
          super.onStopped();
          Log.v("DANG", "Local Hotspot Stopped");
        }

        @Override
        public void onFailed(int reason) {
          super.onFailed(reason);
          Log.v("DANG", "Local Hotspot failed to start");
        }
      }, new Handler());
    }
`

Here's how you can get details of the locally created hotspot

private void hotspotDetaisDialog()
{

    Log.v(TAG, context.getString(R.string.hotspot_details_message) + "
" + context.getString(
              R.string.hotspot_ssid_label) + " " + currentConfig.SSID + "
" + context.getString(
              R.string.hotspot_pass_label) + " " + currentConfig.preSharedKey);

}
`

I recently created a demo app called Spotserve. That turns on wifi hotspot for all devices with API>=15 and hosts a demo server on that hotspot. You can check that for more details. Hope this helps!